2017 RMRM Final Program - 2017 Rocky Mountain …rmrm2017.sites.acs.org/2017 RMRM Final Program.pdf · Dear Rocky Mountain Regional Meeting participants, ... Selenium uptake by the

Program Booklet

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Table of Contents Letters of Welcome 3 Quick Overview of Schedule 5 Map of Hotel 6 Map of Area 7 Schedule of Events 8 Abstracts 28 Author Index 155

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American Chemical Society 1155 SIXTEENTH STREET, N.W. OFFICE OF THE PRESIDENT WASHINGTON, D.C. 20036 Phone 202-872-4461 Allison A. Campbell, Ph.D. Fax 202-872-6338 President-Elect, 2016 President, 2017 Immediate Past President, 2018 October 25, 2017 Dear Rocky Mountain Regional Meeting participants, On behalf of the more than 156,000 members of the American Chemical Society, I am happy to welcome you the Rocky Mountain Regional Meeting in beautiful Loveland, Colorado. The theme of the meeting, Energy in the Rockies, will highlight advances and the application of chemistry to the production, management, evaluation, and study of energy. In addition to nine technical symposia, six general sessions, and numerous poster sessions, the meeting will feature a high school teachers symposium, undergraduate programming, an awards banquet, a joint Younger Chemists Committee and Women Chemists Committee breakfast, a Senior Chemists Committee luncheon, and a welcome reception and poster session. Symposium sessions will include Biomaterials for Energy Production, Nanomaterials,Energy Production from Solar Radiation, Chemistry & the Environment,The Future of Chemical Education Chemical Analysis of Beer & Brewing Products, Young Scholars Symposium, Inhibitor Design & Studies in Medicinal Chemistry, and Radioanalytical Nuclear Chemistry Join your colleagues in celebration of the hard work and dedication to those volunteers being awarded the Stanley C. Israel Regional Award for Advancing Diversity in the Chemical Science, the Division of Chemical Education Excellence in High School Teaching Award, the E. Ann Nalley Rocky Mountain Regional Award for Volunteer Service, and the Partners for Progress & Prosperity Award. With all these events and great symposia, I want to express my special thanks to the RMRM chair Michael Mosher and to our host the Colorado Section for their hard work and dedication to create a great experience here in Loveland. Best wishes for a very successful RMRM 2017! Sincerely,

Allison A. Campbell, Ph.D. 2017 President

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American Chemical Society

MichaelMosherProfessorofChemistryDepartmentofChemistryandBiochemistryUniversityofNorthernColoradoGreeley,CO80639DearRMRMAttendee,TheColoradoSectionoftheAmericanChemicalSocietyispleasedtohosttheRockyMountainRegionalMeeting2017.Thethemeforthisyear’smeetingisEnergyintheRockies.MajortopicsforthemeetingincludeEnergyProduction,ChemicalEducation,andtheChemistryofFermentedProducts.ProminentplenaryspeakersfrominandaroundtheRockyMountainregionwillbeinattendanceaswellasscientistsfromacademia,government,andindustry.Theprogramwillincludeinterestingandtimelyresearchaccountsandupdatesfromresearchscientistsrepresentingallthemajorfieldsofchemicalscience.WehopeyoualsohaveachancetovisittheexhibitionandpostersessionsinPinyonPine.Thisexhibitionshowcasesvendorsfromaroundtheareaandevensomegraduateschools.Coffeebreaksandsnackscanbefoundinsideifyoufeellikearefreshment.TheACSisalsohostingaCareerWorkshopduringourmeetingonFriday.Themorningwillinvolveworkshopstoassistwithbuildingyourresumeandplanningyourcareer.Theafternoonwillinvolveresumereviewsessionswhereyoucanreceivefeedback.WechoseLoveland,Coloradoasthesiteofthemeetingbecauseofthenumberofactivitiesthatareavailabletoyouduringyourvisit.EstesParkisonlya35-40mindriveupintothemountains.FortCollins,Loveland,Windsor,andGreeleyareallwithinaveryshortdriveandarehometoalargenumberofbreweriesandactivitiesfortheentirefamily.Pleasetakethetimetoexploreifyoucan.Again,welcometothemeeting.Ihopeitisasexcitingtoyouasitisforustohost.Sincerely,

MichaelMosherGeneralChair,2017RMRM

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Symposium/Event WedEve ThuAM ThuPM FriAM FriPM SatAMInhibitorDesignandStudiesinMedChem

1:30-5:20AspenDaisy

Catalysts&GreenChemistry

8:30-11:45Elderberry

1:30-4:45Elderberry

FutureofChemEd 8:30-11:30Goldenglow

1:30-4:10Goldenglow

ChemistryofEnvironment

10:15-11:15RiverBirchA

Nanomaterials 8:30-12:00RiverBirchC

1:30-4:50RiverBirchC

EnergyfromSolarRadiation


BiomaterialsforEnergyProduction


RadioanalyticalNuclearChemistry

8:30-12:00RiverBirchB

ChemistryofBeer 1:30-5:30RiverBirchA

YoungInvestigators 8:30-11:45Snowberry

1:30-4:35Snowberry

HSTeaching 8:30-1:00LakeLoveland

Analytical 8:30-10:15RiverBirchA

Biochemistry 8:30-11:10RiverBirchC

Inorganic 8:30-12:30RiverBirchB

1:30-5:30RiverBirchB

Organic 1:30-5:30RiverBirchB

8:30-12:30ApenDaisy

Physical 1:30-4:10RiverBirchC

WelcomeReception/PosterSession

6:00-8:00PinyonPine

AnalyticalPoster 1:30-3:30PinyonPine

BiochemPoster 10:30-12:30PinyonPine

OrganicPoster 3:30-5:00PinyonPine

InorganicPoster 8:30-10:30PinyonPine10:30-12:30PinyonPine

PhysicalPoster 10:30-12:30PinyonPine

ChemEdPoster 8:30-10:30PinyonPine

Exposition 6:00-9:00PinyonPine

8:30-12:30PinyonPIne

1:30-5:30PinyonPIne

8:30-12:30PinyonPine

UGProgram 6:00-9:00BigThompson

8:30-12:30BigThompson




CareerWrkshp 8:30-12:30LakeLoveland

1:30-5:30LakeLoveland

Governance 2:30-3:30Goldenglow

YCCLunchWCCBreakfastSCCBreak

7:30-8:30WCC10:00-11:00SCCLakeLoveland

12:00-1:30YCCLakeLoveland

AwardsBanquet 6:00-9:00LakeLoveland

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2017 RMRM Event Schedule Richard Schwenz, Program Chair

WEDNESDAY EVENING

Sci-Mix Embassy Suites & Conference Center Pinyon Pine R. W. Schwenz, Organizer

6:00pm - 8:00pm

12, 18, 55, 60, 68, 72, 74, 76, 83, 128, 133, 137, 153, 154, 186, 190, 198. See subsequent listings.

THURSDAY MORNING

Catalysts & Green Chemistry Embassy Suites & Conference Center Elderberry H. Zhao, Organizer, Presiding

8:30 1. Catalysis for sustainable “green” polymers with robust properties and complete recyclability. E.Y. Chen

9:00 2. Ionic liquids as alternative and morphology-steering media for nanoscale growth. G.A. Baker, D. Wagle, N. Bhawawet, L. Adhikari

9:30 3. Strongly reducing visible light organic photoredox catalysts. G. Miyake

10:00 4. New methods to functionalize electron-deficient aromatic heterocycles and pharmaceuticals. A. McNally

10:30 Intermission.

10:45 5. Organocatalytic radical strategies for aldehyde synthesis. W. Wang

11:15 6. Gearing sustainable transition metals for solving problems in organic synthesis. R. Giri

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Inorganic Chemistry General Posters Embassy Suites & Conference Center Pinyon Pine R. W. Schwenz, Organizer

8:30am - 10:30am

7. Formulation of vanadium compounds in various supplements. A. Haase, D.C. Crans, L. Yang, X. Yang

8. Synthetic strategies for the development of dielectric Mie resonance based metamaterials. J. Abourahma, B.J. Burnett

9. Vanadium-dependent haloperoxidase enzymes: Using datamining to understand the coordination chemistry and mechanism of catalysis. H.A. Murakami, C.A. Wallace, D.C. Crans, C.C. McLauchlan

10. Synthesis and characterization of new photoactive and solvatochromic retinoid/carotenoid-based complexes of rhenium (I). A.J. Cruz, A. Depew, S. Bae, M. Carman, A. Richter

11. Cytotoxicity of nanoparticles on Rat alveolar macrophages. A. Arnold, C. Carter, D. Decker, A. Asunskis, D. Asunskis

12. Role of citrate in the stabilization and regulation of delivery of Ti(IV) bound serum transferrin. M. Julin, A.D. Tinoco

13. Kinetics and mechanism of permanganate oxidation of mandelic acid: Role of manganese intermediates, reactivity and product studies. S.N. Mahapatro, K. Sorauf, D. Mishra

14. Selenium uptake by the bryophyte Hygrohypnum ochraceum in the Fountain Creek Watershed correlates with dissolved iron: a case for speciation analysis. J. Carsella, D.C. Crans, I. Sanchez Lombardo, S.J. Bonetti

15. Co(II)-bis-terpyridine complexes for naked eye aqueous cyanide ion detection. C. Collins, J. Maughan, I. Bhowmick

16. Synthesis and characterization of tripodal copper catalysts for solar fuel production. T.B. Donadt, A.M. Lilio, T.H. Myren, O.R. Luca

17. Processing of lead iodide perovskite thin films for solar cell applications. H. Barton, B.J. Burnett

18. Study of electrocatalytic carboxylic acid reduction by Mn(4,4’-di-tert-butyl-2,2’-dipyridyl)(CO)3Br. A.M. Lilio, O.R. Luca

19. Multidentate macrocyclic ligands and their transition metal complexes: Synthesis, characterization, and CO2 reduction activity. A.M. Lilio, O.R. Luca

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Nanomaterials Embassy Suites & Conference Center River Birch C J. Zhou, Organizer J. Sambur, Presiding

8:30 20. Single nanosheet photocurrent microscopy of ultrathin liquid junction photovoltaics. J. Sambur

9:10 21. Electronic properties of solar cell materials studied by scanning tunneling microscopy. T. Chien

9:50 22. Chemistry on the surface of nanoparticles: Size-selected and single nanoparticle studies. S.L. Anderson, B.A. Long, E.T. Baxter, T. Gorey, D.J. Rodriguez, A.C. Cass

10:30 Intermission.

10:50 23. Nanostructured materials with unique catalytic properties. R.M. Richards

11:30 24. Multi-scale characterization of nanowire-based electrocatalysts. S. Pylypenko

Radioanalytical Nuclear Chemistry Embassy Suites & Conference Center River Birch B N. Xu, Organizer, Presiding

8:30 Introductory Remarks.

8:35 25. Coordination chemistry of +3 actinides. S.A. Kozimor

9:20 26. Fission track analysis for quantitation and mapping of complex fissile samples. V.L. Premo, M.P. Jensen

9:40 27. Rapid separations of fission products from uranuim-based target materials. J.M. Dorhout, K. Czerwinski

10:00 28. Developing an accurate algorithm to predict post-detonation urban debris composition. J. Auxier, J.D. Auxier, H.L. Hall

10:20 Intermission.

10:40 29. Analytical characterization of americium using radiometric techniques. J. Rim, D.R. Porterfield, D.J. Klundt, L. Tandon

11:00 30. Making americium hexavalent again. J. Braley, K. McCann

11:20 31. Analytical development of isotope dilution–high performance liquid chromatography–inductively coupled plasma–mass spectrometry (ID-HPLC-ICP-MS) for trace rare-earth quantification in a uranium matrix. E.M. Wylie, B.T. Manard, N. Xu, L. Tandon

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11:40 32. Bis-(2-ethylhexyl) phosphoric acid impregnated ordered mesoporous carbons for the separation of rare earth elements. E.R. Bertelsen, K. Kluherz, G. Deodhar, M. Adams, M.R. Davidson, B.G. Trewyn, J. Shafer

The Future of Chemical Education Embassy Suites & Conference Center Goldenglow J. P. Suits, Organizer, Presiding


8:35 33. Implementation of Next Generation Science Standards in high schools: Exploratory study. A. Pierce, C.E. Brown

8:55 34. Changes in the teaching and assessment of physical chemistry. R.W. Schwenz

9:15 35. Development of a computational educational laboratory activity to improve students' thinking skills and mental models for understanding intermolecular forces concepts. K.H. Tekletsadik

9:35 Intermission.

9:50 36. Development of a conceptual framework for second semester general chemistry. J.P. Suits

10:10 37. Flow state experiences in chemistry. K. Kemats, J.P. Suits

10:30 38. Math-Up Skills Test (MUST) as a predictor of success in general chemistry. B. Mamiya, A. Chen, D.S. Mason

10:50 39. Correlation between different online homework systems, student success, and knowledge decay. B. Mamiya, D.S. Mason

11:10 40. Six years of steady general chemistry improvement: Results from the program at the University of Utah. C.H. Atwood, B. Casselman, B. Ohlsen

Young Scholars Symposium Embassy Suites & Conference Center Snowberry D. C. Crans, Organizer, Presiding S. J. Bonetti, K. Chen, Presiding


8:35 41. Towards understanding the radical-S-adenosylmethionine protein MftC, a key compenent in mycofactocin biosynthesis.. J.A. Latham

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8:55 42. Does saturation of the isoprenyl side-chain in simple menaquinone analogs, MK-1 and MK-1 (H2), alter folded conformations and redox potentials? J.T. Koehn, C. Beuning, B. Peters, S.K. Dellinger, C. Van Cleave, L. Yang, D. Crick, D.C. Crans

9:15 43. Structural and electronic consequences of [Cp*] ligand protonation. J.D. Blakemore

9:35 Intermission.

9:55 44. Development of new reactions utilizing ynol ethers. B.W. Michel

10:15 45. Unequal spin delocalization in allyl and benzyl radicals: conjugation and hyperconjugation effects probed by chemical computations. D.J. Van Hoomissen, S. Vyas

10:35 46. 1,2-Fluorine radical rearrangements probed by theoretical means. D.J. Van Hoomissen, S. Vyas

10:55 47. Reversal of hydrolytic reactivity of organic molecules: Schiff-bases in reverse micelles. K. Hassell

11:15 48. Selective functionalization of pyridines and diazines via heterocyclic phosphonium salts. A. McNally

Inorganic Chemistry General Posters Embassy Suites & Conference Center Pinyon Pine R. W. Schwenz, Organizer

10:30 - 12:30

49. Synthesis of 1,3,6-trisubstituted fulvene coordination complexes as versatile building blocks for functional materials. N. Williams, S.K. Adas, G.J. Balaich

50. Growth of gold-silver core-shell nanoparticles. A. Ethridge, M. Watzky

51. Investigation of a tripodal nickel catalyst for CO2 reduction and hydrogen production. T.H. Myren, A.M. Lilio, T.A. Stinson, T.B. Donadt, O.R. Luca

52. Improvement of transition metal carbide catalyst by tuning nitrogen content in the carbon shell. D. Harris

53. Carbon–hydrogen bond activation with Tp*MoO(X)Y (X = O, S; Y = Cl, OPh) as a model for xanthine oxidase. D. Clair II, M. Ortega-Keshmiri, M.A. Cranswick

54. Characterization of the hydrolysis of select vanadium(V) catecholate complexes and their interaction with a model membrane system. S. Petry, J.T. Koehn, C. Glover, A. Levina, P.A. Lay, D.C. Crans

55. Borate-carbohydrate interactions in the synthesis of novel carbon materials, biofuels and chemical feedstocks. D.M. Schubert, M.B. Jacobs

56. Synthesis and characterization of 1,3-diphenyl-6-aryl/alkyl fulvene chromium complexes. M. Smith, A. Peloquin, B. O'Connell, S.K. Adas, G.J. Balaich, S.T. Iacono

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57. Efforts toward spin state changes in Fe(II) coordination complexes through post-assembly conformational switches. B. Livesay, M.P. Shores

58. Development of chiral main group metal complexes for atom transfer catalysis. T.B. Donadt, T.A. Stinson, A.M. Lilio, O.R. Luca

59. Probing the kinetics of formation of silver nanoparticles prepared via a modified Turkevich method. H. Sandoe, S. Diaz, M. Watzky

60. Synthesis of novel tripodal CMPO ligands for extraction of lanthanides and actinides in nuclear recycling and remediation. M.L. Hudson, B. Wackerle, S.M. Biros, E.J. Werner

Physical Chemistry General Posters Embassy Suites & Conference Center Pinyon Pine R. W. Schwenz, Organizer

10:30 - 12:30

61. Single particle electrochromics. R.C. Evans, J. Sambur

62. Shape-controlled Ce-doped LaNiO3 perovskite as precursors for dry reforming of methane catalysts. Y. Zou, J. Lopez, J. Zhou

63. Application and challenges of physisorption characterization on mudrocks. N. Joewondo, M. Prasad

64. Condensed phase excitation energies database. N. Dubinets, L.V. Slipchenko

65. Photophysical properties of biological chromophores: Fluorescence quenching of cyanophenylalanine derivatives. S. Moonitz, B. Berthold, J.P. Martin

66. Solid alkane reverse micelles (SARMs) - sodium dynamics in the solid state. I. Sitarik

THURSDAY AFTERNOON

Biomaterials for Energy Production Embassy Suites & Conference Center River Birch A F. G. Baddour, Organizer R. M. Richards, Presiding

1:30 77. Fungal pretreatment to improve pyrolysis of lignocellulosic biomass. K. Stahlfeld, E. Belmont, K. Wawrousek

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2:00 78. Fatty acid production by an environmental microbe grown in an agricultural co-product stream. K. Stahlfeld, E. Belmont, K. Wawrousek

Energy Production from Solar Radiation Embassy Suites & Conference Center River Birch A C. A. Koval, Organizer R. M. Richards, Presiding

2:30 116. Solar-to-hydrogen efficiency: Shining light on photoelectrochemical device performance. J.L. Young, H. Doescher, J. Geisz, J.A. Turner, T.G. Deutsch

2:50 117. Case study: Seven years of solar energy data. D.W. Hendricks

3:10 118. Inverted metamorphic multijunction III-V semiconductors for solar hydrogen production. T.G. Deutsch, J.L. Young, M. Steiner, H. Döscher, J.A. Turner

3:30 119. Solar powered pyrolysis in fixed bed reactor. A. Rony, Z. Sun, Y. Zheng, M. Fan

Analytical Chemistry General Posters Embassy Suites & Conference Center Pinyon Pine R. W. Schwenz, Organizer

1:30 - 3:30

67. Analysis of the glycemic response and thermal properties of β-glucan substituted starches. A. Anderson

68. GC-MS Analysis of biodiesel components derived from the Soxhlet extraction of avocado endocarp and trituration of avocado mesocarp.. A.J. Cruz, A. Depew, M. Carman, S. Bae, B. Maricle

69. Biodiesel production: A quality analysis. J. Didelot, E. Millward, M.B. Jacobs, S. Ahsan

70. Determining kinetic data for the APEH and ACY pathway. C. Cole, D. Coffman, T. Covey, N. Drysdale

71. Measurement uncertainty budgets for certified spectrophotometer calibration filters. J. Crawford, M. Hartwell, D. Martinez, J. Messman

72. Initialization quality control of a higher-order transfer absorption spectrophotometer. D. Martinez, M. Hartwell, J. Crawford, J. Messman

73. Champion and spectator nanoflakes in mechanically exfoliated MoSe2 thin films identified by single nanoflake photoelectrochemical mapping. M.A. Todt, A. Isenberg, J. Sambur

74. Effect of platinization on sensitivity of commercial Pt microelectrodes. J. Staver, Z. Black, M.M. Reynolds

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75. Measurement evaluation of presumptive out-of-tolerance observations for spectrophotometer calibration filters. M. Hartwell, D. Martinez, J. Crawford, J. Messman

76. Characterizing dissolved organic matter in surface waters through excitation-emission fluorescence spectroscopy and parallel factor analysis. K.J. Sorauf, S. Pribil, R. Flores

Catalysts & Green Chemistry Embassy Suites & Conference Center Elderberry H. Zhao, Organizer, Presiding G. A. Baker, Presiding

1:30 79. Novel pyrylium ion and activated furan/pyrrole mediated cycloadditions. J.W. Herndon, Y. Yin, J. Hu, L.S. Gamage, B.T. Rose

2:00 80. From green process to green bioactive products. C.T. Chang

2:30 81. Enzymatic ring-opening polymerization (ROP) of lactides: Solvent effects and controlling factors. H. Zhao, G. Nathaniel, P. Merenini

3:00 Intermission.

3:15 82. Development of organic photoredox catalysts for organocatalyzed atom transfer radical polymerization. B. McCarthy, G. Miyake

3:45 83. Synthesis and incorporation of thiophene and benzothiophene groups to stabilize RNA structure. M.J. Resendiz, H. Wang, L. Sharp, J. Sturgell, D. Hernandez

4:15 84. Polymer electrolytes for sustainable power storage devices. C.C. Browder

Chemical Education Organic Chemistry Education Embassy Suites & Conference Center Goldenglow J. P. Suits, Organizer R. W. Schwenz, Presiding


1:35 85. Design of undergraduate organic laboratory project to introduce heteronuclear NMR of novel synthetic products. M. Saidov, S.M. Schelble

1:55 86. Tracing the changing content of organic chemistry. M.L. Druelinger, A.M. Schoffstall

2:15 87. Incorporating multi-week independent projects into the second semester organic chemistry laboratory: Challenges, successes, and lessons learned. N.C. Kallan

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2:35 88. “Where do your eyes go?” Using eye movement modeling examples as an instructional tool in organic chemistry – EYE-OC. M. Weinrich, N. Graulich, S. Bernholt

2:55 Intermission.

3:10 89. Investigating how organic chemistry students solve stereochemical problems. T. Knowles, J.P. Suits

3:30 90. Active learning and students‘ ability to transfer knowledge of organic chemistry to biochemistry. J. Chavez, C.E. Brown

3:50 91. Students’ misconceptions on the major metabolic pathways. A. Abdugadar, J.P. Suits

Nanomaterials Embassy Suites & Conference Center River Birch C J. Zhou, Organizer R. M. Richards, Presiding

1:30 92. Vacancy-ordered double perovskites: Molecule-like structures with band-like behavior. A. Nunn, J.R. Neilson

2:10 93. Sensitization of oxide single crystals with quantum confined semiconductors. B.A. Parkinson, L. Kubie, K. Watkins

2:50 94. Atomic layer etching using thermal reactions: Atomic layer deposition in reverse. S.M. George

3:30 Intermission.

3:50 95. Water nano-droplets containing simple lipid or peptide-additives: Exploring the properties and interactions of solutes with soft materials. D.C. Crans, J.T. Koehn, C. Beuning, B. Peters, K. Doucette, N. Knebel, C. van Cleave, D.C. Crick, M.D. Johnson

4:30 96. Doping of biologically produced magnetic nanoparticles. K. Wawrousek, J. Rex, M. Seas, P.A. Johnson

Organic Chemistry General Papers Embassy Suites & Conference Center River Birch B R. W. Schwenz, Organizer C. I. Muldoon, Presiding


1:35 97. Design of visible light organic photoredox catalysts for the synthesis of polymers and small molecules. C. Lim, G. Miyake

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1:55 98. Design, synthesis and application of highly reducing organic photoredox catalysts. R.M. Pearson, G. Miyake

2:15 99. Stereoselective synthesis of endoperoxide containing heterocycles. D.M. Rubush, T. Vavrek

2:35 100. Transition-metal free synthesis of photoredox catalysts for organocatalyzed atom transfer radical polymerization. M.D. Ryan, N. Garrison, G. Miyake

2:55 101. Synthesis of advanced polymeric architectures using organocatalyzed atom transfer radical polymerization. B. Buss

3:15 Intermission.

3:30 102. Solvent and substituent effects in the electrochemistry of aryldiazonium ions. S.N. Mahapatro, J.P. McEvoy, M. Fernandez

3:50 103. Lithium doped magnesium oxide catalyst for the OCM reaction. D. Isaak

4:10 104. Synthesis of candidate Natural Killer T cell ligands utilizing novel tandem Staudinger and aziridine formation reaction. T. Haynie, S. Deng, P. Savage

4:30 105. Synthesis of Staphylococcus aureus serotype 5 and serotype 8 linkers for self-adjuvanting vaccine. S.M. Mata, P. Savage

4:50 106. Transparent wood-based composites. K. Foster

5:10 107. Synthesis of pyridazinedione derivatives of triazole diesters. K.A. Stewart, A.M. Schoffstall

Young Scholars Symposium Embassy Suites & Conference Center Snowberry D. C. Crans, Organizer, Presiding L. J. Berliner, J. D. Blakemore, M. O'Connor, Presiding


1:35 108. Antagonistic cytotoxicity of the Cu(II) and Ti(IV) complexes of deferasirox illuminates the complexity of physiological metal speciation. A.D. Tinoco, S.A. Loza-Rosas, A. Zayas, A. Mendez

1:55 109. Coordination chemistry strategies to next generation quantum bits and EPR imaging agents. J. Zadrozny

2:15 110. Synthesis of α-Fe2O3 hollow spheres: photonic crystal mimics. A.M. Morey

2:35 111. Laser based chemical analysis technique for the characterization and mapping of uranium particles. B.T. Manard, E.M. Wylie, N. Xu

2:55 Intermission.

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3:15 112. Single-particle electrochemistry for solar energy conversion and smart windows. J.B. Sambur

3:35 113. Spectroscopic speciation studies on the Actinide Lanthanide SEParation process (ALSEP). G. Picayo, M.P. Jensen

3:55 114. Experimental probes of the formation of silver nanoparticles and gold-silver core-shell nanoparticles. M. Watzky

4:15 115. Reassociation of multisubunit proteins released from mesoporous silica nanoparticles with conserved enzymatic activity. B.G. Trewyn, G. Deodhar

Organic Chemistry General Posters Embassy Suites & Conference Center Pinyon Pine R. W. Schwenz, Organizer

3:30 - 5:00

120. Increasing efficiency of ethanol production from crude glycerol and Enterobacter aerogenes. A.M. Mayes, D.L. Dillon

121. Comparing novel metal-mediated routes to the synthesis of 3,5-disubstituted-2-isoxazolines. S.B. Schottler, E. Bodak, D. Wardle, M.D. Mosher

122. Catalyst-free direct electrochemical cross coupling reactions. A.M. Lilio, C.G. Martin, T.B. Donadt, O.R. Luca

123. Carbon isotope geochemistry of hydrocarbon gases in sandstone reservoirs in the Denver-Julesburg basin, northeastern Colorado. C.R. Nelson

124. Synthesis of a fluorescently-tagged bile acid to track transepithelial movement in the colon. H.S. Malik, E. Gornick, Y. Kim, U. Dinsmonaite, M. Haq, J. Sarathy, D.M. Rubush

125. Photocatalytic degradation of metoprolol: Reaction conditions, intermediates and total reaction mechanism. E. Leyva, E. Moctezuma, K.M. Baines, M. Lopez

126. Electrocatalytic methods for O-atom transfer reactions. T.A. Stinson, T.B. Donadt, C.G. Martin, O.R. Luca

127. pKa of humulone. J. Landon, M.D. Mosher

128. Progress toward the total synthesis of citrinalins A and B. K. Klas, K. Ikeuchi, R.M. Williams

129. Synthesis of biologically active 1,2,4-dioxazinanes via aza-Michael desymmetrization. T. Vavrek, D.M. Rubush

130. Scalable synthesis of antibiotic natural products: Progress toward the total synthesis of baulamycins A and B.. J.R. Thielman, R.M. Williams

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131. Synthesis of the Histone Deacetylase inhibitor Largazole and a complex library of analogs for therapeutic utility. C. Dunne, L. Zhao, R.M. Williams

132. Synthesis of photoredox catalysts for organocatalyzed atom transfer radical polymerization. N. Garrison

133. Isoxazoline compounds for inhibition of tryptophan biosynthesis. T. DePaola, J.M. Ellsworth, C.C. Browder

134. Synthesis of benzothiophene models for testing their photochemical reactivity within RNA. L. Sharp, D. Hernandez, J. Sturgell

135. Reactivity between cisplatin and 8-oxo-7,8-dihydroguanosine – The missing link between oxidative stress on RNA and chemotherapeutic agents.. A. Skinner, M.J. Resendiz

136. Investigations into the conjugate hydrocyanation of α,β-unsaturated aldehydes in organic synthesis. V. Nguyen, N.C. Kallan

137. Educational undergraduate synthesis of N-Methyl Prozac®, a precursor to the classic SSRI fluoxetine. R. Dohoney, S. Jensen, E. Millward, M. Dalton

138. Synthesis and characterization of a simple lipoquinone analog: Ubiquinone-2 adopts a folded conformation in solution and within a reverse micelle AOT-water interface. J.T. Koehn, J.W. Ives, D.C. Crick, D.C. Crans

FRIDAY MORNING

Analytical Chemistry General Papers Embassy Suites & Conference Center River Birch A R. W. Schwenz, Organizer D. L. Pringle, Presiding


8:35 139. Biennial study on two on-road heavy-duty California fleets' fuel specific emissions. M. Haugen, G. Bishop

8:55 140. Combining Excel and electronics: A new way for reviving instrumentation, adding capabilities, and making new analytical systems. S. Abbott

9:15 141. Getting the most from Excel in experimentation and instrumentation. S. Abbott

9:35 142. Does ingestion of the anticoagulant rodenticide Chlorophacinone make American kestrels “appear” older when estimating age based on pentosidine concentrations in skin samples? R.S. Stahl, C. Furcolow, K. Horak, B.A. Rattner

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9:55 143. Analysis of gas-phase mixtures of methane and propane by 1H NMR spectroscopy. J. Widegren, C. Suiter, T. Bruno

Biochemistry General Papers Embassy Suites & Conference Center River Birch C R. W. Schwenz, Organizer B. Mamiya, Presiding


8:35 144. Comparing the cooperativity of membrane insertion between C2AB tandem domains of synaptotagmin-7 and synaptotagmin-1. H.T. Tran, L. Anderson, J.D. Knight

8:55 145. Unravelling the role of tachykinin neuropeptides in copper homeostasis in the brain. L.J. Berliner, C. Jones

9:15 146. Supported Tubulated Bilayers (STuBs): an experimental platform for monitoring protein-mediated membrane remodeling. J.D. Knight, P. Dahl, N. Schenk, A. Ranski, M. Hanna, A. Audhya, A. Anantharam

9:35 147. Integration of antibacterial ionic liquids/deep eutectic solvents (IL/DES) into electrospun protein-based wound healing scaffolds. M.J. Harrison, T.A. Bardsley, P.D. Phillips, J.R. Greene, D. Fox, N.C. Nieto, R.E. Del Sesto, R.S. Keller, A.T. Koppisch

9:55 Intermission.

10:10 148. Divalent metal cation effects on the membrane binding of the Slp-2 C2A domain. T. Spotts, A. Watson-Siriboe, J.D. Knight

10:30 149. Calcium binding to C2B domains of Synaptotagmin 1, Synaptotagmin 7, and chimeric Synaptotagmin 1/7: A computational study. N. Chon, S. Tran, J.D. Knight, H. Lin

10:50 150. Investigations into the scope, efficacy and antimicrobial mechanism of the broad-spectrum antiseptic choline geranate deep eutectic solvent. J.R. Greene, K. Merrett, L.F. Simmons, A.J. Heyert, C.M. Migliori, R.S. Castro, M. Zakrewsky, S. Mitragotri, J.L. Baker, D. Fox, G.E. Lindberg, R.E. Del Sesto, A.T. Koppisch

11:10 151. Development of reversible thiol-ene bioconjugation for dynamic protein immobilization to hydrogels. J.C. Grim, K.S. Anseth

Chemical Education General Posters Embassy Suites & Conference Center Pinyon Pine

21

R. W. Schwenz, Organizer

8:30 - 10:30

152. Colorado State University – Pueblo’s Communities for Building Active Stem Engagement (CBASE) program and research communities. J. Manikoff, D.T. Conroy, A. Davidson, M.A. Cranswick

153. Get involved with the ACS Division of Chemical Education. M.A. Horn

154. NTS – New SI unit definitions. M.D. Mosher, R.A. Yokley, H.N. Cheng

155. Developing electrophilic fluorination experiments for the undergraduate organic chemistry laboratory. J. Garcia, M.L. Druelinger, D.L. Dillon

156. 3-D chemistry exercises utilizing Virtual Reality technology. B. Whaley, A. Sweitzer, R.M. Hyslop, C.E. Brown

157. Development of a rubric to facilitate improvement in students’ molecular mechanisms in chemistry research papers. A.C. Millar, K.J. Knaus

158. Systematic approach to teaching NMR analysis in undergraduate organic laboratories. S. Jensen, J. Cook, C. Magee, S.M. Schelble

Inorganic Chemistry General Papers Embassy Suites & Conference Center River Birch B R. W. Schwenz, Organizer M. Watzky, Presiding


8:35 159. Lengthening Fe(II) MLCT excited-state lifetimes by accessing the high-spin manifold using a tunable ligand framework. S.M. Fatur, S.G. Shepard, N.H. Damrauer

8:55 160. Pd solubility in transition metal carbides for the methanol oxidation reaction. J.M. Thode, B.M. Leonard

9:15 161. Crystalline Co3O4 nanoparticle synthesis and the role of alcohol solvents: Evidence for a wholly kinetic, and not a surface ligand thermodynamic, alcohol solvent effect. S. Folkman, M. Zhou, M. Nicki, R.G. Finke

9:35 162. Exploring and mitigating failure modes in electrodeposited Cu-Sb anodes for Li-ion batteries. M. Schulze, A.L. Prieto

9:55 163. Analysis of bulk and surface properties of catalytically-active nickel carbide/nitride nanostructures using X-ray techniques. S. Gage, C. Ngo, S. Shulda, C. Tassone, D. Nordlund, S. Pylypenko, R.M. Richards

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10:15 Intermission.

10:30 164. Substituent effects on the HOMO-LUMO absorption and emission of Pt(II)-biphenyl complexes containing 1,10-phenanthroline derivatives. A.J. Cruz

10:50 165. Bulky β-diketones enable new Lewis acidic ligand platform. M.P. Marshak

11:10 166. Inorganic-organic hybrid material for the cyanide sensing using Co(II)-bis-terpyridine complexes. I. Bhowmick, C. Collins, J. Maughan

11:30 167. Hot injection synthesis and stacking of p-type solar absorbing Cu3SbSe3 nanodiscs. D. Agocs, A.L. Prieto

11:50 168. Comparison of the surface electrolyte interface from sodium and lithium ion batteries on copper antiminide electrodes. N.J. Gimble, A.L. Prieto

12:10 169. Developing a solution phase synthetic route to Cu2SiSe3: An earth abundent photovoltaic material. L.J. Moloney, A.L. Prieto

Organic Chemistry General Papers Embassy Suites & Conference Center Aspen Daisy R. W. Schwenz, Organizer A. L. Carlson, Presiding


8:35 170. Organic-inorganic nano hybrid catalyst for slurry phase residue hydrocracking. R. Prajapati

8:55 171. Selective β C-H mono- and di- halogenation of alcohols via radical relay chaperones. A. Vanitcha

9:15 172. Spectroscopic properties of imidazolium based room temperature ionic liquids. B.D. Etz, N. Losada, T. Schutt, S. Vyas

9:35 173. Synthesis of sialyl-Tn (STn) antigens for the development of efficient cancer vaccine. P. Khanal, P. Savage

9:55 174. Using chemical principles to imitate and interface with biological systems. D. Domaille

10:15 175. Catalytic hydroxylation of polyethylenes. A. Bunescu, S. Lee, Q. Li, J.F. Hartwig

10:35 Intermission.

10:50 176. Synthesis and computational analysis of configurationally stable dual domain twistacenes. J.A. Weber, E.L. Clennan

11:10 177. Nitration and reduction of pyrazines. A.T. McGrath, A.M. Schoffstall

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11:30 178. Visible-light promoted C-S bond formation via intermolecular charge-transfer. B. Liu, C. Lim, G. Miyake

11:50 179. 3D printing polymeric photonic crystals. B. Boyle, G. Miyake

12:10 180. Photoinduced organocatalyzed atom transfer radical polymerization using continuous flow reactors. L.R. Beck, G. Miyake

Chemistry & the Environment Embassy Suites & Conference Center River Birch A R. W. Schwenz, Organizer M. Weinrich, Presiding

10:15 181. Monitoring Volatile Organic Compounds (VOCs) in real-time on oil and natural gas production sites. R.C. Lupardus, S. Franklin, D.L. Pringle

10:35 182. Biogeochemical and microbial dynamics of produced water from unconventional wells in the Powder River Basin, Wyoming. D.L. Drogos, K. Wawrousek, M. Urynowicz, C.W. Nye, S.A. Quillinan

10:55 183. Microbial community analysis of produced waters from the Green River Basin in Wyoming. K. Wawrousek, D.L. Drogos, M. Urynowicz, C.W. Nye, S.A. Quillinan

Biochemistry General Posters Embassy Suites & Conference Center Pinyon Pine R. W. Schwenz, Organizer

10:30 - 12:30

184. Probing the specific interactions of simple aromatic amides with a reverse micellar interface. B. Peters, D.C. Crans, D. Crick, G. Cardiff

185. Investigating the effects of pyrazinamide and pyrazinoic acid on model membranes. C. Van Cleave, J. Hough, B. Peters, A. Haase, D. Crick, D.C. Crans

186. Characterization of chitinase activities in copper supplemented Penicillium spinulosum cultures. B.J. Trujillo, S.J. Bonetti

187. Synthesis of a fully saturated menaquinone analog, menaquinone-2 (I,II-H2) and investigation of its interaction with a reverse micelle model membrane interface. E.A. Gubler, J.T. Koehn, D.C. Crick, D.C. Crans

188. Monitoring pH collapse across a bilayer: Modeling the mechanism of action of the anti-tuberculosis drug pyrazinamide. L.L. Henry, K. Doucette, D.C. Crans

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189. Synthesis and in Vitro metabolism of cannibidiol dimethyl ether. T. Cale, R.M. Hyslop, S. Bydalek

190. UHPLC isolation of tartrate-resistant acid phosphatases from Penicillium spinulosum. B.A. Schofield, S.J. Bonetti, J. Carsella

191. Molecular mechanism of cancer inhibition: Cannibinoids as anti-cancer agents. J.A. Folsom, N.A. Pullen, C.E. Brown, R.M. Hyslop

192. Inflammatory responses of mast cells with cannabidiol and tetrahydrocannabinol. C.R. Laster, D. Lyons, N.A. Pullen, C.E. Brown, R.M. Hyslop

193. Transparent titanium dioxide nanotubes: Development, characterization, and application in establishing cellular response mechanisms. J. Meyerink, G. Crawford

194. Determining the enzymatic degradation of RNA containing 8-oxo-7,8 dihydroguanine or 8-oxo-7,8-dihydroadenine. C. Herbert, M.J. Resendiz

195. Cellular toxicity associated with triterpene production in an Escherichia coli heterologous host. D.C. Thomas, P.P. Savani, D. Fox, B.A. Pfeifer, R.E. Del Sesto, A.T. Koppisch

196. Investigating the mycofactocin biosynthetic pathway. R.S. Ayikpoe

197. Formation of protein coronas on metallic nanoparticles and removal of metallic cores. E. Davidjuk, S.M. Reed, D. Hamilton

198. Investigating the antidiabetic effects of metformin on pyruvate carboxylase. G. Solis, S. Bydalek, C.E. Brown, R.M. Hyslop

199. Analysis of organic and inorganic compound in tattoo ink. C. Hansen, R.M. Hyslop, C.E. Brown

FRIDAY AFTERNOON

Chemistry of Beer & Brewing Products Embassy Suites & Conference Center River Birch A M. D. Mosher, Organizer, Presiding


1:35 200. Brewing flavor chemistry: Analytical challenges and opportunities. D.L. Sedin

2:05 201. Mousey off flavor in beer: Origins and control. L. Barr

2:35 202. Art & mystery of malting: A simple man's view. M. Stuart

3:05 203. DMS formation by lager yeast strains – A possible role for mitochondria. E. Samp

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3:35 Intermission.

4:05 204. Application of metabolomics to understand the chemistry of flavor and flavor stability in beer. A. Heuberger, H. Bettenhausen, L. Barr, C. Broeckling, C. Holbrook, J. Prenni, D.L. Sedin

4:35 205. Observing humulone isomerization by polarimetry. S.E. Johnson, M.D. Mosher

5:05 206. CO2 analysis in decarboxylation reactions throughout fermentation. A. Campanella

Inhibitor Design & Studies in Medicinal Chemistry Embassy Suites & Conference Center Aspen Daisy D. C. Crans, Organizer C. C. McLauchlan, V. L. Pecoraro, Presiding


1:45 207. Development of dendrimeric metallacrowns. V.L. Pecoraro, B. Lopez-Bermudez, S. Eliseeva, S. Petoud

2:20 208. Cytotoxic titanium(IV) compounds prepared with iron chelators attenuate the bioavailability of the intracellular labile iron pool. A.D. Tinoco, S.A. Loza-Rosas, A.M. Vazquez, K. Gaur, S.C. Perez, E. Tomat, E.A. Akam, A.V. Astashkin, M. Saxena, S. Sharma, N. Noinaj, Y. Delgado, K.I. Rivero, L. Negron, T.B. Parks, J. Benjamin, Y.M. Cruz, A.L. Vazquez

2:55 209. Pyrazinoic acid: Using mechanistic modelling to unravel the origin of pyrazinamide's synergy with other tuberculosis drugs. D.C. Crick, F. Fontes, S. Rooker, B. Peters, D.C. Crans, M.A. Lyons

3:30 Intermission.

3:45 210. Relationships between plasma metal ions and the development of infectious diseases in health and disease. P.L. Carver

4:20 211. Investigations into the ideal coordination geometries of vanadium-based enzyme inhibitors. C.C. McLauchlan, C.A. Wallace, M. Tarlton, D.C. Crans

4:55 212. Vanadium compounds as synergetic agents in oncolytic virotherapy. D.C. Crans, M. Selman, J. Diallo

Inorganic Chemistry General Papers Embassy Suites & Conference Center River Birch B R. W. Schwenz, Organizer M. Watzky, Presiding


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1:35 213. Synthesis and characterization of lithium doped magnesium oxide (111) catalysts for the oxidative coupling of methane. A.M. York, D. Isaak, R.M. Richards, B.G. Trewyn

1:55 214. Development of a novel selective synthesis of solid ionically conductive materials through electrochemical corrosion. J.D. Schneider, J. Ma, A.L. Prieto, J.R. Neilson

2:15 215. Development of a nanocrystal synthesis of copper phosphorus selenide (Cu3PSe4): Investigation into an overlooked material for PV applications. J. Lee, A.L. Prieto

2:35 216. Mechanistic studies into Cr-catalyzed photoredox reactions. R. Higgins

2:55 217. Synthetic surface studies of iron sulfide nanocrystals. R.C. Miller, A.L. Prieto

3:15 Intermission.

3:30 218. Impurity phase effects on the electrochemical performance of electrodeposited SnSb. J. Ma, A.L. Prieto

3:50 219. Voltage dependent solid electrolyte interface formation on copper antimonide anodes for lithium-ion batteries. L.A. Kraynak, A.L. Prieto

4:10 220. 1,3,6-Trisubstituted fulvene derived ansa-metallocene ligands: entry to bridged Eu(II) ansa-metallocenes. S.K. Adas, G.J. Balaich

4:30 221. Theoretical treatment of spin crossover behavior in Fe(II) complexes with iminopyridine ligands. J.P. Joyce, M.P. Shores, A.K. Rappe, T. Ozumerzifon

4:50 222. Utilizing mixed-linker zirconium based metal-organic frameworks to enhance the visible light photocatalytic oxidation of alcohol. T. Goh

5:10 223. Investigations into the electronic structure of coordinated ligands pertinent to Cr-photocatalysis. R.I. Portillo, M.P. Shores

Physical Chemistry General Papers Embassy Suites & Conference Center River Birch C R. W. Schwenz, Organizer, Presiding


1:35 224. Investigating the role of gas-surface interactions in NxOy plasma surface modification of zeolite materials. A.R. Hanna, E.R. Fisher

1:55 225. High-pressure response of optical and structural properties in CsPbBr3 and CsPbI3 perovskite nanocrystals. J.C. Beimborn, P. Tongying, L. Hall, M. Lusk, G. Dukovic, J.M. Weber

2:15 226. Highly excited states of chlorine substituted cumulenenone series. Q.L. Nguyen, W.K. Peters, M.M. Murnane, H. Kapteyn, R.C. Fortenberry

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2:35 227. Elucidating energy partitioning trends in hydrocarbon plasmas for plasma-assisted catalysis. T.L. Van Surksum, E.R. Fisher

2:55 Intermission.

3:10 228. Meuller tensor framework for second harmonic generation of unpolarized light. F. Deng, C. Ding, J.R. Ulcickas, G.J. Simpson

3:30 229. Non-equilibrium dynamics of chloride transport through the E. coli Cl–/H+ antiporter. C. Wang, A.W. Duster, M.G. Zarecki, H. Lin

3:50 230. Developing protocol for probing solvation energies of ALSEP extractants. A. Ta, G. Hegde, B.D. Etz, S. Vyas

SATURDAY MORNING

High School Teacher’s Symposium Pre-College Teachers Day Embassy Suites & Conference Center Lake Loveland A, B G. Glugoski-Sharp, E. Grow, Organizers, Presiding


8:30 231. Why Join CCTA and AACT? E. Grow

8:50 232. Adolescent marijuana use and health effects. D.I. Vigil

9:40 233. Scientific approaches to the testing and regulation of cannabis in Colorado. J. Bramante

10:20 234. Renaissance of Cannabis sativa L.as food, fiber and medicine in the United States. C. Kershner

11:00 235. Marijuana in the emergency department a doctors perspective. G. Glugoski-Sharp

11:40 236. How to manage and dispose of waste from K-12 science laboratories. M. O'Connor

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Abstracts

RMRM 1

Catalysis for sustainable “green” polymers with robust properties and complete recyclability

Eugene Y. Chen, [email protected]. Colorado State University, Fort Collins, Colorado, United States

The current practices in the generation and disposal of synthetic polymers are largely unsustainable. Several solutions have been intensively pursued to address this global challenge but the current solutions suffer from either significant materials value and quality losses or unintended environmental consequences. A proposed more sustainable solution is to develop chemically recyclable polymers that can not only solve the end-of-life issue of polymers but also provide a direct approach to establish a circular materials economy. However, a key challenge here is that polymers that can be depolymerized back to the building block monomers in high yield and selectivity are still rare, and polymers that are easily degradable or depolymerizable usually do not have the physical integrity and mechanical strength to be practically useful. In this context, this presentation will describe our recent and on-going efforts to develop catalytic methods and processes for the design and synthesis of next-generation sustainable polymers that not only exhibit robust physical and mechanical properties but can also be thermally and/or chemically depolymerized back to their monomers in quantitative yield and high purity, ready for reuse.

RMRM 2

Ionic liquids as alternative and morphology-steering media for nanoscale growth

Gary A. Baker, [email protected], Durgesh Wagle, Nakara Bhawawet, Laxmi Adhikari. Chemistry, University of Missouri-Columbia, Columbia, Missouri, United States

Ionic liquids possess immense flexibility in terms of the number of possible cation−anion combinations, as well as prospects for incorporating arbitrary functional ions (e.g., metal-chelating, redox-active, paramagnetic), suggesting a yet-unrealized potential for unprecedented control over nanoscale growth. However, in spite of this enormous potential, a vast knowledge gap exists in the mechanistic understanding of nanoscale growth and colloidal stabilization when utilizing these designer solvents. In this contribution, we will present recent results from our laboratories where we explore the potential of ionic liquids as low-volatility, tunable media for performing nanosynthesis. In one example, the coordinating strength of the ionic liquid anion is shown to exert control over the gold morphology generated at an aqueous/organic liquid interface. Another example entails the development of a facile, single-pot "iono-polyol" synthesis of single-crystalline magnetite (Fe3O4) nanoparticles via thermal decomposition of iron(III)acetylacetonate in a thermally-stable phosphonium ionic liquid. The information garnered in these studies will contribute to the development of expedient approaches targeting morphology-controlled and colloidally-stable nanoscale materials, as well as shedding light on the facility for ionic liquid recycle and reuse in nanosynthesis.

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RMRM 3

Strongly reducing visible light organic photoredox catalysts

Garret Miyake, [email protected]. Colorado State University, Fort Collins, Colorado, United States

Catalyst design principles of strongly reducing visible light organic photoredox catalysts and their application in the synthesis of polymers and small molecules will be presented.

RMRM 4

New methods to functionalize electron-deficient aromatic heterocycles and pharmaceuticals

Andrew McNally, [email protected]. Chemistry, Colorado State University, Fort Collins, Colorado, United States

Selective methods that can functionalize electron-deficient heterocycles are in great demand due to their prevalence in biologically active compounds. Pyridines and diazines, in particular, are widespread components of pharmaceutical compounds yet methods to transform these motifs into valuable derivatives are still greatly sought after. We will present a selection of catalytic and non-catalytic methods that enable multiple new bond-constructions on these heterocycles. Phosphorus intermediates are the key mechanistic platform that allows these new transformations to occur; in many cases, elongated synthetic sequences can be truncated into two steps thereby minimizing waste and increasing the pace of discovery. Simplicity and generality are a key feature of this approach making it immediately accessible to practitioners of chemistry.

RMRM 5

Organocatalytic radical strategies for aldehyde synthesis

Wei Wang, [email protected]. Univ of Nm Chem Dept, Albuquerque, New Mexico, United States

Arguably, aromatic aldehydes are the most fundamentally important substances used in organic synthesis. Therefore, the availability of predictable and chemoselective methods for aldehyde synthesis has a profound impact on chemical synthesis. Classical approaches to aromatic aldehydes are not atom- and step-economical. The state-of-the-art methods for the synthesis of aldehydes rely on transition metal catalyzed (hydro)formylation reactions. Achieving truly practical processes will streamline aldehyde synthesis, but require a fundamentally distinct design paradigm. Toward this end, recently our research laboratories initiated a program aimed at developing sustainable, environmentally friendly, and mild strategies for aldehyde synthesis. In this context,

30

new formylation reagents are designed and new reactivities are harnessed for developing unprecedented organocatalytic photoredox processes for efficient synthesis of structurally diverse aliphatic aldehydes, (hetero)aromatic aldehydes, and α, β-unsaturated aldehydes from feedstock chemicals.

RMRM 6

Gearing sustainable transition metals for solving problems in organic synthesis

Ramesh Giri, [email protected]. Chemistry & Chemical Biology, The University of New Mexico, Albuquerque, New Mexico, United States

Sustainable transition metals such as Ni and Cu not only come with unique properties but also imitate many of the reactivities of noble metals like Pd. We are striving to use these metals to solve one of the challenges in organic synthesis – that is to construct two carbon-carbon bonds simultaneously across an unactivated olefin using cross-coupling as a bond-forming strategy. To make this process work, two of the most well-known transformations – direct cross-coupling and Heck reaction by b-hydride elimination need to be suppressed. In this talk, we will present our work towards this goal using Ni and Cu-catalysts along with an example with Pd to showcase what it's like working with Pd for these types of reactions. Their applications to natural product synthesis and drug-molecule diversification, and mechanistic hypothesis will also be presented along the way where applicable.

RMRM 7

Formulation of vanadium compounds in various supplements

Allison Haase1, [email protected], Debbie C. Crans2, Lining Yang1,3, Xiaogai Yang4. (1) Chemistry, Colorado State Univerity, Fort Collins, Colorado, United States (2) Colorado State University, Fort Collins, Colorado, United States (3) Pharmacy, Xi’an Medical University, Xi’an, Shaanxi, China (4) Chemical Biology, Peking University, Beijing, China

Vanadium compounds have been known to have beneficial therapeutic properties since the turn of the century, but it was not until 1965 when it was discovered that those effects could be extended to

31

treating cancer as well as having potential for treating diabetes. While there are little to no vanadium based drugs currently on the market, there is a variety of supplements available containing vanadium compounds. Vanadium based supplements are commonly used for bodybuilding, weight loss, and glucose control. These supplements were compared to determine the average dose, the form of vanadium, formulation of the supplement, possible effectiveness, and other common factors between supplements. Considering the potential for vanadium as an antidiabetic and use as a supplement, it is likely that consideration of formulation of the vanadium based compound will improve the efficacy of the supplement. Future development of vanadium-based drugs and supplements should include consideration of formulation at earlier stages of development, and these should be examined for effectiveness in human studies.

RMRM 8

Synthetic strategies for the development of dielectric Mie resonance based metamaterials

Jehad Abourahma, [email protected], Brandon J. Burnett. Chemistry, Weber State University, Ogden, Utah, United States

Dielectric Mie Resonance Based Metamaterials have been theorized to improve the efficiency of thermo-photovoltaic cells by bridging the gap between the material bandgap and the radiation source energy. Currently, only a few proof of concept reports of actual materials have been reported. We present two synthetic strategies for the development of these metamaterials and compare the merits of both strategies on their thermo-optical properties.

RMRM 9

Vanadium-dependent haloperoxidase enzymes: Using datamining to understand the coordination chemistry and mechanism of catalysis

Heide A. Murakami1, [email protected], Craig A. Wallace3, Debbie C. Crans1, Craig C. McLauchlan2. (1) Colorado State University, Fort Collins, Colorado, United States (2) Dept of Chemistry, Illinois State Univ, Normal, Illinois, United States (3) Illinois State University, Normal, Illinois, United States

A datamining study was carried out analyzing the vanadium-peroxo complexes structural diversity with the objective of comparing the coordination geometry in small molecules with the vanadium in the active site of the haloperoxidase. The vanadate-dependent haloperoxidases are known to catalyze two-electron oxidations of halides to halogenated organic compounds. The active site of proteins tends to favor five-coordinate vanadium in a trigonal bipyramidal geometry. The details in the mechanism of which the oxidation occurs has been debated and in the following we use data mining to investigate the coordination chemistry of small molecules and vanadium-peroxo complexes. Using the information on the X-ray structures of vanadium-haloperoxidases and the analysis of the datamining of five, six, and seven-coordinate peroxovanadium(V) compounds, we explored the role of the protein, how it is altered by the coordination geometry of the vanadium, and the impact of the protonation step.

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RMRM 10

Synthesis and characterization of new photoactive and solvatochromic retinoid/carotenoid-based complexes of rhenium (I)

Arvin J. Cruz1, [email protected], Alli Depew1,2, [email protected], Simwoo Bae1,2, Marisa Carman1,2, Amelia Richter1,2. (1) Chemistry, Fort Hays State University, Hays, Kansas, United States (2) Kansas Academy of Math and Sciences, Fort Hays State University, Hays, Kansas, United States

Two new inorganic-based photosensitizer dyes of rhenium(I) attached to retinoid/carotenoid ligands have been synthesized. All ligands were prepared via Knoevenagel condensation reactions of all-trans-retinal (1) and β-apo-8’-carotenal with cyanopyridyl. Electronic UV/Visible absorption spectroscopy show that these complexes absorb visible light efficiently. Absorption wavelengths are in the 450 nm to 600 nm range. Density Functional Theory (DFT) calculations reveal that the frontier molecular orbitals involved during absorption process occur from the HOMO (highest occupied molecular orbital) to low-energy LUMOs (lowest unoccupied molecular orbital) of the metal center (rhenium, Re). Theoretical treatments also show that these orbitals are located primarily on the polyene chain and the energy gap between them is consistent with the observed optical spectrum. These dyes serve as photosensitizers attached to CdSe nanoparticles in dye-senstized solar cells (DSSCs).

RMRM 11

Cytotoxicity of nanoparticles on Rat alveolar macrophages

Adrienne Arnold2, Cassandra Carter1, Donald Decker1, Amy Asunskis1, Daniel Asunskis1, [email protected]. (1) School of Natural Sciences, Black Hills State University, Spearfish, South Dakota, United States (2) University of Kentucky, Lexington, Kentucky, United States

Nanoparticles (NPs) have made their way into common consumer products, from TV screens to antimicrobial clothing. While the properties of many chemicals are well-characterized, a chemical often becomes more reactive when it is made into a nanoparticle. This means that NPs may have different biological effects than what would be expected from the current toxicological data on bulk materials. As NPs become more prevalent, the importance of understanding their effects on people and the environment increases. In this project, cadmium selenide and silver NPs were synthesized and introduced into rat lung macrophage cell cultures in order to study the cells’ response. LDH and MTS assays were used to monitor cell death and mitochondrial activity. Expression of the proteins TNF-α and IL-6, two important indicators of cell stress, were analyzed using ELISA kits.

RMRM 12

Role of citrate in the stabilization and regulation of delivery of Ti(IV) bound serum transferrin

Mara Julin1, [email protected], Arthur D. Tinoco2. (1) Chemistry, Syracuse University, Syracuse, New York, United States (2) Chemistry, University of Puerto Rico Rio Piedras, San Juan, Puerto Rico, United States

Titanium Ti(IV) is commonly used as a key component of orthopedic, dental, and other implants due to its corrosion resistance and overall biocompatibility. Titanium based complexes have also been of interest as potential anti-cancer agents due to their ability to produce cytotoxicity in vitro.

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However, their inability to perform well in clinical trials highlights the importance of better understanding the delivery and uptake of released Ti(IV) in serum. Although previous studies have shown that soluble Ti(IV) released in blood is 100% bound to the human serum transferrin protein (sTf), its biological function in serum and in cells is still unknown. Recently, the Tinoco group has determined that the small molecule, citrate, not only acts as a chelating agent that protects Ti(IV) from hydrolysis, but also acts as a synergistic anion to the metal-bound protein complex. Consequently, to better understand the stabilization and regulation of Ti(IV)-sTf delivery, the extent of citrate’s involvement needs to be further investigated. This research seeks to pinpoint the influence of citrate on Ti-bound serum transferrin by focusing on the differences when it is present and in its absence. The results of a spin dialysis equilibrium experiment show citrate’s relative low binding affinity for the protein complex, and how its binding is dependent on the surrounding citrate background concentration. A second dialysis experiment was conducted and found that hydrolyzed Ti bound sTf binds little to no citrate at physiological levels. Finally, a metal-uptake experiment, as well as a FITC probed Ti-citrate protein complex, were successfully prepared for providing additional insight to citrate’s involvement in the localization of Ti bound sTf in cancer cells.

RMRM 13

Kinetics and mechanism of permanganate oxidation of mandelic acid: Role of manganese intermediates, reactivity and product studies

Surendra N. Mahapatro, Kellen Sorauf, Disha Mishra, [email protected]. Chemistry, Regis

University, Denver, Colorado, United States

The permanganate oxidation of mandelic acid is inherently complex due to the interplay of several manganese intermediates as a function of pH. Manganese (VI) is a stoichiometric intermediate in alkaline pH, while a soluble manganese(IV) species is formed at pH 7. HPLC product analysis show that benzaldehyde and benzoylformic acid are the major products in acidic and alkaline medium respectively. Benzoic acid is a secondary product of oxidation of both benzaldehyde and benzoylformic acid. We will present kinetic and product analysis results.

RMRM 14

Selenium uptake by the bryophyte Hygrohypnum ochraceum in the Fountain Creek Watershed correlates with dissolved iron: a case for speciation analysis

Jim Carsella3, [email protected], Debbie C. Crans2, Irma Sanchez Lombardo2, Sandra J. Bonetti1, [email protected]. (1) Colorado State Univ Pueblo, Pueblo, Colorado, United States (2) Colorado State University, Fort Collins, Colorado, United States (3) Cell and Molecular Biology, Colorado State University, Pueblo West, Colorado, United States

Selenium (Se) is a micronutrient that can have a wide range of effects on animal life. Because some of these effects can be negative it is important to understand how Se is incorporated by plants and how this micronutrient moves into the food web. Furthermore, plant Se transport mechanisms are important for the environment and bioremediation efforts. Past research has shown the bryophyte Hygrohypnum ochraceum to be a heavy metal and

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Se accumulator. The condition under which Se is transported by H. ochraceum appears to be complex and highly dependent on several elemental species found in the water. This model organism was immersed in Se containing Fountain Creek water for 10 days at 14 sites in the fall and spring of 2008. Water samples were collected and characterized three times per site during the ten-day exposure. The water samples were split into dissolved and total fractions. The dissolved fractions were filtered through a 0.45mm syringe filter. The total fractions were not filtered. The plants were then collected from the sites, dried, digested and analyzed for metals by ICP- MS. Twenty-six metals and metalloids were monitored including calcium(Ca), magnesium(Mg), iron(Fe), lead(Pb), arsenic(As), Se, nickel(Ni), cobalt(Co), copper(Cu) and zinc(Zn). Analyses indicated that plant Se uptake was significant in sites between Colorado Springs and Pueblo in the spring. In the spring both the dissolved and total fractions contained Fe while only the total fraction contained Fe in the fall. The presence of dissolved available Fe showed a correlation (R2=0.84) with bryophyte uptake of Se. Plant Se uptake is complex and involves the dynamic interaction of several species of Se, Fe, Ca, and Mg.

RMRM 15

Co(II)-bis-terpyridine complexes for naked eye aqueous cyanide ion detection

Cameron Collins1, [email protected], Jennifer Maughan2, Indrani Bhowmick1. (1) Colorado State University Pueblo, Pueblo, Colorado, United States (2) CSU pueblo, Pueblo, Colorado, United States

Cyanide (CN-) is an extremely toxic anion and only a small amount is fatal for a living being. Our goal is to use 3D metal complexes to sense cyanide colorimetrically which could be more cost effective and environmentally friendly compared to similar organic sensors and techniques. Our research showed Co(II)-bis-terpyridine complexes could be used for the naked-eye detection of CN- in aqueous solution in 10-6 M level.[1] Analogous Co(II) complexes have been attempted to synthesis using the [4′-(4-Methylphenyl)-2,2′:6′,2′′]-terpyridine ligand and [4'-(para-phenylcarboxyl)-2,2':6'2''-terpyridine] and with a different Co(II) salts. Eventhough all this complexes are suitable for selective detection cyanide ions in water; we found the solubility of the Co(II)-bis-terpyridine complexes and the charge balancing ion significantly influences the detection limit and visible color change in presence of cyanide. We are focusing our research on the cobalt complexes of [4'-(para-phenylcarboxyl)-2,2':6'2''-terpyridine] ligand in order to bind it on the cellulose surface and provide better portability to the sensor material.

RMRM 16

Synthesis and characterization of tripodal copper catalysts for solar fuel production

Trevor B. Donadt, [email protected], Alyssia M. Lilio, Tessa H. Myren, Oana R. Luca. Department of Chemistry and Biochemistry, University of Colorado Boulder, Broomfield, Colorado, United States

The correlation between increasing atmospheric carbon dioxide levels and climate change has motivated research into alternative fuel sources that can replace traditional fossil fuels. Our efforts are focused on catalytic electrochemical reduction of carbon dioxide in the presence of protons to

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generate a chemical fuel by storing proton and electron equivalents within the molecular framework of CO2. The present details our efforts towards the synthesis and characterization of two tripodal copper catalysts as candidates for CO2 reduction: [Cu(R3TREN)][(NO3)2] and [Cu(Tris(2-benzimidazolylmethyl)amine)][BF4]. These compounds feature an earth-abundant metal center and a ligand framework capable of energetically-favorable interactions with CO2 that can lower the overpotential for the reduction process. In this work, we report the synthesis and characterization of these C3-symmetric compounds and an assessment of their ability to catalyze the conversion of CO2 and protons to chemical fuels.

RMRM 17

Processing of lead iodide perovskite thin films for solar cell applications

Heather Barton1, [email protected], Brandon J. Burnett2. (1) Chemistry, Weber State University, Layton, Utah, United States (2) Chemistry, Weber State University, Ogden, Utah, United States

We present two process methods for the construction of high purity, polycrystalline lead iodide perovskite films – dip method and chemical vapor deposition method. Furthermore, we compare the merits of both types of thin film processes including product purity, process cost, environmental impacts, and time commitment.

RMRM 18

Study of electrocatalytic carboxylic acid reduction by Mn(4,4’-di-tert-butyl-2,2’-dipyridyl)(CO)3Br

Alyssia M. Lilio, [email protected], Oana R. Luca. Chemistry and Biochemistry , University of Colorado Boulder, Boulder, Colorado, United States

A previously reported CO2 electroreduction catalyst, Mn(4,4’-di-tert-butyl-2,2’-dipyridyl)(CO)3Br, has been utilized as a competent catalyst for the electrochemical reduction of carboxylic acids. Under an atmosphere of nitrogen, the complex shows two irreversible one-electron reduction waves. As increasing increments of phenylacetic acids are added, an increase in current at both reduction peaks can be seen with the enhancement at the second reduction catalytic wave being significantly larger. Suitable substrates, product distributions and reaction optimizations are discussed herein.

RMRM 19

Multidentate macrocyclic ligands and their transition metal complexes: Synthesis, characterization, and CO2 reduction activity

Alyssia M. Lilio, [email protected], Oana R. Luca. Chemistry and Biochemistry , University of Colorado Boulder, Boulder, Colorado, United States

Though carbon dioxide has the potential to serve as an abundant C1 source for solar fuels and other value-added chemicals, most of the carbon dioxide reducing catalysts produce only simple 2e- reduction products (CO and HCOO-). There is substantial interest in developing catalysts that

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can take CO2 beyond its 2e- limitation and make C-C bonds. The focus of this work is the development of cryptand macrocyclic ligand frameworks that can position at least two metals in close proximity. Under reducing conditions, these loci may allow for the formation of C-C products in CO2 conversion. In this work, we report the synthesis and characterization of novel multinuclear polydentate macrocyclic ligands and their transition metal complexes. We also report on preliminary studies of their CO2 reduction activity.

RMRM 20

Single nanosheet photocurrent microscopy of ultrathin liquid junction photovoltaics

Justin Sambur, [email protected]. Chemistry, Colorado State University, Fort Collins, Colorado, United States

Semiconductor nanosheet photoelectrodes represent the ultimate miniaturization limit for lightweight and portable photovoltaics. One attractive approach to fabricate nanosheet thin film devices is to exfoliate semiconductor nanosheets from high quality bulk crystals. However, exfoliated nanosheets generally vary in size, shape, thickness, and distribution of surface defect sites. Conventional optical and electrical characterization techniques have been used to measure ensemble–average properties of nanosheet thin film devices, but they do not reveal critical size, shape, thickness and defect–dependent optoelectronic properties. Here we use a single-particle photoelectrochemical approach to correlate photocurrent collection efficiency with nanosheet thickness and surface structure at the single-nanosheet level. We mechanically exfoliated MoSe2 nanosheets from a bulk single crystal, deposited them onto an Sn:In2O3 (ITO) electrode, and measured the photocurrent collection efficiency of individual nanosheets in MoSe2|I−/I3−|Pt photoelectrochemical solar cells. The mechanical exfoliation approach allowed us to compare individual nanosheet photocurrent efficiency to the parent, bulk crystal. Ensemble-averaged measurements showed that the bulk electrode photocurrent efficiency was ~10 times larger than the nanosheet-coated electrode. Surprisingly, single nanosheet photocurrent measurements revealed that ~15% of exfoliated nanosheets exhibited photocurrent efficiency values that were nearly equivalent to the parent crystal. Photocurrent mapping also showed significant intra-nanosheet heterogeneity that could be attributed to surface structural defects. We will present preliminary microscopy results on the electrical, photoelectrochemical, spectroscopic, and structural properties of the champion nanosheet population.

RMRM 21

Electronic properties of solar cell materials studied by scanning tunneling microscopy

TeYu Chien, [email protected]. Physics and Astronomy, University of Wyoming, Laramie, Wyoming, United States

Photovoltaic solar cells (PVC) utilize the energy level differences in different materials to separate the charges of excitons. One of the major approaches to improve PVC performance is to play with the relationships of the conduction/valence band positions in the active materials as well as the Fermi levels of the electrodes in order to maximize the charge separation efficiency as well as the open-circuit voltage. These are achieved, typically, by changing the materials with desired band structures, doping the materials, changing the size of the quantum dots (in quantum-dot sensitized solar cells), or engineering the extra interfacial layer between the active layer and the electrodes. In

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this talk, I will share our recent scanning tunneling microscopy and spectroscopy (STM/S) data on various types of PVC materials, including examples in semiconducting quantum dots doped with Mn, P3HT/PCBM organic solar cells, and organometallic halide perovskite materials. I will also discuss how the above mentioned approached may change the local electronic properties of the materials and solar cell performance.

RMRM 22

Chemistry on the surface of nanoparticles: Size-selected and single nanoparticle studies

Scott L. Anderson, [email protected], Bryan A. Long, Eric T. Baxter, Timothy Gorey, Daniel J. Rodriguez, Ashley C. Cass. Univ of Utah, Salt Lake City, Utah, United States

The surface chemistry of sub-20 nm particles can be substantially different than that observed for bulk materials or for larger nanoparticles, due to differences in the availability of particular binding sites, and quantum confinement effects on electronic structure. Two approaches to probing size effects will be discussed. For very small particles, in the cluster size regime, it is practical to prepare atomically monodisperse beams of cluster ions, which we deposit on well characterized surfaces to prepare ensembles of identical size particles. The spectroscopy and catalytic chemistry of the supported clusters are studied by surface science and electrochemical techniques. Both electronic and geometric size effects on the catalytic activity of supported clusters are observed, revealing the factors that control the rate-limiting step in catalysis. In addition, the electronic size effects have important implications for spectroscopic studies of nanometer structures. For larger particles, with thousands-to-millions of atoms, the size selection approach becomes impractical, and the huge variety of possible structures makes it desireable to use single particle methods, to avoid averaging over the structures in an ensemble. We have developed a single particle trapping technique that allows chemistry and emission spectroscopy to be measured continuously for individual nanoparticles as they are heated and/or exposed to gaseous reactants. Oxidation and sublimation chemistry of carbon nanoparticles will be used to illustrate the method. The kinetics of surface reactions can be measured with high sensitivity by tracking the particle mass. By carrying out measurements on a series of particles, the effects of particle size and particle-to-particle heterogeneity are determined. A titration method allows the site distribution of individual particles to be measured, and correlated with reactivity.

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RMRM 23

Nanostructured materials with unique catalytic properties

Ryan M. Richards1,2, [email protected]. (1) Chemistry , Colorado School of Mines, Golden, Colorado, United States (2) National Renewable Energy Laboratory, Golden, Colorado, United States

The preparation of nanoscale materials is one of the most exciting areas of modern science and is at the forefront of the quest for a sustainable future. The field of nanotechnology has generated a great deal of interest primarily because on this size scale numerous new and potentially useful properties have been observed. These size dependent properties include melting point, specific heat, surface reactivities, catalytic, magnetic, and optical properties. In particular, the Richards’ group is working on new synthetic methods to control the size, shape and composition of nanoscale materials and applying them in systems integral to alternative energy technologies, pharmaceuticals, biomass upgrading, batteries, petrochemicals and environmental cleanup. Recently, the Richards’ research group has developed techniques to produce a number of new nanoscale materials that have demonstrated unique catalytic activities through controlled faceting as well as novel intercalation strategies. Here, an overview of the recent highlights regarding these materials will be presented as well as opportunities for future collaboration.

RMRM 24

Multi-scale characterization of nanowire-based electrocatalysts

Svitlana Pylypenko, [email protected]. Chemistry, Colorado School of Mines, Golden, Colorado, United States

Advancing our understanding of electrocatalytic materials is crucial for designing next-generation electrocatalysts and devices. This talk will discuss the development of nanowire-based extended surface catalysts for oxygen reduction in polymer electrolyte membrane fuel cells, demonstrating evolution of surface properties during electrocatalyst synthesis, electrode preparation, and device operation. Challenges associated with nanowire characterization will be highlighted, stressing the importance of multi-technique characterization at multiple length scales.

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RMRM 25

Coordination chemistry of +3 actinides

Stosh A. Kozimor, [email protected]. Los Alamos Natl Lab, Los Alamos, New Mexico, United States

Actinides in the +3 oxidation state occupy central roles in many areas that are important for our quality of life. These range from developing targeted alpha therapy in treating cancer to processing spent nuclear fuel. Hence, there is pressing need to advance fundamental understanding of +3 actinide coordination chemistry. While numerous heroic efforts have advanced An (III) chemistry, two main technical challenges have impeded scientific advancements. These include (1) obtaining sufficient quantities of highly radioactive actinides for study, and (2) safely handling the highly-radioactive actinide elements. This talk will describe our recent efforts to make use of upgrades at the SSRL synchrotron facility to overcome the challenges associated with conducted studies on Ac, Am, and Cm elements.

RMRM 26

Fission track analysis for quantitation and mapping of complex fissile samples

Virginia L. Premo2, [email protected], Mark P. Jensen1,3. (2) Department of Chemistry, Colorado School of Mines, Golden, Colorado, United States (3) Nuclear Science and Engineering Program, Colorado School of Mines, Golden, Colorado, United States

Fission track analysis (FTA) is a method for detecting fissile material in wide range of samples. FTA images the path that fission fragments take by recording that path in a solid state nuclear track detector (SSNTD). After chemical etching, the fission tracks can be viewed by transmitted light microscopy with each track seen in the detector representing one fission event. We have been refining FTA to obtain more information from more complex samples, particularly in reference to plutonium (Pu). Using the 3D trajectory of the fission fragments into the SSNTD, 3D maps of fissile atoms in globular samples, such as mammalian cells, can be calculated while simultaneously obtaining quantitative data. Our approach measures the fission fragment penetration depth needed to calculate the actual track length as opposed to the projected length. Changes in the track length from the standard length allows for the parent fissile isotope location to be determined in the 3D sample to within a ~1.0 µm3 voxel. Another interesting use is to couple FTA with alpha spectroscopy for the isotopic assay of a Pu mixture to distinguish 239Pu from 240Pu. These Pu isotopes are difficult to discern by conventional alpha spectroscopy because of their similar principal alpha energies of 5.156 MeV (239Pu) and 5.168 MeV (240Pu). By measuring the number of spontaneous fissions (principally from 240Pu) and the neutron induced fissions (principally from 239Pu) in a SSNTD, the 239Pu/ 240Pu ratio can be determined using the alpha spectrum of the sample to correct for the presence of other Pu isotopes.

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RMRM 27

Rapid separations of fission products from uranuim-based target materials

Jacquelyn M. Dorhout1,2, [email protected], Kenneth Czerwinski1. (1) UNLV, Los Alamos, New Mexico, United States (2) Los Alamos National Laboratory, Los Alamos, New Mexico, United States

The ability to compare fission products from a radiological event to a known library is imperative for post-detonation nuclear forensics. Current methods for the creation of these fission product libraries include dissolution of an irradiated actinide target, removal of any unreacted actinide, and subsequent separation of any fission products of interest. A new separation method that does not require the complete dissolution of the target will decrease the time, cost, and associated liquid radioactive waste. In this talk, I will discuss two types of uranium-based target materials that have been irradiated and tested with this novel method. Gamma spectroscopy was used to determine extraction yields, and the results will be discussed.

RMRM 28

Developing an accurate algorithm to predict post-detonation urban debris composition

Jerrad Auxier2, [email protected], John D. Auxier1, Howard L. Hall3. (1) Department of Nuclear Engineering , Institute for Nuclear Security , Jefferson City, Tennessee, United States (2) AET-2, Los Alamos National Laboratory, Jefferson City, Tennessee, United States (3) Nuclear Engineering, University of Tennessee, Knoxville, Tennessee, United States

In order to collect and analyze samples in a short period of time, new codes must be developed to predict the composition of the urban debris created during the blast, and they must predict the kinematic effects the weapon has on the urban environment. With ever increasing improvements made in material strengths and building design, more urban infrastructure will survive after a weapon of mass destruction (WMD) detonation; hence altering both surrogate glass composition and large particulate dispersion patterns. To combat these problems, the Nuclear Urban Kinetics Effects Simulator (NUKES) was developed to account for soil composition, building type, infrastructure density, and type of WMD. This will allow the user to calculate the composition of urban debris in the lower continental 48 states within a short period of time; therefore, shortening the analysis time required in the laboratory.

RMRM 29

Analytical characterization of americium using radiometric techniques

Jung Rim1, [email protected], Donivan R. Porterfield1, Dylan J. Klundt1, Lav Tandon2. (1) Actinide Analytical Chemistry, Los Alamos National Laboratory, Los Alamos, New Mexico, United States (2) Los Alamos National Laboratory, Los Alamos, New Mexico, United States

Americium is a man-made transuranic element that can result from nuclear fission reactions, but also results from the beta decay of 241Pu. The analytical characterization of americium to meet

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material specifications for assay and isotopic analysis in pure oxide can be readily performed with a number of radiometric counting techniques. This presentation will discuss the determination of 241Am and 243Am in solid and liquid sample matrixes using gamma spectrometry, alpha spectrometry, and liquid scintillation counting (LSC). The sample mass ranged from nanograms to grams. High-purity Germanium (HPGe) gamma spectrometry was used for both solid and liquid samples with minimal sample preparation. Sample amounts of up to ~3 g were analyzed using gamma spectrometry with the typical sample sizes being in the milligram range. Alpha spectrometry was used to measure isotopic abundances of 241Am and 243Am in prepared americium samples. Alpha spectrometry counting geometries were controlled by either direct-deposition or electrodeposition methods. The gross alpha activity of americium solutions were measured using LSC for assay determinations.

RMRM 30

Making americium hexavalent again

Jenifer Braley, [email protected], Kevin McCann. Chemistry Geochemistry/Nuclear Engineering, Colorado School of Mines, Golden, Colorado, United States

Separation of americium from trivalent lanthanides and trivalent actinides is one of the most difficult elemental separation steps in the periodic table. The ability to complete this separation effectively has ramifications for nuclear stewardship and the nuclear fuel cycle. One separation approach under consideration is to oxidize americium to the hexavalent state, forming a linear dioxo cation. Forcing americium to the hexavalent state provides a path for achieving group actinide (U, Np, Pu, and Am) separation from lanthanides, trivalent actinides, and remaining fission products. If the uranium through plutonium actinides are present, americium could be selectively reduced away from the lighter actinides to provide a clean americium separation from a relatively complex matrix. Thus far only sodium bismuthate, an insoluble oxidizer, has demonstrated the ability to oxidize and maintain Am in the hexavalent state in molar nitric acid for recovery by solvent extraction. The insolubility of sodium bismuthate in aqueous and organic phases could be a limitation in further process development. This work evaluates aqueous soluble Cu3+ periodate (shown on the right) as an oxidant to be used to accomplish a group actinide separation with the extractant diamyl amylphosphonate (DAAP) dissolved in n-dodecane.

RMRM 31

Analytical development of isotope dilution–high performance liquid chromatography–inductively coupled plasma–mass spectrometry (ID-HPLC-ICP-MS) for trace rare-earth quantification in a uranium matrix

Ernest M. Wylie, [email protected], Benjamin T T. Manard, Ning Xu, Lav Tandon. Actinide Analytical Chemistry, Los Alamos National Laboratory, Los Alamos, New Mexico, United States

Determining the trace elemental composition of a uranium material provides a wealth of information for understanding important characteristics including provenance and temporal evolution for a variety of fields including materials design, earth sciences, and forensic studies. Plasma-based mass spectrometry, commonly utilized to this end, tends to suffer from matrix effects and isobaric

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interferences. These hindrances affect both accuracy and precision when attempting to determine trace concentrations in uranium matrices. To address these issues, new techniques have been developed to separate trace components from both one another and the matrix. Here, the analytical development of a combined isotope dilution–high performance liquid chromatography–inductively coupled plasma–mass spectrometry (ID-HPLC-ICP-MS) method will be described and compared with more traditional, external calibration-based analysis. Particular focus on important aspects of forensic analysis including accuracy, precision, analysis time, and required expertise will be provided.

RMRM 32

Bis-(2-ethylhexyl) phosphoric acid impregnated ordered mesoporous carbons for the separation of rare earth elements

Erin R. Bertelsen1, [email protected], Kyle Kluherz1, Gauri Deodhar1, Marisa Adams1, Malcolm R. Davidson2, Brian G. Trewyn1, Jenifer Shafer1. (1) Chemistry, Colorado School of Mines, Golden, Colorado, United States (2) Materials Science, Colorado School of Mines, Golden, Colorado, United States

Adjacent lanthanide separations are among the most challenging elemental separations due to their predominantly fixed trivalent oxidation state and otherwise similar chemical properties. The primary means of accomplishing an adjacent lanthanide separation is to utilize the slight differences in ionic radii between the two lanthanides. The slight differences in ionic radii drive varying retention times on a chromatographic column and can allow chromatographic techniques to complete a separation. Recent advances in materials science have shown ordered mesoporous carbons (OMC materials) to be candidate materials as an inert support for chromatographic separations because of their small mesh size and uniform morphology.1–5 The promising properties of OMC materials should improve the separation efficiency of adjacent lanthanides when paired with classically employed extractants previously used for adjacent lanthanide separations, such as bis-(2-ethylhexyl) phosphoric acid (HDEHP). HDEHP was physisorbed onto two OMC materials. The ability of the OMC materials to recover europium, a model lanthanide, was assessed using distribution and adsorption isotherm studies. These OMC materials provided higher maximum loading capacities and distribution coefficients than its commercially available analog, Ln Resin (Eichrom).

RMRM 33

Implementation of Next Generation Science Standards in high schools: Exploratory study

Anna Pierce, [email protected], Corina E. Brown. Chemistry and Biochemistry, Univ. of Northern CO, Greeley, Colorado, United States

The high demand for a scientifically literate society and workforce led to the creation of the Next Generation Science Standards (NGSS) and their release in April 2013. NGSS is a call to improve science education at the primary and secondary levels and emphasizes the importance of a more concept approach to science. In this presentation, we report on the current state of the research which explores the implementations of the standards (NGSS) at the national level. This research is a phenomenographic study that presents the experience of teachers and experts in the field with

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the implementation of NGSS. Teachers and experts in the field were asked for their opinions regarding the implementation and changes they have made in their lessons and pedagogy in order to accommodate NGSS. From the open-ended interviews several themes were identified regarding the challenges of what to teach and how to teach, class dynamics, and suggestions on how to improve the process.

RMRM 34

Changes in the teaching and assessment of physical chemistry

Richard W. Schwenz, [email protected]. Chemistry, Univ. of Northern Colorado, Loveland, Colorado, United States

Physical chemistry has long provided a challenge for chemistry undergraduate students because it is necessarily requires rapid interchange between the macroscopic and microscopic chemical descriptions, the application of fundamental physics to chemical problems, and the facile use of mathematics to describe and solve problems, and develop theories to describe chemical phenomena, in multiple, very different domains. More recently, the impact of physical chemistry principles to other areas of chemistry and outside chemistry have become more evident in describing the interactions of larger species. The impact of these changes, and those of technology on the teaching as assessment are topics that will be discussed.

RMRM 35

Development of a computational educational laboratory activity to improve students' thinking skills and mental models for understanding intermolecular forces concepts

Kirubel H. Tekletsadik, [email protected]. Chemistry, University of Colorado Denver, Denver, Colorado, United States

This computational laboratory curriculum designs a research project involves the design and development of a computational educational laboratory activity module to improve students' thinking skills and mental models for understanding Intermolecular forces concepts. This presentation describes the educational theory behind the design of the educational activity, a description of the student learning activities in the module, as well as typical results from student interaction with the intermolecular forces computational teaching module in the first trial. The module involves various activities and calculations that students do using the Spartan computational software to improve their qualitative and quantitative understanding of intermolecular forces (e.g., ion-dipole, dipole-dipole, Induced-dipole induced dipole-induced dipole). Results from the preliminary implementation helped with careful re-design of pre and post assessment of learning as well as helped with ideas for improvement in teaching practice to support student interaction during the laboratory activity and to support further improvements in learning outcomes.

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RMRM 36

Development of a conceptual framework for second semester general chemistry

Jerry P. Suits, [email protected]. Chemistry & Biochemistry, University Northern Colorado, Greeley, Colorado, United States

For most of my teaching career-- I thought of the second semester of general chemistry as being based mostly on mathematical operations. Ultimately, I was able to use my research in chemical education to inform my practice—the conceptual framework of this course is based upon two fundamental concepts: chemical potential energy and chemical systems. Every chemist has a deep understanding of chemical potential energy; however, how do students respond? During the first week of class I asked about 200 students to define or describe this term. Only one student responded--he said it was the energy found in chemical bonds (good point) that is released when a chemical bond is broken (a common misconception). Of course, research chemists can always describe their particular chemical system, but can they describe the concept in general terms? A simple but effective answer is that it is shown by a the diagram below. My students have been slow to understand this concept but they are beginning to apply it to hour exams and even to the ACS 2nd term final examination.

RMRM 37

Flow state experiences in chemistry

Kyle Kemats2, [email protected], Jerry P. Suits1. (1) Chemistry & Biochemistry, University Northern Colorado, Greeley, Colorado, United States (2) University of Northern Colorado, Greeley, Colorado, United States

The psychological concept of flow describes the mental state in which the person performing an activity is fully immersed in the activity. This state is characterized by a feeling of balance between challenge and skills, a change in the perception of time, complete concentration on the task, and a

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merging of actions and awareness. Flow has been previously studied in music composition, athletics, and mathematics. However, there has been little work done examining flow in chemical education. Understanding the flow states of chemistry students could help chemical educators possibly employ teaching strategies that might induce these flow states.

RMRM 38

Math-Up Skills Test (MUST) as a predictor of success in general chemistry

Blain Mamiya1, [email protected], Ashley Chen1, Diana S. Mason2. (1) Chemsitry & Biochemistry, Texas State University, Austin, Texas, United States (2) Chemistry, University of North Texas, Corinth, Texas, United States

General Chemistry is known as a gateway course to many STEM (Science, Technology, Engineering, and Mathematics) careers; it is also known as a high-risk course (courses where 30% or more of the students are unsuccessful). Lack of success in general chemistry limits one’s ability to pursue a career in a STEM field. Unsuccessful is determined to be a grade of a D, F, or W (DFW rate) and the DFW rate nationally has been reported to be as high as 47% in general chemistry. One current hypothesis is that students do not possess the necessary mathematics fluency that students once possessed. Students have become too dependent on calculators to increase productivity, and have inadvertently decreased their “number sense” and their ability to complete simple mental math problems without electronic assistance. This study plans to investigate general chemistry students at Texas State University and within in the state of Texas on their ability to solve mental mathematical problems and their dependence on electronic assistance to solve these mathematical problems. Data will be obtained regarding their prior number-sense knowledge using a validated assessment, without and with the use of a calculator. Establishing a correlation and identifying the educational value of the study with the student’s successful completion of first-semester general chemistry are the first steps to develop a plan to help students enrolled in Texas post-secondary educational institutions improve their mathematics fluency.

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RMRM 39

Correlation between different online homework systems, student success, and knowledge decay

Blain Mamiya1, [email protected], Diana S. Mason2. (1) Chemsitry & Biochemistry, Texas State University, Austin, Texas, United States (2) Chemistry, University of North Texas, Corinth, Texas, United States

Student success in chemistry requires students to learn problem-solving skills they normally do not possess when they enter General Chemistry I courses. Many times students solve problems using their misconceptions without the feedback needed to correct their misconceptions. There are many different online homework systems, all designed to provide instant feedback to students when they have answered questions incorrectly and to provide hints or suggestions to solve the problem correctly. This type of feedback helps student’s correct misconceptions before assessments and thereby increase student success in chemistry courses. BUT, what happens with content retention after several days have passed, like on the final exam. Will online homework be advantageous in preventing knowledge decay? Some systems appear to be better than others in helping students retain valid conceptions. This research investigated the correlation between the different online homework systems, knowledge decay, and the effect on student success.

RMRM 40

Six years of steady general chemistry improvement: Results from the program at the University of Utah

Charles H. Atwood, [email protected], Brock Casselman, Braden Ohlsen. Chemistry Dept, Univ of Utah, Salt Lake City, Utah, United States

Over the last six years passing rates and ACS final exam scores have improved at the University of Utah by 20 to 30%. In this presentation we will decribe the active steps taken to make these improvements. Some of the steps include use of a flipped classroom with a dedicated homework system, simple metacognitive exercises to inform students of their knowledge status prior to an exam, better utilization of discussion/recitation sections, and use of the Dunning-Kruger effect to improve the performance of bottom quartile students. Using these steps we have improved the performance of the bottom student quartile on an ASCS final exam by 33 percentile. Shown below is a measure of how much our students have improved in ability on the third midterm exam for the first semester of general chemistry over the years 2014, 2015, and 2016. Most of our steps are readily amenable and usable by other institutions.

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RMRM 41

Towards understanding the radical-S-adenosylmethionine protein MftC, a key compenent in mycofactocin biosynthesis.

John A. Latham, [email protected]. Chemistry and Biochemistry, University of Denver, Denver, Colorado, United States

Mycofactocin, a putative novel redox cofactor, is a member of the rapidly growing family of ribosomally synthesized and post-translationally modified peptides (RiPP). Although its structure and physiological function have yet to be elucidated, a recent bioinformatic study has suggested that its biosynthesis is encoded by the gene cluster mftABCDE(F). Interestingly, these genes are mainly localized to the Mycobacterium genera, including in the pathogens M. tuberculosis, M. ulcerans, and M. avium. Moreover, the bioinformatic study indicated that the precursor peptide, MftA, contains a conserved C-terminal sequence -IDGXCGVY. Recently, we and others showed that the first step of mycofactocin, the C-terminal modification of MftA, is catalyzed by the radical-S-adenosylmethionine (RS) protein, MftC. MftC belongs to a large subfamily of RS proteins that contain an elongated C-terminal domain annotated as SPASM. In addition to the cononical RS [4Fe-4S] cluster, these RS-SPASM proteins also contain 1-2 auxiliary Fe-S clusters. Here, we provide strong evidence for the chemical mechanism for MftC. Moreover, we provide evidence for the function of the Fe-S clusters in MftC through mutational analysis and electrochemical techniques.

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RMRM 42

Does saturation of the isoprenyl side-chain in simple menaquinone analogs, MK-1 and MK-1 (H2), alter folded conformations and redox potentials?

Jordan T. Koehn3, [email protected], Cheryle Beuning2, Benjamin Peters3, Sara K. Dellinger1, Cameron Van Cleave1, Lining Yang4, Dean Crick1, Debbie C. Crans1. (1) Colorado State University, FORT COLLINS, Colorado, United States (2) Chemistry , Colorado State University, Duluth, Georgia, United States (3) Chemistry, Colorado State University, Fort Collins, Colorado, United States (4) Xi'an Medical University, Xi'an, China

Conformations and conformational bias of molecules is exploited by many biological systems as well as in catalytic reactions used in synthesis. Conformational analysis of alkanes, alkenes, and fatty acids has demonstrated that folded or U-shaped conformations do exist and can be energetically favorable. Menaquinones (MK) are essential for electron transport in Mycobacteria, however little is known regarding their conformation, placement within the membrane, or how the degree of unsaturation in the isoprenyl side-chain influences conformation and redox potential. Generally, lipoquinones such as MK or ubiquinone are depicted simply as a “Q” in life science textbooks or in extended conformations in primary literature. This is mostly due to lack of fundamental understanding of this class of molecules. Herein, we demonstrate that contrary to current dogma that MK-1 and MK-1 (H2) adopt folded conformations in organic solvents where MK-1 (H2), which contains the saturated side-chain, has a tighter folded conformation. This illustrates that the degree of unsaturation in the isoprenyl side-chain is not responsible for a folded bias but does influence the finer conformational details. Both MK-1 and MK-1 (H2) interact favorably with model membrane interfaces and MK-1 adopts a folded conformation within the reverse micelle surfactant interface. MK-1 and MK-1 (H2) redox potentials vary with solvent environment and degree of unsaturation in the isoprenyl side-chain with statistical significance. Therefore, the degree of unsaturation affects the redox potential of these simple MKs, which could be attributed to differing folded conformations in solution which could be dictated by the degree of isoprenyl side-chain unsaturation.

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RMRM 43

Structural and electronic consequences of [Cp*] ligand protonation

James D. Blakemore, [email protected]. Department of Chemistry, University of Kansas, Lawrence, Kansas, United States

Pentamethylcyclopentadienyl (Cp*) is typically considered to be an inert ancillary ligand in organometallic chemistry and catalysis, in part due to the stability imparted by its chelating and aromatic nature. However, we have recently demonstrated that [Cp*Rh] complexes bearing diimine ligands undergo protonation to form [(Cp*H)Rh] complexes that can be isolated in pure form. We are exploring structural and electronic factors that govern the unique properties of these complexes, and we have found that protonation enables access to new oxidation states that are relevant to catalytic applications. Recent results in this area will be discussed, including studies of electrocatalysis with the [Cp*H] complexes.

RMRM 44

Development of new reactions utilizing ynol ethers

Brian W. Michel, [email protected]. Chemistry and Biochemistry, University of Denver, Denver, Colorado, United States

Ynol ethers are intriguing substrates that have been shown to participate in a number of interesting reactions owing to the highly polarized nature of the C-C triple bond and their ability to undergo mild thermal isomerization to ketenes. We have developed new methods utilizing these ynol ethers for regioselective access to oxy substituted heterocycles.

RMRM 45

Unequal spin delocalization in allyl and benzyl radicals: conjugation and hyperconjugation effects probed by chemical computations

Daniel J. Van Hoomissen2, [email protected], Shubham Vyas1. (1) Colorado School of Mines, Golden, Colorado, United States (2) Chemistry, Colorado School of Mines, Golden, Colorado, United States

Pi-conjugated radicals are the subject of numerous chemical investigations due to their favorable formation in a wide variety of chemical environments. For example, these species are implicated in the formation of polycylic aromatic hydrocarbons in combustion processes, in the primordial atmospheres of planetary bodies, and even in the interstellar medium of space. Electronic structure calculations were utilized to understand the origin and magnitude of the energetic stability of two ubiquitous, resonantly stabilized radicals, allyl and benzyl radicals. In our approach, a common precursor molecule was utilized to explore the stability of multiple radical centers stabilized varying degress of pi and sigma conjugation. The allyl radical was found to be appreciably more stable than the benzyl radical using bond dissocation energies obtained via modified isodesmic reactions and calculating relative rotational barriers about methylene carbons. This stability was related to the

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extend of the delocalization of the unpaired electron obtained through natural bond orbital calculations. Benzyl radicals were shown to not effectively delocalize the unpaired electron compared to allyl radicals. When either radical site was substituted with methyl groups or the conjugation was extended through double bonds and aromatic rings, natural bond orbital results were able to mirror the trends obtained by energetic analyses. Finally, it was shown that altering the degree of halogen substitution at the radical site also has impacts on relative energetics and the degree of radical delocalization. This work highlights the failure of relying on resonance structures to understand what contributes to the energetic stability of conjugated radical centers and provides fundamental knowledge about how conjugation and hyperconjugation impact the stabilization of nonbonding electrons in these systems.

RMRM 46

1,2-Fluorine radical rearrangements probed by theoretical means

Daniel J. Van Hoomissen, Shubham Vyas, [email protected]. Chemistry, Colorado School of Mines, Golden, Colorado, United States

Devising effective degradation technologies for perfluoroalkyl substances (PFASs) is an active area of research, where the molecular mechanisms involving both oxidative and reductive pathways are still elusive. One of the ignored pathways in PFASs degradation is fluorine atom migration in perfluoroalkyl radicals, which was assumed to be implausible because of the high C-F bond strength. Using density functional theory calculations, it was demonstrated that 1,2-F atom migrations are thermodynamically favored when the fluorine atom was migrating from less branched carbon center to a more branched carbon center. Activation barriers for these rearrangements were within 19-29 kcal/mol, which are possible to easily overcome at mildly elevated temperatures such as used in persulfate oxidation treatments. It was also found that the activation barriers for the 1,2-F atom migration are lowered as much as by 10 kcal/mol when degradation products such as HF assisted the rearrangements. Spin density analyses showed that fluorine moves as a radical species instead of a fluoride anion. These findings add an important reaction to the existing knowledge of mechanisms for PFAS degradation and highlights the fact that 1,2-F atom shifts may be a small channel for isomerization of the intermediates in PFASs degradation.

RMRM 47

Reversal of hydrolytic reactivity of organic molecules: Schiff-bases in reverse micelles

Kelly Hassell, [email protected]. Chemistry, Colorado State University, Fort Collins , Colorado, United States

My research examines the environmental interactions reverse micelles magnify for organic molecules during a reversal in their hydrolytic activity. Specifically, this project investigates synthesized compounds; 3-trifluoromethylamine salicylaldehyde (3TF-S) and 3-trifluoromethylamine-5-chlorosalicyl aldehylde (3TF-Cl), as Schiff bases in a hydrophobic environment. Understanding how Schiff bases hydrolyze in reverse micelles will assists our knowledge in designing complexes used as medicines and diagnostic tools. Schiff base compounds

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are considered major components in catalysis, specifically Jacobsen’s catalyst. Serving as enzyme intermediates in the carbohydrate metabolism, in the condensation products formed with the pyridoxal phosphate (PLP) cofactor and in the functions of the cornea with rhodopsin. Schiff bases have a significant role in developing future pharmacological therapeutics. Schiff bases are organic molecules formed by a condensation reaction between an amine group and a ketone/aldehyde; this reaction is susceptible to hydrolytic attack. In this study, two water insoluble Schiff base compounds were dissolved in AOT/isooctane reverse micellar system to alleviate solubility issues. The partial phase selectivity observable by the interactions of the two probes: 3TF-S and 3TF-Cl, were indicative of a reverse micelle size-dependence. Ultimately, this research demonstrates that hydrolysis of Schiff bases is dependent upon environment. The mode of action for Schiff base compounds in pharmacological applications are directly affected by changes upon the cellular environment. We have observed these changes as function of the differences in the bulk water and interfacial bound water regions of the reverse micelle, of which alters the size of the available water pool for hydrolysis. In therapeutic drug design, hydrolysis is one of the leading contributors to a compound’s degradation. Understanding the reversal of hydrolytic activity could hold great promise for drug discovery and other applications in the pharmaceutical industry.

RMRM 48

Selective functionalization of pyridines and diazines via heterocyclic phosphonium salts

Andrew McNally, [email protected]. Chemistry, Colorado State University, Fort Collins, Colorado, United States

Pyridines are the second most common nitrogen heterocycle observed in FDA approved drugs and related diazines (pyrimidines, pyrazines and pyridazines) are also widely found. Traditional methods to functionalize these heterocycles such as electrophilic aromatic substitution, direct metalation, or radical processes are limited by a number of factors including functional group compatibility, lack of regiocontrol and restricted application on complex pharmaceuticals. Our alternative approach is to selectively transform pyridines and diazines into phosphonium salts and use the unique reactivity of the phosphonium ion to enable, C–C, C–O, C–N, C–S and C–F bond constructions, as well as installing hydrogen isotopes. The reaction to make phosphonium salts uses common reagents, is trivial to perform and has a broad substrate scope including late-stage application on pharmaceuticals. The regioselectivity of the process can also be controlled enabling switching between heterocyles in polyheteroaromatic molecules. Transforming phosphonium salts into important pyridine and diazine derivatives occurs through distinct mechanistic pathways. Direct reactions with nucleophiles form C–C, C–O, C–S, C–N, and C–Hal bonds. Metal-catalyzed cross-coupling, using nickel and cobalt catalysts, is exploited for arylation and alkylation reactions and base-mediated fragmentation reactions form heteroaryl anions that will be used to install deuterium and tritium isotopes. Recently we have discovered a new strategy for heterocycle-heterocycle coupling that proceeds through a ligand-coupling process at phosphorus. Collectively, this program will provide rapid access to pyridine and diazine derivatives that have multiple applications in the pharmaceutical sciences.

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RMRM 49

Synthesis of 1,3,6-trisubstituted fulvene coordination complexes as versatile building blocks for functional materials

Nicholas Williams1, [email protected], Sonya K. Adas1,2, Gary J. Balaich1. (1) Chemistry & Biochemistry, US Air Force Academy Chemistry Research Center, USAF Academy, Colorado, United States (2) Air Force Research Labs, National Research Council, USAF Academy, Colorado, United States

Pentafulvenes are a novel class of cross-conjugated cyclic trienes that can provide versatile frameworks for coordination complexes, organometallic structures and supramolecular assemblies. The majority of work dedicated to fulvene-metal complexes use 6,6’-disubstituted fulvenes. This presentation will highlight our work towards establishing the coordination chemistry capabilities of 1,3,6-trisubstituted fulvene derivatives with various metal ions, including lanthanide (II) metallocene complexes, in order to build tunable fulvene-incorporated functional materials.

RMRM 50

Growth of gold-silver core-shell nanoparticles

Austin Ethridge, [email protected], Murielle Watzky. Department of Chemistry and Biochemistry, University of Northern Colorado, Greeley, Colorado, United States

Noble metal nanoparticle growth can be detected by monitoring the change in Surface Plasmon Resonance optical properties, and can be used to quantify concentrations of metal ion or reductant species present. Here, variations of the Turkevich method were used in solution to deposit silver onto gold seeds in a two-step process. Several synthetic procedures were tested towards favoring growth and minimizing nucleation. Nanoparticle growth and silver ion consumption were followed by UV-Visible spectroscopy and/or Atomic Absorption spectroscopy. The resulting gold-silver core-shell nanoparticles were characterized by Scanning Electron Microscopy paired with Energy Dispersive Spectroscopy and by Dynamic Light Scattering spectroscopy. The effect of reaction temperature and the choice of addition method on the growth of the silver shell were further studied.

UV-Visible spectra of gold-silver core-shell nanoparticle solutions

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RMRM 51

Investigation of a tripodal nickel catalyst for CO2 reduction and hydrogen production

Tessa H. Myren, [email protected], Alyssia M. Lilio, Taylor A. Stinson, Trevor B. Donadt, Oana R. Luca. Department of Chemistry and Biochemistry, University of Colorado Boulder, Boulder, Colorado, United States

Increasing levels of CO2 are implicated in increasing global temperatures and ocean acidification, among other effects. Our efforts to reduce the impact of this gas are centered around its utilization as a hydrogen storage molecule. Thus our goal is to remove the CO2 from the air and convert it to hydrocarbons at low overpotentials in the presence of a proton source. Herein we present our efforts towards the development of a new electrocatalyst platform based on [Ni(R3TREN)(Cl)][Cl]. The x-ray structure of the molecule shows a C3-symmetric ligand motif with a nickel coordination site vicinal to -NH moieties. The presence of such moieties allows for a potential locus of CO2 sequestration to facilitate the pre-binding of CO2 and lowering of the reduction overpotentials associated with the initial reduction and bending of the molecule. We present our progress in the use of this novel electrocatalytic motif for the production of chemical fuels.

RMRM 52

Improvement of transition metal carbide catalyst by tuning nitrogen content in the carbon shell

Daniel Harris, [email protected]. Chemistry, University of Wyoming, Laramie, Wyoming, United States

Hydrogen fuel cells are a promising option for the future as a lightweight, inexpensive and clean power source. A fuel cell splits a hydrogen atom into an electron and a proton; the electron can then be used for electric power before being recombined with its proton in the presence of oxygen to form water. For both parts of this process to be energy-efficient, the fuel cell requires the use of a catalyst. Currently the most popular catalysts are based on platinum, an extremely rare and expensive metal. Because of this, a great deal of research is being done to find more cost-efficient alternatives. One promising area of research is a class of compounds known as transition metal carbides (TMCs) which have been studied as both catalysts and catalyst supports. TMCs are corrosion resistance and active for several energy related reactions like the hydrogen evolution reaction (HER), oxygen reduction reaction (ORR), and oxygen evolution reaction (OER). We have previously developed a low temperature method for synthesizing TMCs through an amine metal anion composite (AMAC) route. This method provides access to several types of TMCs with control over size, shape, composition, and crystal structure and the TMCs frequently had a carbon shell surrounding the carbide particles which could provide further protection of the catalyst. In addition, previous research has found that the incorporation of other atoms, specifically nitrogen, into the carbon support lattice can greatly enhance the catalytic activity. To better understand this phenomenon, the amine precursor in the AMAC synthesis was varied to change the type and amount of nitrogens that were left in the carbon shells. These materials were then subsequently tested for their catalytic activity to determine which type of dopant had the greatest impact on the catalytic activity and how the AMAC method can be used to systematically alter the catalytic activity of TMCs.

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RMRM 53

Carbon–hydrogen bond activation with Tp*MoO(X)Y (X = O, S; Y = Cl, OPh) as a model for xanthine oxidase

David Clair II1, [email protected], Marcos Ortega-Keshmiri2, [email protected], Matt A. Cranswick1. (1) Department of Chemistry, Colorado State University - Pueblo, Pueblo, Colorado, United States (2) East High School, Pueblo, Colorado, United States

Molybdenum and tungsten enzymes are ubiquitous across biological systems and have been structurally grouped into three families. While most Mo/W-containing enzymes perform oxygen-atom transfer (OAT), xanthine oxidase catalyzes the hydroxylation of xanthine to uric acid. Here we aim to model reactions typical of xanthine oxidase using the well understood coordination compound motif, Tp*MoO(X)Y (Tp* = hydridotris(3,5-dimethylpyrazol)borate; X = O, S; Y = Cl, OPh). Reactions of these compounds with triphenylphosphine for OAT has been previously documented, however their reactivity toward C–H bond activation has not been investigated. The synthesis and characterization of the well-known Tp*MoO(X)Y compounds will be presented, along with the investigation of their initial reactivity toward C–H bond activation.

RMRM 54

Characterization of the hydrolysis of select vanadium(V) catecholate complexes and their interaction with a model membrane system

Stephanie Petry2, [email protected], Jordan T. Koehn2, [email protected], Caleb Glover2, Aviva Levina3, Peter A. Lay3, Debbie C. Crans1. (1) Colorado State University, Fort Collins, Colorado, United States (2) Chemistry, Colorado State University, Fort Collins, Colorado, United States (3) School of Chemistry, The University of Sydney, Sydney, New South Wales, Australia

For more than a century, the anti-diabetic properties of a variety of vanadium-containing complexes have been studied; however, anti-cancer activities have been investigated more recently. Vanadium(V) catecholates are of interest due to a recent discovery that one of these complexes has potent activity against breast and pancreatic cancer cells. In this study, the vanadium(V) precursor complex, VO2(HSHED), and two vanadium catecholates, VO(HSHED)CAT and VO(HSHED)DTB, were synthesized, where HSHED = N-(salicylideneaminato)-N’-(2-hydroxyethyl)ethylenediamine, CAT = pyrocatechol, and DTB = 3,5-di(tert-butyl)catechol. Using 51V and 1H solution NMR spectroscopy, the location of the free ligands, CAT and DTB, the precursor complex VO2(HSHED), and the two vanadium catecholate complexes, VO(HSHED)CAT and VO(HSHED)DTB, were investigated in a reverse micelle (RM) model membrane system. Vanadium(V) complexes generally undergo hydrolysis upon introduction in aqueous solution; therefore, the stability of the above three complexes was measured within an aqueous environment and a RM system. Thus, the resulting degradation hydrolysis products of the vanadium precursor and the vanadium catecholates within aqueous solution and a RM interface were characterized. Our results demonstrated that the free ligands and the three vanadium(V) complexes above all penetrated the RM interface, and that the three vanadium complexes all hydrolyzed once inside the RM to a certain extent into various vanadate oligomers. These results are important for understanding the interaction of VO(HSHED)DTB with the cellular membrane, as this complex has shown promising anti-cancer activity.

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RMRM 55

Borate-carbohydrate interactions in the synthesis of novel carbon materials, biofuels and chemical feedstocks

David M. Schubert1,2, [email protected], Michael B. Jacobs1. (1) Department of Chemistry, Metropolitan State University of Denver, Denver, Colorado, United States (2) AvidChem LLC, Lone Tree, Colorado, United States

This presentation reviews recent literature on the use of borate interactions with carbohydrates to produce useful products, including novel forms of carbon, biofuel-related small molecules and chemical intermediates. These interactions are primarily based on the pH dependent reversible reaction of borate with 1,2- and 1,3-diol functionalities abundantly present in carbohydrates to form kinetically stabilized cyclic diesters. This interaction is essential to the functioning of all plants and possibly all living things. Borate, supplied as boric acid or one of its salts, is well known to catalyze isomerizations of many sugars and can strongly influence dehydration and pyrolysis processes. It also acts as an antioxidant for reducing sugars as well as a protecting group to avoid unwanted side reactions in chemical syntheses. A relatively recent application of this chemistry is in the preparation of novel carbon materials, where borate catalyzes initial formation of 5-hydroxymethylfurfural (5-HMF) from glucose and also blocks acetalization of 5-HMF to promote efficient carbonization under hydrothermal conditions. The chemistry of borate-carbohydrate interactions is still largely unexploited. We are currently exploring further applications of this chemistry to produce useful products from sugars, biomass and carbohydrate-rich waste.

RMRM 56

Synthesis and characterization of 1,3-diphenyl-6-aryl/alkyl fulvene chromium complexes

Madelyn Smith, [email protected], Andrew Peloquin, Bryce O'Connell, Sonya K. Adas, Gary J. Balaich, Scott T. Iacono. Department of Chemistry, United States Air Force Academy, Colorado Springs, Colorado, United States

The coordination chemistry of fulvene ligands remains of active interest due to the unique bonding and structural properties in such compounds. The title work is focused around the coordination chemistry of 1,3,6-trisubstituted fulvenes, which have not been as widely studied as their unsubstituted counterparts. Sterically demanding 1,3-diphenyl-6-aryl/alkyl fulvenes provide a robust, structurally and electronically tunable platform for expanding the capabilities of fulvene coordination modes and applications. This work will outline the synthesis of discrete transition metal complexes with these bulky ligands, including the synthesis and full characterization of 1,3-diphenyl-6-R (R = phenyl, styrl, pyrenyl, cyclohexyl) fulvene chromium complexes. This study will also summarize efforts towards the incorporation of these complexes into fulvene supramolecular frameworks.

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RMRM 57

Efforts toward spin state changes in Fe(II) coordination complexes through post-assembly conformational switches

Brooke Livesay, [email protected], Matthew P. Shores. Chemistry, Colorado State University, Fort Collins, Colorado, United States

First row transition metal complexes that undergo spin state changes can provide access to unique molecular sensors. For example, Fe(II) imparts a stark contrast in properties (e.g. absorption, magnetism) when switching between a high spin (S = 2) or low spin (S = 0) state. This spin state change has been achieved through relatively soft environmental changes such as hydrogen bonding, π-interactions and coordination number. Currently, our efforts are focused on anion interactions and pericyclic reactions (i.e. click chemistry) to induce spin state change. Click reactions were chosen for their high yields, stereospecificity and that they can be performed in water. Specifically, these click reactions can cause changes in the coordination environment and an electronic change in the donor atoms around the Fe(II) center which can lead to a spin state change. We are investigating tripodal Fe(II) complexes with simple alkynes that can undergo soft click reactions. Synthesis as well as structural and magnetic characterization for these Fe(II) compounds will be presented.

RMRM 58

Development of chiral main group metal complexes for atom transfer catalysis

Trevor B. Donadt, [email protected], Taylor A. Stinson, Alyssia M. Lilio, Oana R. Luca. Chemistry and Biochemistry, University of Colorado Boulder, Longmont, Colorado, United States

The present work describes the synthesis and characterization of chiral main-group salen complexes [(S,S)-(+)-N,N′-Bis(3,5-di-tert-butylsalicylidene)-1,2-cyclohexanediamino M(III) chloride] for use in atom-transfer catalysis. Based on their pronounced inert pair effect and Lewis acidity, we hypothesize that the metalloids of Group V, Bi and Sb, allow for s-orbital based MIII/MV redox couples that can facilitate efficient olefin aziridination, cyclopropanation, and epoxidation (ACE) reactions with excellent kinetics. Herein we report our progress towards the development of these complexes and spectroscopic observation of intermediates relevant to the ACE reactivity manifold. These studies set the stage for future work on tunable main-group redox catalysts.

RMRM 59

Probing the kinetics of formation of silver nanoparticles prepared via a modified Turkevich method

Haley Sandoe, [email protected], Steven Diaz, Murielle Watzky. Department of Chemistry and Biochemistry, University of Northern Colorado, Greeley, Colorado, United States

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Silver nanoparticles, known to display wide-spectrum antimicrobial properties, are now among the most abundantly produced nanomaterials. Here, silver nanoparticles were prepared via modifications of the Turkevich method, and kinetic probes of their mechanism of formation were explored. The kinetics of silver nanoparticle formation and/or silver ion consumption were followed by UV-Visible spectroscopy (Surface Plasmon Resonance), Ion Selective potentiometry, and Atomic Absorption spectroscopy methods. The resulting sigmoidal curves were fitted to the F-W model of continuous nucleation and fast autocatalytic surface growth, and average rate constants for nucleation and growth were extracted and compared. The effect of citrate concentration, both the reductant and stabilizer in the Turkevich method, and reactants addition order were further studied.

Kinetic curve for the formation of silver nanoparticles

RMRM 60

Synthesis of novel tripodal CMPO ligands for extraction of lanthanides and actinides in nuclear recycling and remediation

Michael L. Hudson2, [email protected], Brandon Wackerle2, Shannon M. Biros1, Eric J. Werner3. (1) Chemistry, Grand Valley State University, Allendale, Michigan, United States (2) Chemistry, Grand Valley State University, Shelby Township, Michigan, United States (3) The University of Tampa, Tampa, Florida, United States

One caveat of the use of nuclear power involves the unsolved problems with long term storage and stockpiling of spent nuclear fuel (SNF). SNF contains environmentally dangerous metals, such as actinides, that can be difficult to isolate. Current methods of remediation utilize organic ligands that coordinate and extract the desired metals. The goal of this project is to develop new organic ligands for the recovery of lanthanides and actinides from spent nuclear fuel using liquid-liquid extraction techniques. Our research focuses on enhancing the selectivity for one type of lanthanide or actinide metal cation over another based on ionic size. New ligands based on tri-substituted benzene scaffolds and optimization of the well-known TREN scaffold were modeled using Density Functional Theory and synthesized by our group. These compounds have been tested for their ability to recover lanthanide and actinide metals from acidic water. The computational and experimental results of these metal-ligand complexes will be presented.

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RMRM 61

Single particle electrochromics

Russell C. Evans, [email protected], Justin Sambur. Chemistry, Colorado State University, Fort Collins, Colorado, United States

Nanostructured tungsten trioxide (WO3) electrochromic devices potentially offer shorter switching times than compact thin films because their high surface area provides shorter ion intercalation path lengths during device operation. Nanostructured electrochromic devices are generally characterized with ensemble-averaging light absorption and electrochemical methods, where the performance of individual particles is forfeited. Here, we report first-of-their-kind single particle electrochromic behavior of individual WO3 nanorods under working device conditions. Specifically, we will focus on how the optical density and ion-intercalation kinetics depend on the physical properties of individual particles.

RMRM 62

Shape-controlled Ce-doped LaNiO3 perovskite as precursors for dry reforming of methane catalysts

Yunkai Zou1, [email protected], Job Lopez1, Jing Zhou2. (1) Chemistry department, University of Wyoming, Laramie, Wyoming, United States (2) Department of Chemistry, University of Wyoming, Laramie, Wyoming, United States

Dry reforming of methane (DRM) utilizes two abundantly available green-house gases to produce industrially important syngas (CH4 + CO2 → 2CO + 2H2). Syngas can be used to produce synthetic petroleum as fuels or chemicals. The conversion of methane, the primary component of natural gas, to higher value products will become increasingly important for our energy, economy and environment. In our study, rod and sphere-shaped LaNiO3 perovskite materials were synthesized using co-precipitation methods as DRM catalysts. Lanthanum substitution by cerium in La1-

xCexNiO3 (x: 0.1-0.5) was also studied. Scanning electron microscopy and energy dispersive spectroscopy were used to confirm the shapes and compositions of the prepared catalysts. X-ray diffraction data suggest the formation of highly crystalline LaNiO3. The LaNiO3 structure of the sphere samples is maintained with a Ce substitution composition up to 0.4. However, additional NiO and CeO2 phases are also formed. Pure LaNiO3 exhibits the DRM reactivity at 600°C with CH4 and CO2 conversions of 51% and 63% and H2 and CO selectivity of 52% and 59%, respectively. The conversions of both CH4 and CO2 gases are increased by more than 20% with the addition of Ce in the structure. 95% CH4 and CO2 conversions can be achieved at 700°C over Ce-doped LaNiO3. Compared to the sphere samples, La1-xCexNiO3 samples in the rod shape exhibit similar DRM reactivity. The effect of lanthanum substitution by cerium on the stability and coke-resistance of the catalysts was further examined in our study and our results demonstrate that stable and active LaNiO3-based DRM catalysts can be obtained by tuning the shape and compositions. The research is sponsored by Academic affairs Energy Fellowships as well as Carbon Engineering Initiative Funds from University of Wyoming.

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RMRM 63

Application and challenges of physisorption characterization on mudrocks

Nerine Joewondo, [email protected], Manika Prasad. Colorado School of Mines, Golden, Colorado, United States

Nitrogen and CO2 adsorption experiments are routinely carried out for the characterization of nanoporous materials and powders, such as zeolites, MOFs, and catalysis. This work presents the experimental technique applied to mudrocks and shales. Shales are fine-grained nanoporous rocks that act as seals and prevent fluids to escape from conventional oil and gas reservoir formations as well as from host formations for CO2. Carbonate-rich shales are termed as mudrocks. Characterization of shales is crucial to understand the storage and flow mechanisms in the formation that would facilitate oil and gas production from shales. Here, we present the isotherms of Nitrogen (77 K) and CO2 (273 K) sorption on various mudrocks and the quantitative pore size distribution (PSD) interpretation using Density Functional Theory (DFT). Clay minerals are prone to alteration at high temperature and pressure and so, the experimental results are sensitive to the chosen outgassing conditions. Thus, the experimental challenge lies in determining outgassing conditions prior to the main experiment. We further discuss the challenges in applying DFT to mudrocks with complex composition. The complex mineralogy with a mixture of clay, organic matter, calcite, and quartz gives rise to irregular and heterogenous pore structure and surface properties. A combination of so-called H3 and H4 hysteresis loops (based on IUPAC definition) with low pressure hysteresis is observed for Nitrogen adsorption in shales. Most commercially available DFT kernels rarely consider low pressure hysteresis. Hence when applied to the isotherms of shales, fitting of the DFT kernels is challenging, particularly in the low pressure regions.

RMRM 64

Condensed phase excitation energies database

Nikita Dubinets1,2, [email protected], Lyudmila V. Slipchenko2. (1) National Research Nuclear University "MEPhI", West Lafayette, Indiana, United States (2) Chemistry, Purdue University, West Lafayette, Indiana, United States

Benchmark studies provide fair comparisons of accuracy and computational cost of different methods; as such, they play a critical role in forming community knowledge base. However, to date, benchmarks for methods capable of describing photochemistry in condensed phase are scare and incomplete. We work on development of condensed-phase photochemistry database by (i) creating and documenting model systems covering wide range of photochemical phenomena in various environments and (ii) providing benchmarks on these systems with various solvation models such as quantum mechanics / molecular mechanics (QM/MM), QM with the effective fragment potential (EFP) embedding, and fragment molecular orbital (FMO) method. The test set will include DNA nucleic bases such as molecule of cytosine in natural environment and in water solution. A preference will be given to systems with available experimental data such as absorption, emission and transient absorption spectra. The following information is documented and stored for general use on external website (cophee.efpdb.org): (i) gas phase geometries; condensed phase snapshots from MD trajectory, (ii)

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gas phase excitation energies at different levels of theory, (iii) QM/MM, QM/EFP, FMO excitation energies for specific geometry snapshots, (iv) plots of excitation energy distributions (i.e., absorption spectra) at different levels of theory, (v) statistical analysis of various sets of data, including average solvatochromic shifts and widths of spectral lines, (vi) information on reference experimental data, (vii) detailed description of all computational protocols, and (viii) sample inputs for gas phase, QM/MM, QM/EFP and FMO calculations.

RMRM 65

Photophysical properties of biological chromophores: Fluorescence quenching of cyanophenylalanine derivatives

Sasha Moonitz, Bryce Berthold, Joshua P. Martin, [email protected]. Department of Chemistry, Metropolitan State University of Denver, Denver, Colorado, United States

We report fluorescence quenching studies of 2-cyanophenylalanine and 3-cyanophenylalanine following excitation to the S1 (1Lb) and S2 (1La) excited states of these biochemically relevant spectroscopic reporters. As site-specific probes, both the ortho and meta derivatives can be used to investigate hydration or paired with a Förster resonance energy transfer conjugate in structural dynamics studies with only slight perturbation of the native peptide geometries. Absorption of an ultraviolet photon by the chromophore results in a π* ← π transition with molar absorptivities similar to common biological probes, such as tyrosine and tryptophan. Due to intermolecular interactions with the nitrile group on the chromophore, the local solvent environment can be monitored by changes in the quantum yield for the S1 ← S0 transition. Both iodide and thiosulfate are shown to be efficient quenching agents of 2- and 3-cyanophenylalanine emission intensity, with Stern-Volmer constants of ~90 M−1. These results are in stark contrast to constants reported for the quenching of 4-cyanophenylalanine by the same anions. Thus, the electronic structures of 2-cyanophenylalanine and 3-cyanophenylalanine are shown to be more sensitive probes of environmental changes in the active regions of biomolecules than other commonly used non-natural amino acids.

RMRM 66

Solid alkane reverse micelles (SARMs) - sodium dynamics in the solid state

Ian Sitarik, [email protected]. Chemistry, Colorado State University, Fort Collins, Colorado, United States

The addition of a relatively small quantity of surfactant to a non-polar alkane allows for disproportionately large amounts of water to be solubilized in the resulting solution. The system is known as a reverse micelle solution and the surfactant has been shown to form nanometer sized layered spheres that encapsulate water with a polar inner shell and a non-polar outer shell. This system in the liquid state with relatively light alkane, such as i-octane (C8H18), has been extensively studied and been shown to exhibit unique physical properties compared to bulk aqueous systems. Measurements intended to reveal details of internal structure and dynamics of these systems can be confounded by the overall micellar motion. Here, a new solid alkane reverse micelle system utilizing a heavy alkane, icosane (C20H42), solid at ambient temperature, is used to quench the

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overall micellar motion and reveal the internal motions. Micellar systems of the type based on a anionic surfactant typically contain sodium ions which counter the oppositely charged sulfonate groups of the surfactant (bis(2-ethylhexyl) sulfosuccinate, AOT). Due to the nanometer sized water volume there is a surprisingly high concentration of sodium ions contained within it which can give rise to unique characteristics. Due to the quadrupolar nature (spin of I>3/2) of sodium nuclei, solid state NMR can be used to illuminate the structure and dynamics in SARMS by magnetization recovery and nutation experiments. Data collected for several model sodium compounds and SARMs with varying water to surfactant ratios will be presented.

RMRM 67

Analysis of the glycemic response and thermal properties of β-glucan substituted starches

Alfred Anderson, [email protected]. Food Science and Nutrition, College of Life Sciences, Kuwait University , Safat, Kuwait

Diabetes Mellitus (DM) is a major public health concern worldwide which can lead to a series of disabling complications and diseases. β-glucans are non-starch polysaccharides that are commonly used as food additives due to their numerous health benefits, including the ability to lower the postprandial glucose response. The aim of this study was to determine the effect of substituting β-glucans on the glycemic response and thermal properties of rice, potato, corn, and tapioca starches. Oat β-glucans were added at 0%, 10%, 20%, and 30% (w/w) to each of the four starch types. β-glucan/starch slurries were lyophilized and incubated with α-amylase solution followed by incubation with amyloglucosidase. Glucose released was measured using the 3,5-dinitrosalicylic acid (DNSA) assay method. Incremental Area Under the Curve (iAUC) was calculated and used to represent the estimated glycemic response of each of the β-glucan/starch composites. Thermal analysis was conducted using a differential scanning calorimeter. An overall reduction in the amount of glucose released after the addition of β-glucans was observed in all of the starch composite types (p ≤ 0.05). Results showed that substitution with 20% and 30% β-glucans resulted in a significant reduction in the glucose release rate and thus improved the estimated glucose response of all starches. Substitution with β-glucans caused a marked increase in the enthalpy of gelatinization, ΔHp, of all starches, but was only statistically significant for tapioca starch alone. Substitution with only 10% β-glucans was enough to cause a significant increase in the ΔHp of blank tapioca starch (p ≤ 0.05). The 20% and 30% β-glucan samples also had significantly higher ΔHp than the blank and the 10% β-glucan samples. The data from this study suggest the potential use of β-glucan as a suitable food ingredient in diabetic food products.

RMRM 68

GC-MS Analysis of biodiesel components derived from the Soxhlet extraction of avocado endocarp and trituration of avocado mesocarp.

Arvin J. Cruz1, Alli Depew1,2, [email protected], Marisa Carman1,2, [email protected], Simwoo Bae1,3, Brian Maricle4. (1) Chemistry, Fort Hays State University, Hays, Kansas, United States (2) Kansas Academy of Math and Sciences, Fort Hays

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State University, Hays, Kansas, United States (3) Daejeon High School for the Gifted, Daejeon, Korea (the Republic of) (4) Biology, Fort Hays State University, Hays, Kansas, United States

Finding alternative sources of renewable energy is on the rise globally. Renewable sources of energy are advantageous because they are biodegradable, less toxic and combusts efficiently. More importantly, raw materials for these sources can be replenished. One alternative source of energy is biodiesel. Biodiesel is a fuel which consists of mono-alkyl esters of long-chained fatty acids obtained from vegetable oil or animal fats. They serve as efficient fuels to run diesel engines. Biodiesel is produced via transesterification of oils wherein glycerine is a by-product. Avocado (Persea americana) is a fleshy fruit with high lipid content, mostly monounsaturated fats, which amounts to 70% of its lipid content. These drupes serve as viable sources of biodiesel. In this research, we use the Soxhlet extraction to extract oil from the stony endocarp and trituration/geometric dilution to extract oil from fleshy mesocarp to produce biodiesel. The solvent used in both methods is hexane. More oil is obtained from the endocarp extraction compared to mesocarp trituration. Biodiesel components are analyzed using GC-MS.

RMRM 69

Biodiesel production: A quality analysis

Joseph Didelot, [email protected], Emily Millward, [email protected], Michael B. Jacobs, Shamim Ahsan. Metropolitan State University of Denver , Lakewood, Colorado, United States

Biodiesel has been used as an alternative fuel to support environmental sustainability and reduce the carbon footprint. The synthesis of biodiesel via a base catalyzed trans-esterfication reaction has been researched thoroughly. Herein, the Biodiesel research group at Metropolitan State University of Denver (MSU Denver) has been conducting research on the production of biodiesel from cooking oil to support sustainability on the Auraria Campus. The goal of the project is to utilize waste cooking oils, produced from campus sources for the production of biodiesel. Production of biodiesel using unused and used cooking oil was conducted on a small scale before scaling the reaction up to a 40 gallon biodiesel reactor. The product was analyzed and compared to commercially available biodiesel. Methods for comparison were the 27:3 test, density, viscosity, water content, IR, and GC-MS. From these analyses, it was shown that the biodiesel that was produced is comparable to commercially available biodiesel.

RMRM 70

Determining kinetic data for the APEH and ACY pathway

Carson Cole, [email protected], David Coffman, Tracy Covey, Nicolas Drysdale. Chemistry, Weber State University, Ogden, Utah, United States

Metabolism is critical for proper the growth and function of cells. Cells contain numerous metabolic pathways all with unique functions. Malfunctioning metabolic pathways have been implicated in numerous disease processes. This study aimed to investigate metabolic flux through the APEH/ACY pathway. APEH/ACY functions catabolically to break down small proteins into their

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constituent amino acids. These amino acids can then be recycled into protein products necessary for the proper growth and function of the cell. The biochemical mechanism of this process has been established; however much less is known about the overall kinetics through the two enzymes. We selected an acetylated dipeptide that produces distinct amino acids based on the activity of each enzyme. Using gas chromatography and mass spectroscopy, it is possible to determine the flux through these two enzymes. This process was able to show different rates of flux in HELA and A549 cancer cells, as well as in normal erythrocytes. This method is important as it can be employed to study the APEH/ACY pathway in different contexts and may help us better understand the biological role of the pathway.

RMRM 71

Measurement uncertainty budgets for certified spectrophotometer calibration filters

Jeff Crawford, [email protected], Melissa Hartwell, Doug Martinez, Jerry Messman. Stranaska Scientific LLC, Fort Collins, Colorado, United States

The certified values for calibration filters used to qualify commercial QC-grade spectrophotometers in FDA-regulated laboratories must be accompanied by uncertainty intervals. We present here our science-based approaches for calculating measurement uncertainty for different filter calibration models.

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RMRM 72

Initialization quality control of a higher-order transfer absorption spectrophotometer

Doug Martinez, [email protected], Melissa Hartwell, Jeff Crawford, [email protected], Jerry Messman. Stranaska Scientific LLC, Fort Collins, Colorado, United States

A higher-order transfer absorption spectrophotometer provides the means to certify optical properties of filters that are intended for use in the qualification of commercial QC-grade spectrophotometers in FDA-regulated laboratories. We present here a novel science-based approach prior to running different certification methods to confirm proper functioning of the calibration spectrophotometer.

RMRM 73

Champion and spectator nanoflakes in mechanically exfoliated MoSe2 thin films identified by single nanoflake photoelectrochemical mapping

Michael A. Todt, Allan Isenberg, [email protected], Justin Sambur. Chemistry, Colorado State University, Fort Collins, Colorado, United States

High resolution photoelectrochemical mapping of mechanically exfoliated MoSe2 nanoflakes (20-400 nm thick) shows inhomogenous photon conversion efficiency at the inter- and intra-flake levels. These single nanoflake measurements show that some nanoflakes have a conversion effiency similar to the bulk, while most nanoflakes are significantly less photoactive, leading to a significant drop in efficiency of nanoflake devices compared to bulk crystal devices. Additionally, a strong correlation between nanoflake area and conversion efficiency has been observed, while 1:1 AFM:photoelectrochemical measurements show no correlation between sheet thickness and conversion efficiency.

RMRM 74

Effect of platinization on sensitivity of commercial Pt microelectrodes

Joseph Staver1, [email protected], Zachary Black3,4, [email protected], Melissa M. Reynolds2,4. (1) Chemical & Biological Engineering, Colorado State University, Fort Collins, Colorado, United States (2) Chemistry Department, Colorado State University, Fort Collins, Colorado, United States (3) Electrical and Computer Engineering, Colorado State University, Fort Collins, Colorado, United States (4) Biomedical Engineering, Colorado State University, Fort Collins, Colorado, United States

Nitric oxide (NO) is a free radical produced naturally by endothelial cells which serves to inhibit platelet adhesion and activation and thereby prevent blood clotting. NO releasing biomaterials have shown promise in preventing platelet adhesion and activation, however accurately measuring physiologically relevant concentrations of NO (3-90 nM) is a non-trivial task. Amperometric

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detection of the 3-electron oxidation of NO to nitrate is the best method available, but commercially available probes often lack the sensitivity to accurately measure NO in such low concentrations. Because platinization of Pt microelectrodes has been shown to increase sensitivity and decrease the detection limits of NO significantly in custom made Pt microelectrodes, the use of platinization may be a promising way to improve the sensitivity of commercially available Pt microelectrodes. In this study, we compare the sensitivity and detection limits of NO before and after platinization of commercial 10 µm and 25 µm OD Pt microelectrodes. All measurements are conducted in an open system with PBS at 25°C. This comparison permits the assessment of the efficacy of the platinization process as a means of improving the sensitivity and lowering the detection limit of commercial Pt microelectrodes to accurately quantify physiologically relevant NO concentrations.

RMRM 75

Measurement evaluation of presumptive out-of-tolerance observations for spectrophotometer calibration filters

Melissa Hartwell, [email protected], Doug Martinez, Jeff Crawford, Jerry Messman. Stranaska Scientific LLC, Fort Collins, Colorado, United States

Calibration filters used to qualify commercial QC-grade spectrophotometers in FDA-regulated laboratories must be recertified periodically in order to verify the suitability of their continued field service use and to upgrade the certified values and uncertainties. We present here science-based procedures to identify presumptive out-of-tolerance (OOT) observations and to confirm the OOT state.

RMRM 76

Characterizing dissolved organic matter in surface waters through excitation-emission fluorescence spectroscopy and parallel factor analysis

Kellen J. Sorauf, [email protected], Sarah Pribil, Rene Flores. Chemistry, Regis University, Denver, Colorado, United States

Polycyclic aromatic hydrocarbons (PAHs) and pesticides are among the most widespread organic contaminants in aquatic environments, however, the inherently complex matrices of natural waters make characterizing these contaminates difficult. The aromatic structures of these contaminants have fluorescence properties in the ultraviolet and blue spectral range. These properties allow for their characterization and validation through excitation-emission matrix (EEM) fluorescence spectroscopy and parallel factor (PARAFAC) analysis. A representative model of surface water contaminates was made using standards of naphthalene, tryptophan, and humic acid and subsequently analyzed through EEM fluorescence spectroscopy and PARAFAC using open source software available in the R environment. Samples from local lakes and rivers in the community were taken and analyzed through the model thereby characterizing the presence of naphthalene, tryptophan, and humic acid contaminants.

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RMRM 77

Fungal pretreatment to improve pyrolysis of lignocellulosic biomass

Kurt Stahlfeld1, [email protected], Erica Belmont1, Karen Wawrousek2. (1) University of Wyoming, Laramie, Wyoming, United States (2) Chemical Engineering, University of Wyoming, Laramie, Wyoming, United States

Lignocellulosic biomass is an abundant renewable feedstock for sustainable production of fuels and chemicals. Thermochemical conversion of the biomass through pyrolysis, in which biomass is thermally decomposed in the absence of oxidizer, is a promising way to convert lignocellulosic biomass into bio-oils, which have potential for use as renewable fuels and chemical precursors. However, pyrolysis currently suffers from the drawbacks of high energy input, low bio-oil production, and low quality bio-oils. These drawbacks are in part due to the recalcitrant nature of lignin present in the biomass. This study examines the impact of a biological pretreatment step prior to pyrolysis of lignocellulosic biomass to improve pyrolysis characteristics, particularly onset temperature of pyrolysis and the hydrocarbon composition of the produced bio-oils. Two species of fungi that are known to degrade lignin, Phanerochaete chrysosporium and Fusarium oxysporum, were utilized for this pretreatment. These fungal strains were incubated with three types of biomass (ground corn stover, ground pine, and ground Miscanthus grass) for varying amounts of time. A Thermogravimetric Analyzer (TGA) was used to pyrolyze the pretreated samples, and the produced oils were collected and analyzed by Gas Chromatography Mass Spectrometry (GCMS). Fungal pretreatment did affect the hydrocarbon composition of the produced bio-oils, as oils from the fungal pretreated biomass produced hydrocarbons not found in pyrolysis of the fungal biomass or the lignocellulosic biomass alone. Additionally, it was observed that different fungal strains produce different hydrocarbon profiles in the bio-oils generated from pyrolysis of a given lignocellulosic feedstock.

RMRM 78

Fatty acid production by an environmental microbe grown in an agricultural co-product stream

Kurt Stahlfeld1, [email protected], Erica Belmont3, Karen Wawrousek2. (1) University of Wyoming, Laramie, Wyoming, United States (2) Chemical Engineering, University of Wyoming, Laramie, Wyoming, United States (3) Mechanical Engineering, University of Wyoming, Laramie, Wyoming, United States

Sustainable biodiesel production is expected to play an increasingly important role in a non-fossil fuel energy portfolio in the future. Current routes to biodiesel largely utilize oils or fatty acids produced from food crops. Photosynthetic bioproduction of fatty acids continues to present a number of challenges, including the high costs of photobioreactors, separation and transesterification. As an alternative biological route to fatty acid production, this study examines the use of non-photosynthetic microbes to accumulate fatty acids for biodiesel production when grown on co-product streams from sugar beet processing that are low in cost and locally available. Several microbes were screened under various conditions for growth rates and fatty acid production. An environmentally isolated microbe was identified that both grew well on the co-product stream and accumulated 33% of the cell dry weight as C16 and C18 lipids, ideal for conversion to biodiesel. Fatty acids were transesterified and the resultant fatty acid methyl esters

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(FAME) were analyzed using gas chromatography (GC). Presented results include the microbe growth curve and the produced FAME composition, as determined by GC, at 24 hour time points over a growth duration of 6 days. Future work, including ongoing optimizations of this system, are discussed.

RMRM 79

Novel pyrylium ion and activated furan/pyrrole mediated cycloadditions

James W. Herndon1, [email protected], Yifan Yin1, Jinhui Hu2, Lalith S. Gamage3, Brennan T. Rose4. (1) Chemistry & Biochemistry, New Mexico State University, Las Cruces, New Mexico, United States (2) New Mexico State University, Las Cruces, New Mexico, United States

Several novel reaction processes have been identified that employ reactive intermediates generated through transition metal mediated cyclization reactions of enyne aldehydes or enyne hydrazone systems. The reaction pathways were initially established through the design of tandem pathways involving stoichiometric coupling with Fischer carbene complexes. These methods as well as recent efforts to accomplish similar transformations using either catalytic transition metal systems or earth abundant metals will be discussed.

RMRM 80

From green process to green bioactive products

Cheng-Wei T. Chang, [email protected]. Utah State Univ, Logan, Utah, United States

Green or natural antimicrobial agents have great potential in the use of healthy and safe food. Recent acquisition of Whole Food by Amazon represents a noticeable example of this trend. Therefore, antimicrobial compounds or disinfecting agents, whether originate from natural or artificial sources, are in high demand in the production of food that can be classified as natural or organic. Despite the market value, the development of such compounds remains challenging since agents from natural sources often have microbial resistance exists while artificial synthetic compounds raise the concern of “Green” and “Organic. To offer a comprised solution, my laboratory has developed an easy synthetic process for generating bioactive carbohydrate ester that shows a broad-spectrum antimicrobial activity against a panel of pathogenic bacteria and fungi. The identified carbohydrate ester consists of naturally occurring carbohydrate and fatty acid. This lead can also been synthesized in large quantity to meet the market demand. A discussion on its identification, evaluation and biological investigation of the lead carbohydrate ester will be presented.

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RMRM 81

Enzymatic ring-opening polymerization (ROP) of lactides: Solvent effects and controlling factors

Hua Zhao1, [email protected], Gabrielle A. Nathaniel2, Princess C. Merenini2. (1) Department of Chemistry and Biochemistry, University of Northern Colorado, Greeley, Colorado, United States (2) Department of Chemistry and Forensic Science, Savannah State University, Savannah, Georgia, United States

Polylactide (PLA), often referred as poly(lactic acid), is a sustainable and biodegradable biopolymer. PLA has a wide range of applications in packaging and horticultural materials, and particularly in biomedical fields such as controlled drug delivery carriers, tissue engineering scaffolds, surgical suture and bone fixation materials. Enzymatic ring-opening polymerization (ROP) is a promising benign method for synthesizing polyesters including PLA. However, there is a lack of understanding of how different solvents affect the degree of polymerization and polydispersity, and what are the controlling factors of this type of reactions. We carried out a systematic study of the ROP reactions catalyzed by different lipases using different solvents including solvent-free, organic solvents and ionic liquids. We found that different solvents and lipases, as well as the water content in enzymes and solvents are crucial to the polymerization process.

RMRM 82

Development of organic photoredox catalysts for organocatalyzed atom transfer radical polymerization

Blaine McCarthy1, [email protected], Garret Miyake2. (1) Chemistry , Colorado State University , Fort Collins, Colorado, United States (2) University of Colorado Boulder, Boulder, Colorado, United States

Organocatalyzed atom transfer radical polymerization (O-ATRP) employs organic photoredox catalysts and alkyl halide initiators to synthesize well-defined polymers of target molecular weights and low dispersity. In this work, a new class of core modified phenoxazine O-ATRP photoredox catalysts will be presented with insight into tuning the absorption profiles, redox properties, and nature of charge transfer for this photoredox catalyst scaffold. These catalyst design parameters will guide the future design of O-ATRP photoredox catalysts to further this polymerization methodology.

RMRM 83

Synthesis and incorporation of thiophene and benzothiophene groups to stabilize RNA structure

Marino J. Resendiz1, [email protected], Haobin Wang2, Lamont Sharp1, Joshua Sturgell1, Douglas Hernandez1. (1) Chemistry, University of Colorado, Denver, Denver, Colorado, United States (2) Chemistry, Unversity of Colorado Denver, Denver, Colorado, United States

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Modifying nucleic acids with small aromatic groups has been used for structural probing, in imaging, or in molecular recognition for biomedical purposes. Thus, it is an attractive strategy that potentially facilitates attaining control of the structure of RNA for therapeutic applications. This work describes the use of thiophene-based probes to obtain strands of RNA with unique biophysical properties via the stabilization of its secondary structure. Density functional theory was used as an aid to explain the observed changes. Thiophene was used as model for duplexes of RNA, while benzothiophene was used to adorn the 5’- and 3’-ends of dodecamers of RNA folding into hairpins. Both aromatic groups were incorporated via standard solid-phase chemistry from their corresponding phosphoramidites. Thiophene was installed at the C2’-O-position of internal sites of RNA [CUACGGAAUCAU] via its 2-methylchloride derivative by treating protected nucleosides in the presence of NaHMDS or NaH. Benzothiophene was incorporated on both ends of strand [GGACUUCGGUCC] via protected glycerol derivatives. All experiments were carried out on biopolymers designed to form one thermodynamically stable structure and analyzed via circular dichroism. Interestingly, modification of both strands within a duplex led to stabilization of the corresponding duplexes, which was explored using density functional theory followed by analysis of structural parameters, i.e., pseudorotational angles, π-π stacking, and covariance matrices. Results indicated that this modification induces a conformational change around the dihedral angle between the glycosidic bond and the C2’-O-methylthiophene. Similarly, the presence of benzothiophene at both ends of the RNA hairpin resulted in stabilization of this structure. Although no modeling has been carried out on this hairpin, it is possible that π-π interactions between both benzothiophene rings are playing a contributing role. In conclusion, thiophene and benzothiophene units can be installed at key positions within various structural elements of RNA to induce its stability. Current research is being carried out to explore the reactivity between these probes to obtain distinct RNA motifs with new biophysical properties.

RMRM 84

Polymer electrolytes for sustainable power storage devices

Cindy C. Browder, [email protected]. Northern Arizona University, Flagstaff, Arizona, United States

The increased demand for lightweight, portable power storage systems has fueled interest in polymer electrolytes. As ionic conductors, polymer electrolytes are readily applied to batteries, capacitors, and related power storage devices. We have developed a solid-phase polymer

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electrolyte with a preparation comprising 100% atom economy and zero waste stream. This presentation will detail the optimization of the formulation of our epoxy-based electrolyte, along with efforts to employ sustainably-sourced feedstocks in its preparation. Electrochemical as well as mechanical attributes will be discussed, as well as the performance of the electrolyte in supercapacitors.

RMRM 85

Design of undergraduate organic laboratory project to introduce heteronuclear NMR of novel synthetic products

Mary Saidov, [email protected], Susan M. Schelble, [email protected]. Campus Box 52, Metropolitan State University of Denver, Denver, Colorado, United States

The typical undergraduate exposure for learning NMR in the organic laboratory secquence stresses proton, as well as some carbon-13, and perhaps some 2D activities. This talk will examine learning opportunities for students in these lab courses for probing heteronuclear NMR and advanced 2D applications. The talk will describe the synthesis of thiophosphoramidates with amino acid moieties, and the subsequent information that can be extracted from 1H, 13C, 31P and 2D NMR. In addition to spectroscopy, other infrequently used analytical probes, such as optical activity, and potential anti-viral applications of the synthons produced will also be discussed.

RMRM 86

Tracing the changing content of organic chemistry

Melvin L. Druelinger2, Allen M. Schoffstall1, [email protected]. (1) Department of Chemistry and Biochemistry, University of Colorado Colorado Springs, Colorado Springs, Colorado, United States (2) Department of Chemistry, Colorado State Univ Pueblo, Pueblo, Colorado, United States

Generations of students have experienced a year-long course sequence in organic chemistry for over a century. We will trace developments in course content from the point of view of available texts and personal observations from the early years to the present. Earlier texts consisted of descriptive approaches to numerous reactions, but at the same time were quite diverse in their approach. Mechanisms first appeared in texts published in the late 1950’s. This presentation will focus on now and then comparisons of the content, presentation and style of text content.

RMRM 87

Incorporating multi-week independent projects into the second semester organic chemistry laboratory: Challenges, successes, and lessons learned

Nicholas C. Kallan, [email protected]. Chemistry, Regis University, Denver, Colorado, United States

The second semester organic chemistry laboratory at Regis University is a 400-level, 2-credit course, which is taken by chemistry and biochemistry majors, as well as students majoring in

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biology and those wanting to continue their studies in other health science fields. This laboratory provides students the opportunity to utilize the techniques learned during the first semester in more complex, multi-step syntheses. In an effort to create a more investigation-based laboratory course, several different multi-week independent projects were generated and implemented, which are conducted during the final four weeks of the semester. The projects are typically carried out in groups of two or four students, depending on the project, and they involve literature searching with SciFinder to find experimental procedures, guided experimental design and execution, as well as a final, formal write-up. Each of the projects will be described, typical student results will be shown, and the challenges, successes, and lessons learned in this endeavor will be discussed.

RMRM 88

“Where do your eyes go?” Using eye movement modeling examples as an instructional tool in organic chemistry – EYE-OC

Melissa Weinrich1, [email protected], Nicole Graulich2, Sascha Bernholt3. (1) University of Massachusetts Boston, Loveland, Colorado, United States (2) Justus-Liebig Universität Gießen, Gießen, Germany (3) IPN Leibniz Institute for Science and Mathematics Education, Kiel, Germany

The introductory organic chemistry course is considered a "gatekeeper" for many professions, particularly for underrepresented minorities. Reaction mechanisms and electron pushing formalism are central to organic chemistry, but students often struggle throughout their educational careers with understanding the meanings underlying these tools. One central reason for students’ difficulties with reaction mechanisms lies in the (missing) link between the representation of a chemical reaction (i.e., symbols, Lewis structures) and the chemical concepts (i.e., knowledge about bond polarity) that must be inferred from the representation. Hence, success in terms of understanding and using reaction mechanisms requires aligning three aspects: 1) understanding the representation, 2) cueing upon the contextually adequate conceptual knowledge, and 3) using this conceptual knowledge to infer an explanation or to make a prediction about the reactivity or the next step of the mechanism. To foster students’ ability in the latter two aspects, scaffolding with an explicit cueing technique might be an appropriate strategy to guide students’ attention while learning organic mechanism. According to Mayer’s cognitive theory of multimedia, learning is facilitated when appropriate connections are made between the explicit picture and the corresponding explanation. We will describe the design and testing of instructional settings with the aim of helping students to make inferences about the chemical concepts implicit in representations of organic reaction mechanisms and to foster metacognition in this process. These settings include so-called eye movement modeling examples. These are visual displays of an expert’s eye gaze, recorded with an eye-tracker, showing the expert’s step-by-step processing of the representation and the expert’s verbal explanation to convey the chemical meaning. Empirical evidence in other fields (e.g., classification of botanical and zoological species; medical diagnosis) indicates that eye movement modeling examples can improve students’ learning in visually complex domains.

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RMRM 89

Investigating how organic chemistry students solve stereochemical problems

Travis Knowles, [email protected], Jerry P. Suits. Chemistry & Biochemistry, University Northern Colorado, Greeley, Colorado, United States

Stereochemistry concepts are often some of the most difficult topics for students to grasp in the organic chemistry curriculum. Several factors may influence students’ abilities to solve stereochemistry problems, including their spatial abilities, strategy choice, and ability to utilize spatial representations. A mixed-method study was conducted to investigate the role that these factors play when novice organic chemistry students solve stereochemistry problems. Eye-tracking data revealed key insights into the cognitive processes that occur while students solve stereochemistry problems. Additionally, qualitive findings provided a better understanding of the different strategies students use for solving these types of problems. The implications of our findings for how stereochemistry topics should be taught will be presented.

RMRM 90

Active learning and students‘ ability to transfer knowledge of organic chemistry to biochemistry

Joshua Chavez2, [email protected], Corina E. Brown1. (1) Chemitry and Biochemitry, Univ. of Northern CO, Greeley, Colorado, United States (2) University of Northern Colorado, Greeley, Colorado, United States

Organic chemistry is often feared by students due to the overwhelming amount of material and difficulty of the subject. With the recent exclusion of organic chemistry from the MCAT, the practicality of the course for premed students has been questioned. Some have suggested the course be replaced with nutrition courses. Others argue that organic chemistry is essential for success in biochemistry. However, the validity of organic chemistry as a prerequisite for biochemistry has also been questioned. Active learning is a popular pedagogical approach for increasing comprehension and promoting higher-order thinking. A branch of active learning, termed gamification, has been popularized within the past decade. In this exploratory study several interventions have been developed, used in classroom, and evaluated through a survey developed by the researchers. The purpose of the survey is to evaluate student’s ability to transfer knowledge of organic chemistry to biochemistry. The results and implications of the exploratory study will be presented.

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RMRM 91

Students’ misconceptions on the major metabolic pathways

Amani Abdugadar1,3, [email protected], Jerry P. Suits2. (1) Chemistry and Biochemistry/chemical education, The University of Northern Colorado, Greeley, Colorado, United States (2) Chemistry & Biochemistry, University Northern Colorado, Greeley, Colorado, United States (3) Chemisty, Benghazi University Almarj Branch, Almarj, Libya

Researchers have previously studied misconceptions on biochemistry topics such as photosynthesis, protein structure, and ATP-production. However, no studies have reported on students’ misconceptions on the major metabolic pathways. Since learning metabolism builds on the students’ prior knowledge, the new materials being learned will be affected by the presence of any misconceptions. Some of these misconceptions will be robust and thus hard to be replaced by the correct concepts. Thus, if students are to learn new material, then these misconceptions must be diminished. The current study focused on the origins of these misconceptions, investigated what misconceptions biochemistry students have, and why students develop misconceptions instead of the proper scientific conception. Our ultimate goal is to help students improve their conceptual understanding of the biochemistry concepts that impact metabolic pathways by developing an animation that targets most of their misconceptions. We gauged students’ prior knowledge (pretest), identified their misconceptions, and designed an instructional intervention to help them develop better, well-constructed conceptual schema (posttest). Evidence found in an initial study suggests that the use of multimedia in helping students understand biochemistry can be used as an effective instructional intervention.

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RMRM 92

Vacancy-ordered double perovskites: Molecule-like structures with band-like behavior

Annalise Nunn, James R. Neilson, [email protected]. Chemistry, Colorado State University, Fort Collins, Colorado, United States

Perovskite semiconductors are a technologically-relevant family of materials, finding applications in field-effect transistors, light-emitting diodes, and low-cost photovoltaics. The compositional and structural diversity of the perovskite family offer a multitude of avenues through which to explore the crystal-chemical relationships that govern the advantageous optical and electronic properties. Vacancy-ordered double perovskites of the general formula A2BX6 are derived from the canonical perovskite structure as a face-centered lattice of isolated BX6 octahedral units bridged by A-site cations in the cuboctahedral voids. We find that Cs2SnI6 is a defect-tolerant semiconductor, with iodine vacancies as the primary donor states, while Cs2TeI6 provides an electronic structure that is defect intolerant. A focus on A2SnI6 compounds, where A = Rb+, Cs+, CH3NH3

+, CH(NH2)2+, and

C7H7+, reveals that the optical gaps remain unchanged and the electronic conductivity is highly

dependent upon choice of cation, even across isostructural and isovalent members of the series. Comparing the electronic behavior across the series as a function of perovskite tolerance factor, t, reveals that compounds with tolerance factors that deviate from t = 1 exhibit reduced carrier concentrations and carrier mobilities, enabling use of the tolerance factor as a proxy for predicting functional properties in these materials. These fundamental studies are critical for improving semiconductor materials for technologically-relevant applications, and provide a platform from which to approach a paradigm of materials by design.

RMRM 93

Sensitization of oxide single crystals with quantum confined semiconductors

Bruce A. Parkinson, [email protected], Lenore Kubie, Kevin Watkins. Chemistry 3838, University of Wyoming, Laramie, Wyoming, United States

We study the fundamentals of electron injection by molecules, quantum dots, quantum confined nanoplatelets and semiconducting nanotubes into large bandgap metal oxide semiconductors. We have been testing a theoretical model proposed by Spitler that predicts that the photocurrent yields and photocurrent-voltage behavior are controlled by the doping density that then determines the field gradient of the Schottky barrier at the electrode/electrolyte interface. The model was shown to be applicable to sensitization by both thiacyanine and ruthenium based sensitizing dyes with the difference of the behavior between the two classes of dyes being attributed to the different distance of the photogenerated hole on the dye from the injected electron that influences the rate of the back reaction. We have extended these studies to monolayers of adsorbed CdSe quantum dots of various sizes on well-characterized TiO2 single crystals with varying doping densities. We are also building on our previous work where we were able to observe sensitized photocurrent quantum yields >1 from multiple exciton generation and collection from PbS quantum dots adsorbed on single crystal anatase electrodes. We have also discovered that silver sulfide (Ag2S) forms nanoplatelets with a height of only 3.5±0.2 Å and are quantum-confined with a 1S exciton Bohr diameter resulting in a confinement ratio of ~12.6. The growth of these NPLs is quantized by layer thickness as indicated by UV-vis spectra

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and steady-state fluorescence spectra. TEM, XRD and AFM analyses of these NPLs support platelet formation along the (202) plane of the β-Ag2S structure. Unlike previous Ag2S studies, the sensitized photocurrent spectroscopy measurements mimic the distinct absorption spectral shapes of the nanoplatlets. We have also shown that photoexcited single wall semiconducting nanotubes can produce sensitized photocurrents on both TiO2 and SnO2 single crystal electrodes. The key to this success appears to be the use of cholate to solubilize the nanotubes that then provides a carboxylate group to bond directly to the oxide surface that increases the electronic coupling.

RMRM 94

Atomic layer etching using thermal reactions: Atomic layer deposition in reverse

Steven M. George, [email protected]. Univ of Colorado, Boulder, Colorado, United States

Atomic layer etching (ALE) is a thin film removal technique based on sequential, self-limiting surface reactions. ALE is the reverse of atomic layer deposition (ALD). This talk will discuss new mechanisms that have been developed by our research group over the last several years for the thermal ALE of metal oxides, metal nitrides and elemental metals. Thermal ALE provides for atomic layer controlled and isotropic etching. Al2O3 ALE will be demonstrated using sequential fluorination and ligand-exchange reactions using HF and Al(CH3)3 as the reactants. TiN ALE will be presented using sequential reactions based on oxidation and fluorination to a volatile fluoride using O3 and HF as the reactants. W ALE will be illustrated using sequential oxidation, conversion to a different metal oxide and fluorination to a volatile fluoride. W ALE employs O3, BCl3 and HF as the reactants. Thermal ALE and ALD together provide the atomic layer processing required for advanced semiconductor manufacturing.

Mechanism for W ALE based on: (A) W oxidation to WO3 using O3; (B) conversion of WO3 to B2O3 using BCl3; and (C) removal of B2O3 as volatile BF3 and H2O using HF.

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RMRM 95

Water nano-droplets containing simple lipid or peptide-additives: Exploring the properties and interactions of solutes with soft materials

Debbie C. Crans1, [email protected], Jordan T. Koehn3, Cheryle Beuning3, Benjamin Peters3, Kaitlin Doucette5, Nicole Knebel6, Cameron van Cleave3, Dean C. Crick4, Michael D. Johnson2. (1) Colorado State University, Fort Collins, Colorado, United States (2) Chem Msc 3c, New Mexico State Univ, Las Cruces, New Mexico, United States (3) Chemistry, Colorado State University, Fort Collins, Colorado, United States (4) Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado, United States (5) Cell and Molecular Biology, Colorado State University, Fort Collins, Colorado, United States

The properties of water nano-droplets have been characterized in detail and can be modified by additives, which subsequently modifies molecular reactivity. Nano-sized water droplets such as reverse micelles have been systematically investigated by the addition of solutes and how the solutes distribute themselves. In the case of hydrophobic molecules, the solutes are anticipated to fully penetrate the interface. One such example is menaquinone-2 (MK-2), a simple hydrophobic lipid (a small isoprenylated naphthoquinone). To investigate how this compound associates within the nano-droplet, MK-2 was first synthesized and then the conformational and chemical properties were characterized. Using 1H NMR spectroscopy, we established for the first time that MK-2 has a folded conformation defined by the isoprenyl side-chain folding back over toward the napthoquinone in a U-shape. The specific details of the U-shape depends on the environmental conditions found in different solvents or nano-droplet. An example of hydrophilic solutes are glycine peptidic derivatives, which also associate with the interface and were found to adopt a folded conformation. However, these peptide derivatives were found to be located in the water pool and associate with the interface from the hydrophilic side as opposed to the hydrophobic MK-2 molecule. The take home messages are that both hydrophilic and hydrophobic molecules can adopt folded conformations, and that hydrophobic and hydrophilic molecules interact and penetrate the interface differently. The interaction of the lipid analogs with membrane interface was also investigated at Langmuir monolayer interfaces with the intent to specify the origin of the effects of the interface and begin to understand the changes on electron transfer rates in simple nanoscale water droplets.

RMRM 96

Doping of biologically produced magnetic nanoparticles

Karen Wawrousek, [email protected], Jacob Rex, Michael Seas, Patrick A. Johnson. Chemical Engineering, University of Wyoming, Laramie, Wyoming, United States

Magnetic nanoparticles naturally produced by magnetotactic bacteria are of particular interest due to their uniform size and properties. These single-domain ferromagnetic nanoparticles are optimized for magnetic strength per particle size. Either magnetite (Fe3O4) or greigite (Fe3S4) magnetic nanoparticles can be synthetized by bacteria, depending on the species of bacteria and environmental conditions. Previous work has shown that these biologically produced magnetic nanoparticles can be doped with metals by a simple addition of the doping metal to the growth media, and this work has focused on doping with single metals commonly found in biological systems. We have doped the magnetic nanoparticles produced by Magnetospirillum magneticum

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AMB-1 with single metals as well as combinations of metals unlikely to be found in a biological system in high concentrations but expected to enhance magnetic properties based on known material properties. We show incorporation of doped metals by X-ray diffraction, use magnetometry to measure changes in magnetic properties, and visualize the doped magnetic nanoparticles by transmission electron microscopy to detect any changes in size or shape. The goal of these studies is customization of these uniform biologically produced magnetic nanoparticles for different applications, ranging from biomedical diagnostics to hyperthermia treatment of cancer.

RMRM 97

Design of visible light organic photoredox catalysts for the synthesis of polymers and small molecules

Chern-Hooi Lim1,2, [email protected], Garret Miyake1. (1) University of Colorado Boulder, Boulder, Colorado, United States (2) Chemistry, Colorado State University , Fort Collins, Colorado, United States

Over the last ten years, visible light photoredox catalysis has developed as a route for small molecule transformations and materials synthesis under mild conditions. Through combined computational and experimental expertise, we have developed strongly reducing dihydrophenazine and phenoxazine organic photoredox catalysts (PCs). These organic PCs exhibit photophysical and electrochemical properties pertinent to photoredox catalysis: strongly reducing excited state, good visible light absorption, redox reversibility, charge transfer excited states and long excited state lifetimes. In particular, we have successfully applied dihydrophenazine and phenoxazine organic PCs for the synthesis of polymers via atom transfer radical polymerization (ATRP) and small molecules via trifluoromethylation and dual Nickel/photoredox catalyzed C-N and C-S cross-couplings.

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RMRM 98

Design, synthesis and application of highly reducing organic photoredox catalysts

Ryan M. Pearson2, [email protected], Garret Miyake1. (1) University of Colorado Boulder, Boulder, Colorado, United States (2) Chemistry and Biochemistry , University of Colorado Boulder, Boulder, Colorado, United States

We report the successful application of N-aryl phenoxazine and N,N-diaryl dihydrophenazine photoredox catalysts for the synthesis of small molecules and polymers. Through pairing computational design and synthetic strategy, catalyst redox properties, absorption profiles, and photophysical characteristics are tailored to achieve desired reactivity. These catalysts, which possess extremely strong excited state reduction potentials, high triplet energies, and long lived lifetimes catalyze a variety of transformations, including carbon-heteroatom cross-couplings, radical substitutions, atom transfer radical additions, and atom transfer radical polymerization.

RMRM 99

Stereoselective synthesis of endoperoxide containing heterocycles

David M. Rubush2, [email protected], Tyler Vavrek1. (1) Benedictine University, Lombard, Illinois, United States (2) Chemistry, Benedictine University, Lisle, Illinois, United States

Endoperoxide containing heterocycles are an important class of molecules in the fight against malaria. We report the stereoselective synthesis of 1,2,4-trioxanes and novel 1,2,4-dioxazinanes

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via phenol dearomatization followed by a peroxy-acetal formation/Michael desymmetrization cascade reaction. Trioxanes and dioxazinanes were formed in high yields as single diastereomers.

RMRM 100

Transition-metal free synthesis of photoredox catalysts for organocatalyzed atom transfer radical polymerization

Matthew D. Ryan2,3, [email protected], Nathaniel Garrison2, Garret Miyake1,3. (1) University of Colorado Boulder, Boulder, Colorado, United States (2) Chemistry & Biochemistry, University of Colorado Boulder, Broomfield, Colorado, United States (3) Chemistry , Colorado State University, Fort Collins, Colorado, United States

Photoinduced organocatalyzed atom transfer radical polymerization (O-ATRP) has emerged as a promising polymerization methodology. A variety of structurally diverse phenazine and phenoxazine photoredox catalysts (PCs) have been shown to operate controlled polymerizations of methacrylates under visible light irradiation, producing polymers with dispersities as low as 1.03. In general, both classes of PCs access highly reducing excited states and form stable radical cations, characteristics that have been found necessary to operate O-ATRP. Although these families of PCs are viable alternatives to their metal counterparts, they are synthesized via palladium-catalyzed reactions, and as such are not completely removed from transition metal dependence. A new synthetic method has been developed to access phenazine structural analogues in a reaction sequence completely free of transition metals. These new PCs maintain high reduction potentials, visible light absorption, and promising reactivity in O-ATRP, offering a more sustainable approach to precision polymer synthesis.

RMRM 101

Synthesis of advanced polymeric architectures using organocatalyzed atom transfer radical polymerization

Bonnie Buss, [email protected]. Chemistry, Colorado State University, Fort Collins, Colorado, United States

The performance of organocatalyzed atom transfer radical polymerization (O-ATRP) centers on the ability of strongly reducing organic photocatalysts (PCs) to mediate an oxidative quenching photoredox catalytic cycle. To demonstrate the utility of this technique for the synthesis of advanced materials, O-ATRP has been adapted to a scalable continuous flow reactor system using a diverse scope of PCs and methacrylate monomers. To further extend the capabilities of this system, the synthesis of complex macromolecular architectures and polymers with targeted functionalities has been explored.

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RMRM 102

Solvent and substituent effects in the electrochemistry of aryldiazonium ions

Surendra N. Mahapatro2, [email protected], James P. McEvoy1, Micah Fernandez2. (1) School of Biological Sciences, Royal Holloway University of London, Egham, Surrey, United Kingdom (2) Chemistry, Regis University, Denver, Colorado, United States

The electrochemical reduction of substituted aryldiazonium tetrafluoroborate salts has been studied in acetonitrile and aqueous acetonitrile phosphate buffer (pH(aq) = 7.0-7.4) by cyclic voltammetry, at platinum and glassy carbon working electrodes. Substituent effects have been analyzed using Hammett substituent constants (σ and σ+). For aryldiazonium salts with electron withdrawing substituents (nitro and cyano), quasi reversible waves were observed in aqueous acetonitrile phosphate buffers. As reported in earlier electrochemical literature, the reproducibility of peak potentials in repeated scans was influenced by electrode fouling and history of the working electrodes with regard to mechanical abrasion. The pH dependence of the diffusion-controlled, quasi reversible waves point to a two-electron/H+process. In addition, our results implicate the anti-diazotate derived from the diazonium ions in aqueous acetonitrile phosphate buffer. Spectrophotometric titrations confirmed the rapid formation of the anti-diazotates of the aryldiazonium ions with electron withdrawing substituents. The role of anion desolvation in dipolar aprotic solvents in diazohydroxide/diazotate formation will be discussed.

RMRM 103

Lithium doped magnesium oxide catalyst for the OCM reaction

Dakota Isaak, [email protected]. Chemistry, Colorado School of Mines, Golden, Colorado, United States

The OCM reaction or oxidative coupling of methane reaction is a reaction in which two methyl radicals are formed and are then joined together to make ethylene. Ethylene, due to its high demand, is made in great amounts around the world. It is a versatile petrochemical that is used mostly in the production of polymers. The current method of making ethylene is thermal cracking of hydrocarbons found in crude oil, breaking down larger petrochemicals into ethylene. This process requires massive amounts of heat and pressure and is very energy intensive. The OCM reaction, with the aid of a catalyst, can occur at relatively low pressures, and its source of fuel is methane, the primary component of natural gas. Lithium magnesium oxide has been found to perform the OCM reaction particularly well and is a commonly studied catalyst for this reaction. Our researched focused on the effect of different crystal structures of the magnesium oxide used to make the catalyst. Knowing that a (111) facet on a material leads to a more active catalyst due to the exposed edges and corners, and the alternating cations and anions. It was hypothesized that by using MgO (111) to make the Li-doped magnesium oxide would increase its catalytic ability. To get a glimpse at the effect the amount of Li in the catalyst, the catalyst was made with different percentages of lithium. A broad range of 1, 3, 5, 7, & 10 percent lithium was used. These materials were characterized by physisorption, TEM, and XRD to help determine what the final structure of these materials was. The overall purpose of this research is to help lower the environmental impact of making ethylene. Methane, a by product of a lot of industrial processes, and a greenhouse gas doesn’t have to be wasted and released into the environment or burned into carbon dioxide and water. It can be used to fuel this OCM reaction and make ethylene, a product that is in high

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demand. This catalyst would not only reduce greenhouse gas emissions but it would be able to produce ethylene in a less energy intensive environment.

RMRM 104

Synthesis of candidate Natural Killer T cell ligands utilizing novel tandem Staudinger and aziridine formation reaction

Teron Haynie, [email protected], Shenglou Deng, Paul Savage. Brigham Young University, Provo, Utah, United States

Glycolipids interact with Natural Killer T cells (NKT cells) via the CD1D receptor, which triggers the role NKT cells play as the bridge between the adaptive and the innate immunities. Glycolipids have been thought to exist endogenously only in beta configurations in mammals, yet recent studies indicate that alpha glycolipids exist in mammals and interact with NKT cells indicating the presence of an unknown glycolipid genesis mechanism. To circumvent this controversial issue, we synthesize twelve novel NKT cell ligand candidates utilizing a novel tandem Staudinger and aziridine formation reaction. This reaction cyclizes a hydroxyl with an amine in a diastereoselective manner creating a new variant of glycosphingolipid. Based on our experience we propose that the endogenous ligand could be one of these heterocycle variants as we have observed cyclization of glycolipids under acidic conditions and it is probable that the biosynthetic pathway passes through the acidic lysosome. These novel structures will help achieve two goals: 1) Identify the structure of the endogenous ligand and confirm which anomer of the glycolipid is responsible for the stimulatory effects 2) Study the stimulatory profiles and structure-activity relationships of these aziridine bearing compounds. This knowledge will aid in understanding how NKT cells have differentiated from naïve T cells.

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RMRM 105

Synthesis of Staphylococcus aureus serotype 5 and serotype 8 linkers for self-adjuvanting vaccine

Sara M. Mata1, [email protected], Paul Savage1. (1) Chemistry and Biochemistry, Brigham Young University, Provo, Utah, United States (1) Brigham Young University, Provo, Utah, United States

Staphylococcus aureus has two predominant capsular polysaccharides: type 5 and type 8. We believe that we can make a self-adjuvanting vaccine by synthesizing Staphylococcus aureus serotype 5 and 8 a later link them to a Q-β particle. The Q-β particle mimics the real bacteria expressing in the outer shell the synthetic serotype 5 or 8 and a T cell activator. It has been shown that this type of vaccine stimulates the host to generate antibodies with high affinity and no cross-reactivity among other similar sugar receptors.

RMRM 106

Transparent wood-based composites

Kyle Foster, [email protected]. Materials Science and Engineering, University of Colorado Boulder, Boulder, Colorado, United States

Transparent wood-based composites are a class of materials to be used as structural components and alternatives to traditional silica glass for infrastructure applications. The primary structural constituent of wood, cellulose, can be rendered transparent through infiltration of the cellular architecture with a refractive index-matching medium. The refractive index of cellulose is around 1.5 (depending on the precise morphology), along with many other commodity polymers. By saturating all cellulose interfaces with a polymer, light can cohesively transmit through the composite. Interfacial compatibility between the two phases is instrumental in maximizing the short and long range visible light transmission by reducing the potential of contaminants, such as air and water from becoming trapped within the composite. Starting with native wood, the cellulose can be isolated via oxidative bleaching of the lignin and chemically modified to match the surface energy or reactivity of the infiltrating phase. It is hypothesized that the degree of interfacial binding between the cellulose and polymer infiltrating phase will directly influence the mechanical and optical properties of the wood-polymer composite. Sufficient mechanical and optical properties, along with

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the thermally insulating ability of polymeric materials, would enable application of transparent wood composites as alternatives to traditional silica glass glazings (e.g. windows, skylights, door panels).

RMRM 107

Synthesis of pyridazinedione derivatives of triazole diesters

Kevin A. Stewart, Allen M. Schoffstall, [email protected]. Department of Chemistry and Biochemistry, University of Colorado Colorado Springs, Colorado Springs, Colorado, United States

Synthesis of 1,2-dihydropyridazine-3,6-diones containing a 1H-1,2,3-triazole ring was achieved starting with an organic azide and dimethyl acetylenedicarboxylate (DMAD), followed by reaction of the triazole diester with hydrazine hydrate, affording an aromatic cyclization between hydrazine and the diester substituents of the triazole to give a fused bicyclic structure. The products of the reaction with hydrazine were clean and required little to no purification. Triazoles having an ester group at N-1 of the triazole gave pyridazinediones rather than reaction with the ester at N-1.

RMRM 108

Antagonistic cytotoxicity of the Cu(II) and Ti(IV) complexes of deferasirox illuminates the complexity of physiological metal speciation

Arthur D. Tinoco, [email protected], Sergio A. Loza-Rosas, Alanis Zayas, Adriana Mendez. Chemistry, University of Puerto Rico Rio Piedras, San Juan, Puerto Rico, United States

The Ti(IV) complex of the iron chelator deferasirox, [Ti(deferasirox)2]2-, is a potent cytotoxic agent that operates in part by decreasing the bioavailability of the labile iron pool. In this work the impact of [Ti(deferasirox)2]2- on the essential metals copper and zinc is examined. The treatment of A549 and MRC5 lung cells with [Ti(deferasirox)2]2- at the IC50 concentrations following supplementation with micromolar levels of Cu(II) and Zn(II) as the labile metal dicitrate species showed distinct behavior with the Cu(II) further decreasing the viability of the cells and the Zn(II) having no effect. These studies prompted examination of the cytotoxicity of the Cu(II) complexes of deferasirox ([Cu(deferasirox)]-) and citrate ([Cu(citrate)2]6-). The [Cu(deferasirox)]- complex exhibited more potent cytotoxicity than [Cu(citrate)2]6-; IC50 = 16.5±1.0 µM vs 31.6±5.0 µM against A549 respectively. Surprisingly, the co-treatment of cells with [Cu(deferasirox)]- and [Ti(deferasirox)2]2- revealed antagonistic cytotoxic behavior. These results indicate a distinct mechanism of attack of the [Cu(deferasirox)]- and [Cu(citrate)2]6- complexes likely owed to a difference in Cu intracellular speciation. A metal deferasirox speciation study performed at micromolar concentrations by reacting equimolar Cu(II), Zn(II), Fe(III), and Ti(IV) with two equivalents of ligands in the presence of 100 µM citrate resulted in the unexpected dominance of the [Cu(deferasirox)]- complex, constituting 66% of the metal bound species. The ability of physiological chelators to dramatically alter the intracellular speciation of metal complexes calls attention to the need of solution standards with biochelators of different metal affinity preferences to better predict the solution fate of these complexes and their therapeutic potential.

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RMRM 109

Coordination chemistry strategies to next generation quantum bits and EPR imaging agents

Joseph Zadrozny, [email protected]. Chemistry, Colorado State University, Fort Collins, Colorado, United States

Electronic spins are quantum objects that are extremely sensitive to their local environments. We exploit coordination chemistry strategies to marshal this sensitivity toward two applications: quantum computing and electron paramagnetic resonance (EPR) imaging. Toward the former, design principles for minimizing said sensitivity are vital to avoid the corruption of information stored in electronic spins. Our approach to such design principles is through fundamental studies of the interaction of paramagnetic transition metal complexes with environmental factors. One particular factor of demonstrated significance is nuclear spin-generated magnetic noise. In this presentation, the importance of such noise in governing the observed properties of electronic spins will be presented. Specific results will show that in the absence of local nuclear spin-generated noise, transition metal complexes can rival the famous nitrogen vacancy spin qubits of diamond in viability. Conversely to the requirements for quantum computing, the sensitivity of metal-based spins to proximate magnetic phenomena may open new diagnostic possibilities for noninvasive EPR-based imaging of physiology. In the latter part of this talk, a new class of candidate EPR imaging probes to harness this sensitivity will be proposed, and initial efforts to design and evaluate such agents will be presented.

RMRM 110

Synthesis of α-Fe2O3 hollow spheres: photonic crystal mimics

Aimee M. Morey, [email protected]. Chemistry, United States Air Force Academy, Colorado Springs, Colorado, United States

Photonic crystals are a classification of materials that have seen a renewed research interest. Synthesis of applicable materials is achievable for 1- and 2-dimensional crystals but 3-dimensional materials still presents a challenge. The main hurdle with these 3D materials is to control long rang periodicity. Hollow spheres of α-Fe2O3 have been synthesized in the micron range with controlled diameters and wall thicknesses for applications as photonic crystal mimics.

RMRM 111

Laser based chemical analysis technique for the characterization and mapping of uranium particles

Benjamin T T. Manard1, [email protected], Ernest M. Wylie1, Ning Xu2. (1) Actinide Analytical Chemistry, Los Alamos National Laboratory, Los Alamos, New Mexico, United States (2) Los Alamos National Laboratory, Los Alamos , New Mexico, United States

Laser ablation – inductively coupled plasma – mass spectrometry (LA-ICP-MS) in tandem with laser induced breakdown spectroscopy (LIBS) was employed to chemically map and characterize

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uranium particles. Single uranium particles were located and characterized for their isotopic abundances and quantification. In addition to the analysis, these particles were also mapped and spatial resolved from surrounding particles such as ion and nickel. The data suggest that the tandem LA-ICP-MS LIBS technique can provide rapid and valuable information for nuclear material safeguards and actinide material characterization.

RMRM 112

Single-particle electrochemistry for solar energy conversion and smart windows

Justin B. Sambur, [email protected]. Chemistry, Cornell University, Brooktondale, New York, United States

Nanomaterials have tremendous potential to transform the way we produce and store energy. Heterogeneity is a general feature among these nanomaterials, with their individual differences in size, shape, and surface sites leading to variable, particle-specific functional properties. Measuring the functional properties of individual nanoparticles, preferably with subparticle resolution, is thus desired and vital to the development of nanoscale materials for energy applications. It is challenging to measure the activity of single-nanoparticle catalysts, however. Here we discuss our recent work on imaging nanomaterials in working solar energy conversion and smart window devices.

RMRM 113

Spectroscopic speciation studies on the Actinide Lanthanide SEParation process (ALSEP)

Gabriela Picayo2, [email protected], Mark P. Jensen1. (1) Colorado School of Mines, Golden, Colorado, United States (2) Chemistry, Colorado School of Mines, Golden, Colorado, United States

Separation of the minor actinides is a critical component to the management and storage of used nuclear fuel. Once uranium, plutonium, and neptunium are removed from the used nuclear fuel, the

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minor actinide americium is the most significant contributor to the radiotoxicity of the resultant waste after 300 years. Due to chemical similarities between the actinides and lanthanides, separating americium from the fission product lanthanides is challenging. Liquid-liquid separation processes that exploit the electronic structure differences between the actinides and lanthanides separate these ions by employing hard bases to bind the lanthanides and soft bases to selectively bind the actinides. The Actinide Lanthanide SEParation (ALSEP) process, a liquid-liquid extraction system which combines the extractant ligands 2-ethylhexylphosphonic acid mono-2-ethylhexyl ester (HEH[EHP]) and N,N,N’,N’-tetra(2-ethylhexyl)diglycolamide (T2EHDGA) in one organic phase, has shown great efficiency and promise for selective recovery of trivalent actinides such as americium, although the stripping step of ALSEP suffers from slow kinetics. In this work, we begin the process of understanding the chemical mechanisms of ALSEP by investigating metal-complex speciation. Using visible spectrophotometry on neodymium we examined both the bulk phase equilibrium species with a conventional spectrophotometer and the mixed extraction system in real time with a OLIS Clarity spectrometer. Initial studies of mixed systems reveal that Nd is extracted into the ALSEP solvent from nitric acid solutions as a mixed HEH[EHP]-T2EHDGA complex without detectable intermediate species. Principal component analysis (PCA) on the series of in-situ time-resolved spectra also reveals the presence of three different organic phase Nd complexes in the scrub step as the Nd is transferred from the mixed HEH[EHP]-T2EHDGA complex to the expected Nd-HEH[EHP] complex at an aqueous pH of 3.5. Three unique Nd-containing species are also observed in the spectra of the stripping step when Nd partitions between the ALSEP organic phase and a DTPA containing aqueous phase. The presence of three species in the scrub and stripping steps indicates that metal transfer from the starting species to the final species is a stepwise process with a transient intermediate. Further research is being conducted to obtain a stoichiometric relationship for the ALSEP extraction complex and to identify the transient species.

RMRM 114

Experimental probes of the formation of silver nanoparticles and gold-silver core-shell nanoparticles

Murielle Watzky, [email protected]. Department of Chemistry and Biochemistry, University of Northern Colorado, Greeley, Colorado, United States

Silver nanoparticles are now amongst the most abundantly produced nanomaterials, in large part because of their antimicrobial properties, which have led to their inclusion in a range of household items. Silver nanoparticles also display a strong optical sensitivity through their Surface Plasmon Resonance properties, which have been utilized in the development of biosensing applications. Here we report experimental probes of the kinetics of formation of silver nanoparticles and gold-silver core-shell nanoparticles, prepared via variations of the Turkevich method, that were collected by UV-Visible spectroscopy, Ion Selective potentiometry, and Atomic Absorption spectroscopy. The effect of different experimental conditions and/or methods will be investigated.

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RMRM 115

Reassociation of multisubunit proteins released from mesoporous silica nanoparticles with conserved enzymatic activity

Brian G. Trewyn, [email protected], Gauri Deodhar. Chemistry, Colorado School of Mines, Golden, Colorado, United States

Mesoporous silica nanoparticles (MSN) with enlarged pores were prepared, characterized, and reversibly dissociated subunits of homotetramer proteins were entrapped in the mesopores as shown by multiple biochemical and material characterizations. When loaded in the MSN, we demonstrated protein stability from proteases and, upon release, the subunits reassociated into active proteins shown through sugar binding. We have demonstrated a versatile and facile method to load multisubunit proteins into MSN with potential applications in enhancing the delivery of large therapeutic proteins.

RMRM 116

Solar-to-hydrogen efficiency: Shining light on photoelectrochemical device performance

James L. Young2, [email protected], Henning Doescher2, John Geisz2, John A. Turner3, Todd G. Deutsch1. (1) MS 1613, National Renewable Energy Lab, Golden, Colorado, United States (2) National Renewable Energy Laboratory, Golden, Colorado, United States (3) Chemistry and Nanoscience, National Renewable Energy Laboratory, Broomfield, Colorado, United States

Direct photoelectrochemical (PEC) hydrogen production aims to provide a clean and cost-effective solar fuel. Solar-to-hydrogen (STH) conversion efficiency is central to evaluating and comparing research results, and it largely establishes the prospect for successfully introducing commercial solar water-splitting systems. Present measurement practices do not follow well-defined standards, and common methods potentially impact research results and their implications. We demonstrate underestimated influence factors and experimental strategies for improved accuracy[1]. Our focus is tandem devices that have the prospect for greater STH efficiency[2], but increased complexity that requires more careful consideration of characterization practices. We perform measurements on an advanced version of the classical GaInP/GaAs design[3] while considering (i) calibration and adjustment of the illumination light-source; (ii) confirmation of the consistency of results by incident photon-to-current efficiency (IPCE), and (iii) definition and confinement of the active area of the device. We initially measured 21.8% STH efficiency using a tungsten white-light source, a calibrated GaInP photovoltaic reference cell, and epoxy-encased photocathodes. In contrast, integrating experimental IPCE over the AM 1.5G solar irradiance showed that less than 10% STH conversion appeared conceivable. We then performed a set of on-sun measurements that gave 16.1% STH, before eliminating indirect light coupled to the sample by using a collimating tube and 13.8% STH efficiency thereafter. However, the value still vastly exceeded the current density expected according to the quantum efficiency measured via IPCE. Finally, suspecting that the illuminated area is poorly defined by epoxy, we use a compression cell for an epoxy-free area definition,

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resulting in 9.3% STH efficiency – a number also compatible with our IPCE results. We propose applying the following standards for future PEC performance reporting: (i) traceable disclosure of the illumination-source configuration (lamp, filters, optics, PEC configuration) and/or its measured spectral distribution; (ii) thorough device-area definition (including confinement of the illumination area and avoidance of indirect light paths); (iii) complementary IPCE confirmation of the solar-generation potential; and (iv) proper consideration of faradaic efficiency.

RMRM 117

Case study: Seven years of solar energy data

David W. Hendricks, [email protected]. Civil & Environmental Engineering, Colorado State University, Arvada, Colorado, United States

Introduction. On 12 July 2010, a 10,000 kW PV solar system of 58 panels (modules) was installed on three roof exposures (east, south, and west) of our home in Arvada, with 24, 16, and 18 panels, respectively. In operation, the direct current outputs for each array are converted to alternating current by three SMA™ inverters, via a Sunny Webbox™; the data are stored in digital form. Analyses. The outputs yield several forms of power and energy, such as: (1) a continuous “power” (kW) curve for each daily solar cycle; and (2) integration of the area under a given curve as “energy” (kWh). These basic forms of data are compiled to yield: (1) daily bar graphs (kWh/day) for each month; (2) monthly bar graphs for each year (kWh/month); and (3) annual bar graphs (kWh/year) for all years of operation. Results. Since the date of installation and to 25 July, 2017 the total energy generated has been 88360 kWh with a calculated CO2 offset 61866 kg and a reimbursement billing credit of $9366. Annual energy generated has averaged 12 MWh/yr; our household domestic demand has been about 9.0 MWh/yr. Our 2013 Tesla™ Model S uses about 0.33 kWh/mile (3.3 MWh per 10000 miles/yr). Our electric energy billing has been “zeroed-out”. Conclusions. From the data downloaded, many kinds of analyses are possible. Examples include: assessing the effects of east and west panel exposures; evaluating the potential of regional scale rooftop solar arrays in reducing grid dependence; speculating on the respective roles of an upgraded electrical grid, batteries, and EV vehicles; examining geographical variation, trends in other countries, and efficiencies. The foregoing illustrates the scope of possible policy directions. Comparison of Solar Metrics. Solar constant = 1365 W/m2 = 32.76 kWh/m2/day Solar radiation at earth’s surface ≈ 16.4 kWh/m2/day Solar radiation at 39.8 N ≈ 5.84 kWh/m2/day [NASA calculation; 4.96 December/ 7.05 June] Solar energy flux generated as AC power = 0.432 kWh/m2/day = [(12,000 kW/year)/(76.06 m2)/(365 days/year)] Solar energy flux measured as inverter AC power and integrated as energy = 0.453 kWh/m2/day = (88360 kWh)/[(1.311 m2/panel)*(58 panels)]/(2567 days) West array = 0.462 kWh/m2/day South array = 0.478 kWh/m2/day East array = 0.418 kWh/m2/day

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RMRM 118

Inverted metamorphic multijunction III-V semiconductors for solar hydrogen production

Todd G. Deutsch1, [email protected], James L. Young1, Myles Steiner1, Henning Döscher3,1, John A. Turner2. (1) National Renewable Energy Laboratory, Golden, Colorado, United States (2) Chemistry and Nanoscience, National Renewable Energy Laboratory, Broomfield, Colorado, United States (3) Fraunhofer Institute for Systems and Innovation Research ISI, Karlsruhe, Germany

During this talk, I will present our progress toward a 20% solar-to-hydrogen (STH) efficiency water splitting photocathode based on III-V semiconductors. We incorporated several key solid-state technological advances to achieve unprecedented efficiencies exceeding 16% STH. The first improvement was to increase the device current via a non-lattice-matched 1.2 eV InGaAs grown using the inverted metamorphic multijunction (IMM) technique developed by NREL. The second modification that led to device improvement was to add a thin n-GaInP2 layer to p-GaInP2 to generate a "buried junction", which increased the photocurrent onset or Voc of the device by several hundred mV and enabled 14% STH efficiency. Finally, we increased the top junction photon conversion efficiency by adding an AlInP "window layer", which is commonly used in solid-state PV devices to reduce surface recombination. Through the use of a collimating tube, we measured our devices outdoors under direct solar illumination and verified over 16% STH conversion efficiency. I will also briefly discuss common experimental pitfalls that can influence the accuracy of measured STH efficiencies of mulitjunction absorbers.

RMRM 119

Solar powered pyrolysis in fixed bed reactor

Asif Hasan Rony1, [email protected], Zhao Sun1, Yuan Zheng2, Maohong Fan1. (1) Chemical Engineering, University of Wyoming, Laramie, Wyoming, United States (2) Department of Mechanical Engineering, University of Wyoming, Laramie, Wyoming, United States

In this work, a solar powered pyrolysis experimental setup was designed, constructed and tested for the ability to run thermochemical conversion reaction in batch and continuous process. First, a 5 kW concentrated solar simulator and supporting components were designed, and procured to produce high concentration solar flux for thermochemical research. In addition, a system to measure the radiation profile produced by the solar simulator was designed and developed for a more accurate energy analysis. Furthermore, a series of flux maps was generated by soltrace® to compare the experimental data with its theoretical counterpart. The solar simulator produced peak solar intensity of over 800 suns in a 10 mm diameter area. The simulator was tested by placing a Quartz glass reactor at the focus of the simulator. The data illustrates use of conventional resources in a scientific experiment through comprehensive measurement and methodological testing. The temporal variance for flux is within ±5%, spatial variance is within ±5% when compared with a soltrace® model. The solar simulator developed for this project has the ability to deliver constant, reliable solar flux which is comparable to actual solar radiation. Pinewood and corn stover were pyrolyzed in a fixed bed reactor, in presence of Fe2O3 catalyst, under concentrated solar light produced by the solar simulator. The Fe2O3 catalyst was characterized with the methods of X-ray diffraction (XRD), nitrogen adsorption and desorption isotherms test, and scanning electron microscopy (SEM).The optimum temperature for maximum

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bio-oil production from pinewood was found to be 500 °C when measured at the front of the reactor. The bio-oil was analyzed using GC-ms and gaseous product was analyzed using micro-GC.

RMRM 120

Increasing efficiency of ethanol production from crude glycerol and Enterobacter aerogenes

Amanda M. Mayes2, [email protected], David L. Dillon1. (1) Chemistry, Colorado State University - Pueblo, Pueblo, Colorado, United States (2) Chemistry, Colorado State University-Pueblo, Pueblo West, Colorado, United States

With global energy consumption consistently on the rise, there is a need to keep up with supply and demand. Current energy sources rely heavily on fossil fuels; however, their emissions cause direct harm to our health and environment. National and global policies have been implemented as an effort to reduce fossil fuel emissions and promote alternative energy sources. One of the more well-known alternative energy sources is biodiesel. During biodiesel production, crude glycerol is a costly waste product that is produced. The costs associated with crude glycerol disposal contribute to an increase cost to the consumer and hinder its ability to compete with fossil fuels on the market. To decrease crude glycerol disposal costs, current research has focused on converting crude glycerol into value added products. Enterobacter aerogenes has been shown to ferment crude glycerol into valuable products such as ethanol. This ethanol can then be used as an alternative energy source, blended into fossil fuels, or put back into the biodiesel production process thus lowering its costs of production. Currently, we are developing a method to analyze and optimize the amount of ethanol produced from crude glycerol and Enterobacter aerogenes.

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RMRM 121

Comparing novel metal-mediated routes to the synthesis of 3,5-disubstituted-2-isoxazolines

Samuel B. Schottler2, [email protected], Ethan Bodak2, Dylan Wardle2, Michael D. Mosher1. (1) Dept Chemistry Biochemistry, University of Northern Colorado, Greeley, Colorado, United States (2) Chemistry and Biochemistry, Unversity of Northern Colorado, Loveland, Colorado, United States

ISO-1 is a known MIF Inhibitor that is a disubstituted isoxazoline. ISO-1 has been shown to exhibit anti-inflammatory properties that would be extremely useful in combating the effects of Type 2 diabtetes and may have cancer treatment possibilities. Recent research has yielded successful results for Pd2+ mediated cyclizations of β, γ-unsaturated oximes to form 3,5-disubstituted-2-isoxazolines in synthetically useful yields. The oximes were synthesized via a Grignard reaction of an aromatic aldehyde with allylmagnesium chloride. Oxidation with PCC formed the corresponding β, γ-unsaturated ketone. Finally, the ketone was refluxed with hydroxylamine hydrochloride to create the oxime. Some exploration has been done on the use of Ni2+ and Hg2+ to mediate the cyclization of the oxime to form isoxazolines. The results are discussed as follows.

ISO-1

RMRM 122

Catalyst-free direct electrochemical cross coupling reactions

Alyssia M. Lilio, [email protected], Charles G. Martin, Trevor B. Donadt, Oana R. Luca. Chemistry and Biochemistry , University of Colorado Boulder, Boulder, Colorado, United States

Pd-catalyzed cross coupling reactions have enabled a myriad of C-C bond-forming synthetic opportunities in organic synthesis. In contrast to recent work based on radical-based cross-coupling chemistries based on Iridium photosensitizers, we now report on our progress in performing direct anodic oxidations of organotrifluorborates (Molander radicals) and carboxylic acids (Kolbe radicals)

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in the absence of a precious metal catalyst. Electrolyses are conducted to make mismatched C-C coupled products, thus providing an unprecedented stoichiometric, scalable means to achieve these types of transformations. Various reaction conditions, applied currents, and electrode materials were tested to optimize the productive coupling.

RMRM 123

Carbon isotope geochemistry of hydrocarbon gases in sandstone reservoirs in the Denver-Julesburg basin, northeastern Colorado

Charles R. Nelson, [email protected]. Blackrock Resources, LLC, Golden, Colorado, United States

Carbon-13 isotope data for methane, ethane, and propane and kinetic isotope fractionation modeling were used to analyze the formation mechanisms of hydrocarbon gases commercially produced from the Terry, Hygiene, and Dakota J sandstone reservoirs in the Wattenberg field area of the Denver-Julesburg Basin, in northeastern Colorado. Hydrocarbon gas formation during thermal maturation of kerogen in sedimentary rocks involves kinetic carbon isotope fractionation that results in a distinctive isotope distribution pattern wherein the ∂13C of methane < ∂13C of ethane < ∂13C propane. The ∂13C values of hydrocarbon gases produced from the Terry, Hygiene and Dakota J sandstone reservoirs ranged from -55.6‰ to -44.6‰ for methane, -33.8‰ to -27.6‰ for ethane, and -30.9‰ to -27.4‰ for propane. For all of the gas samples, the ∂13C values become progressively less negative as the hydrocarbon molecular weight increases. This pattern of isotopically heavier carbon with increasing carbon number is diagnostic of hydrocarbon gases formed by thermogenic cracking of kerogen. Although the range of the ∂13C values for methane fall within the known range of thermogenic methane (∂13C = -56‰ to -47‰), kinetic isotope fractionation modeling calculations indicate that they are roughly 30% to 40% isotopically lighter, when compared to the ∂13C values for ethane and propane, than what might be expected for methane of solely thermogenic origin. The kinetic isotope fractionation modeling calculations indicate that the thermogenic methane ∂13C value ranges from -40.1‰ to -34.4‰ and that the methane in these sandstone reservoirs has a mixed, biogenic (roughly 30% to 40%) and thermogenic (roughly 60% to70%) origin.

RMRM 124

Synthesis of a fluorescently-tagged bile acid to track transepithelial movement in the colon

Hamzah S. Malik, [email protected], Emily Gornick, Yechan Kim, Ugne Dinsmonaite, Mohammed Haq, Jayashree Sarathy, David M. Rubush. Benedictine University, Lisle, Illinois, United States

Bile acid-induced diarrhea affects ~10 million patients suffering from inflammatory bowel diseases and the mechanism behind bile acid-induced fluid loss is still unclear. The primary bile acid chenodeoxycholic acid (CDCA) has been shown to alter tight junctions, increase paracellular permeability, activate Cystic Fibrosis Transmembrane Regulator (CFTR) to increase Cl- secretion, induce oxidative stress, inflammation, and apoptosis in the colon carcinoma cell line, T84. Further, it has been shown that there is a sidedness in CDCA’s action, with CDCA altering tight junction and

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paracellular permeability when present in the apical side and increasing Cl- secretion only when present in the basolateral side of the monolayer. It is unknown how CDCA traverses from the lumen to reach the basolateral side. Thus to identify if CDCA travels trancellularly or paracellularly, we synthesized fluorescently tagged CDCA. Initial functional studies show that the effects of CDCA on cell viability and apoptosis remain unaltered by the addition of the fluorescent tag. Paracellular movement of the fluorescent CDCA is currently being compared to CDCA-induced movement of fluorescently tagged 10 kDa dextran. Structure activity studies of CDCA are also being investigated.

RMRM 125

Photocatalytic degradation of metoprolol: Reaction conditions, intermediates and total reaction mechanism

Elisa Leyva1, Edgar Moctezuma1, [email protected], Kim M. Baines2, Mariana Lopez1. (1) Facultad de Ciencias Quimicas, Universidad Autonoma de San Luis Potosi, San Luis Potosí, San Luis Potosi, Mexico (2) Chem Dept, University of Western Ontario, London, Ontario, Canada

The advanced oxidation of metoprolol (MET) promoted by TiO2/UV system in aqueous media was investigated. Monitoring this process by HPLC and TOC, it was evidenced that while oxidation of MET is quite efficient under these conditions, mineralization of intermediate compounds is not complete. UV-Vis studies of reaction mixtures as a function of time indicated that aromatic compounds remain for several hours and eventually are also oxidized. The formation of several intermediate aromatic compounds was also demonstrated upon continuous monitoring of reaction by means of several analytical techniques such as UV-Vis, IR, HPLC and 1H NMR. These aromatic compounds were eventually oxidized into unsaturated low molecular weight carboxylic and amino acids. A total of nineteen aromatic intermediate compounds were identified by GC-MS analysis. Among these, the hydroxylated compounds stand out since they became quite abundant within the first hour of reaction. Based on experimental results, a total mechanism for photocatalytic oxidation of MET is proposed indicating formation and degradation routes for intermediate compounds. Utilizing several analytical techniques, some fundamental aspects in this oxidative process were elucidated such as the modes and sites of oxidation. Studies on degradation mechanisms are fundamental for future applications of photocatalysis in the removal of pharmaceutical compounds from residual waters.

RMRM 126

Electrocatalytic methods for O-atom transfer reactions

Taylor A. Stinson, [email protected], Trevor B. Donadt, Charles G. Martin, Oana R. Luca. Department of Chemistry and Biochemistry, University of Colorado, Boulder, Colorado, United States

Epoxide drugs have been a focus of pharmaceutical development for the past decades. The synthetic methods to prepare these epoxides, however, require the use of peroxides and peracids which may be biologically hazardous, toxic, or explosive making them difficult to employ at the

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scale of a pilot plant. The present work describes electrochemical methods of O-atom transfer from water to cis and trans olefins towards the formation of epoxides. We also report our efforts to employ the same methods to perform C-H bond insertions in the absence of substrate directing groups. Cyclic voltammetry (CV) is used to diagnose electrolysis parameters and optimal reaction conditions. This work sets the stage for the development of novel synthetic methods that use electricity to generate reactive oxo species from abundant and cheap sources such as water without the need for scale-unfriendly stoichiometric chemical oxidants.

RMRM 127

pKa of humulone

James Landon, [email protected], Michael D. Mosher. Dept Chemistry Biochemistry, University of Northern Colorado, Greeley, Colorado, United States

The purpose of this research is to determine the pKa of Humulone, and use that to determine the ideal pH to brew beer. Finding the pKa of Humulone enables one to find what pH nonprotonated Humulone becomes protonated Humulone. The protonated Humulone isomerizes into Isohumulone, the bittering agent of beer. Beer is ideally brewed at the pKa because the rate of isomerization increases as the pH increases and the solution gets more basic. The deprotonated Humulone isomerizes faster if it is deprotonated causing higher hop extraction rates. However raising the pH too high will decrease enzyme activity in the mash making the beer ferment incorrectly.

RMRM 128

Progress toward the total synthesis of citrinalins A and B

Kimberly Klas2, [email protected], Kazutada Ikeuchi3, Robert M. Williams1. (1) Colorado State Univ, Fort Collins, Colorado, United States (2) Chemistry, Colorado State University, Fort Collins, Colorado, United States

Various fungi of the genera Aspergillus, Penicillium and Malbranchea produce prenylated indole alkaloids that possess a bicyclo[2.2.2]diazaoctane ring system and a variety of biological activity such as insecticidal, cytotoxic, anthelmintic, and antibacterial properties. After the discovery of distinct enantiomers of the natural alkaloids Stephacidin A, Notoamide B and their corresponding diastereomers, from Aspergillus protuberus MF297-2, Aspergillus amoenus NRRL 35660 and Aspergillus taichungensis, the structurally diverse metabolites became of particular biosynthetic interest. The bicyclo[2.2.2]diazaoctane core of the divergent natural metabolites may be enzymatically derived via a putative intramolecular hetero-Diels-Alder cycloaddition. Citrinalins A and B are novel prenylated indole alkaloids that were recently isolated from two fungal spices, Penicillium oxalium and Penicillium citrinum. Interestingly, these secondary metabolites lack the characteristic bicyclo[2.2.2]diazaoctane ring and possess a nitro group that is infrequent in nature. The novel compounds are expected to arise in nature via opening of the azabicyclo skeleton. We are currently investigating a synthetic pathway to mimic the proposed biotransformation in order to further understand the presence of Citrinalins A and B in nature.

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RMRM 129

Synthesis of biologically active 1,2,4-dioxazinanes via aza-Michael desymmetrization

Tyler Vavrek1, [email protected], David M. Rubush2. (1) Benedictine University, Lombard, Illinois, United States (2) Chemistry, Benedictine University, Lisle, Illinois, United States

Endoperoxide containing molecules, such as Artemisinin, are the current frontline treatment for malaria and show potential as anti-cancer theraputics. With high production costs and increasing resistance from malaria parasites, new theraputics are being explored. The use of desymmetrized p-peroxyquinols reacted with aryl imines yield 1,2,4-dioxazinane products as a single diastereomer. Reaction conditions incorporate green chemistry without the use of a catalyst or solvent. The proposed mechanism proceeds via peroxyhemiaminal formation, followed by an aza-Michael desymmetrization reaction. The 1,2,4-dioxazinane products show cytotoxicity towards cancer cell lines.

RMRM 130

Scalable synthesis of antibiotic natural products: Progress toward the total synthesis of baulamycins A and B.

Jonathan R. Thielman2, [email protected], Robert M. Williams1. (1) Colorado State Univ, Fort Collins, Colorado, United States (2) Chemistry, Colorado State University, Fort Collins, Colorado, United States

The baulamycins are a class of structurally-unique, broad-spectrum antibiotic natural products isolated from Streptomyces tempesquensis. Active against Escherichia coli, Bacillus anthracis, and at least one clinically-isolated strain of methicillin-resistant Staphylococcus aureus (MRSA), the baulamycins offer the enticing possibility of probing what may be a novel mechanism of bactericidal activity. To date, study of the baulamycins has been limited by their extreme scarcity. In order to better understand the biological mode of action of the baulamycins, a total synthesis was envisioned which would provide scalable access to both the natural products as well as unnatural derivatives, allowing interrogation of structure-activity relationships within the baulamycin scaffold. A novel synthesis of both left- and right-hand sides (LHS and RHS, respectively) of the baulamycin scaffold has been achieved, giving full control over the configuration at all stereogenic centers, and progress toward the stereoselective coupling of the LHS and RHS is described.

RMRM 131

Synthesis of the Histone Deacetylase inhibitor Largazole and a complex library of analogs for therapeutic utility

Christine Dunne2, [email protected], Le Zhao2, Robert M. Williams1. (1) Colorado State Univ, Fort Collins, Colorado, United States (2) Colorado State University, Fort Collins, Colorado, United States

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Histone deacetylase (HDAC) inhibition has become an increasing focus for cancer therapeutics within the last 10 years. There are currently two FDA approved HDAC inhibitors for use in cancer, SAHA and FK228. Largazole, a natural product derived from the Symploca sp., shows incredible potency towards selective HDAC inhibition that rivals both marketed therapeutics. Within the four Classes of HDAC inhibitors, Class I (HDACS 1, 2, 3, and 8) and II (4, 5, 6, 7, and 9) have shown to be the detrimental targets to the survival of cancer. Largazole’s selectivity towards HDAC isoforms 1 and 2 has made it a promising target for next-generation therapeutic development. To date, >60 analogs of Largazole have been synthesized within the Williams laboratory. This medicinal chemistry approach, creating a library of compounds to test across HDAC isoforms for potency and selectivity, has provided a thorough structure activity relationship analysis of Largazole’s interaction with the HDAC Zn2+ enzyme binding motif, leading to inhibition. These studies have led to the hypothesis that derivatization around the parent core at the thiazole-thiazoline functionality will not affect binding, but in turn increase potency due to enzyme surface electrostatic interactions. Development of novel Largazole bioconjugates both around the Largazole core and via a cleavable bioactive linker have been developed to test across HDAC isoforms and additional biological studies. Bioconjugates, including folic acid derivatives, are hypothesized to have a higher specificity towards cancer cells due to the overexpression of folic acid receptors on their surface. These novel Largazole derivatives are the focus of this research. The developed analogs show promise with increased potency and selectivity towards HDAC Class I isoform inhibition for use as a cancer therapeutic.

RMRM 132

Synthesis of photoredox catalysts for organocatalyzed atom transfer radical polymerization

Nathaniel Garrison, [email protected]. Chemistry, University of Colorado, Boulder, Colorado, United States

5,10-Dihydrophenazine photocatalysts have emerged as effective agents to operate organocatalyzed atom transfer radical polymerization (O-ATRP). O-ATRP offers an alternative to traditional ATRP, where the residual metals can contaminate the polymer product. While phenazine catalysts address the issue of metal-based approaches to polymer synthesis via ATRP, synthesis of the phenazine catalysts themselves still require palladium catalyzed processes. To further reduce the need for metal based catalysts, we have developed a metal-free synthetic method to produce a new class of phenazines. Not only do these catalysts display promising activity in O-ATRP, they also maintain high excited state reduction potentials and visible light absorption. In place of transition metal catalyzed cross coupling reactions necessary for previous catalyst synthesis, we employ a one-pot, multistep, transition-metal free reaction sequence. The low cost of this approach could potentially allow large-scale production of the catalysts, and increase the adoption of O-ATRP for polymer synthesis.

RMRM 133

Isoxazoline compounds for inhibition of tryptophan biosynthesis

Taran DePaola, [email protected], Joshua M. Ellsworth, Cindy C. Browder. Northern Arizona University, Flagstaff, Arizona, United States

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The ongoing quest for broad-spectrum antibiotics with activity against multidrug resistant bacterial strains has led us to investigate essential amino acid biosynthesis pathways for viable drug targets. In the biosynthesis of tryptophan, indole-3-glycerol phosphate synthase (IGPS) has good structural conservation across species, no known human homologs, and a well-established crystal structure and mechanism of action. As such, IGPS is a good target for rational drug design strategies. In our first generation library of potential IGPS inhibitors, we elucidated an isoxazoline lead that warranted further optimization. In this work, we will discuss the use of halogen bonding to improve the binding affinity of next-generation isoxazolines designed to inhibit IGPS.

RMRM 134

Synthesis of benzothiophene models for testing their photochemical reactivity within RNA

Lamont Sharp, [email protected], Douglas Hernandez, Joshua Sturgell. CU Denver, Englewood, Colorado, United States

Benzothiophene-based structures have been used in various processes including pharmaceutical and photosynthetic applications. Its use may present an opportunity to control the structure of RNA. The following work outlines the synthesis of benzothiophene-based probes as models to establish their reactivity prior to insertion into RNA strands. The future application is to elicit strands of RNA with novel reactivity and photophysical properties. Benzothiophene methyl alcohol was synthesized with a 75% yield by reacting benzothiophene in the presence of n-Butyllithium and formaldehyde. The corresponding alcohol was coupled with solketal-tosylate, a protected glycerol derivative, by reacting with sodium hydride in dimethyl sulfoxide to obtain the corresponding acetonide (ca. 75%). The obtained benzothiophene-solketal derivative was treated with trifluoroacetic acid to yield the desired diol, which will be used as an 18-crown-6 type analog, by treating with sodium or potassium salts, to explore the reactivity between both aromatic rings. A model for a 12-crown-4 type structure was derived from treating benzothiophene alcohol with 1,2-dibromoethane(to be treated in the presence of lithium ions). The products of all experiments were confirmed with analysis of structures via NMR, IR, and Mass Spectrometry. In conclusion, benzothiophene and solketal have been used to synthesize molecules that will be used as models to explore benzothiophene-benzothiophene reactivity. These motifs will then be incorporated into RNA to stabilize its secondary structure. Research is continuing in this area to explore the reactivity between these probes within RNA.

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RMRM 135

Reactivity between cisplatin and 8-oxo-7,8-dihydroguanosine – The missing link between oxidative stress on RNA and chemotherapeutic agents.

Austin Skinner, [email protected], Marino J. Resendiz. Chemistry, University of Colorado, Denver, Denver, Colorado, United States

The mechanism and reactivity between RNA and cis-diamminedichloroplatinum (II) (cisplatin) have been studied in-vivo and in-vitro, however not much has is known of cisplatin’s action with oxidatively damaged RNA. The aim of this work is to characterize the modes of action between this drug and, arguably, the most relevant oxidative lesion, 8-oxo-7,8-dihydroguanosine (8-oxo-G). It has been established that cisplatin binds to the N7 position of guanosine and complexes with another guanosine residue also at the N7 position. The properties of the purine ring at the N7 position on 8-oxo-7,8-dihydroguanosine (8-oxo-G) are substantially different than that of its non-oxidized counterpart. Platinum based cancer drugs have been widely in use since 1979 with approval from the FDA with wide spread clinical use in the treatment of various cancers. Similarly, oxidative damage of RNA is a process that has been linked to the development/progression of neurodegenerative diseases. Thus, the action of cisplatin on oxidized RNA is thought to differ as well. In this study, the mechanism of cisplatin on oxidized guanosine was established and the product of this reaction was characterized. Preliminary experiments on 8-oxo-G revealed that the aromaticity of the nucleoside was destroyed when reacted with cisplatin and thus was unobservable through HPLC. In response, a modified molecule of 8-oxo-G was alkylated with a strong chromophore on the 5’ hydroxyl. Synthetic steps to yield this compound were: Bromination and subsequent oxidation of guanosine at the 8 position to yield 8-oxo-G (5.197g, 17.38 mmol, 82%); Protection of the amine at the 2 position using TMS-Cl and PAC (4.54 g, 10.47mmol, 98%); the formation of an acetonide on the C2’ and C3’ hydroxyl groups with 2,2-DMP (2.008 g, 4.24 mmol,73%), deprotection of the PAC group with K2CO3 in MeOH (0.3610 g, 1.064 mmol, 65%), and finally alkylation of the 5’ hydroxyl using excess NaH, cat. TBAI, and 4-(chloromethyl)biphenyl (0.0585 g, 0.1157 mmol, 24.5%). This chromophore labeled 8-oxo-G molecule was used to track the reaction of cisplatin and 8-oxo-G in HPLC. The stoichiometry of the reaction was established, the product was characterized via GC-MS, UV-Vis spectroscopy, X-Ray Crystallography and NMR. The information gathered from these analog experiments was used to test the reactivity of cisplatin on oligonucleotides containing 8-oxo-G lesions and sheds light on the mechanism of cisplatin on oxidized RNA lesions in-vivo.

RMRM 136

Investigations into the conjugate hydrocyanation of α,β-unsaturated aldehydes in organic synthesis

Vu Nguyen, [email protected], Nicholas C. Kallan. Chemistry, Regis University, Denver, Colorado, United States

Cyanide is a useful one-carbon nucleophile that participates in substitution and conjugate addition reactions. Conjugate hydrocyanation reactions of α,β-unsaturated carboxylic acid derivatives and ketones have known since the 1970s. Since then, there have been studies exploring this reaction mechanism on α,β-unsaturated aldehydes. The research explores the synthesis of β-cyanoamides due to cyanide’s unreactivity with α,β-unsaturated amides. Therefore, the synthesis approach

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involves sequential 1,4- and 1,2-additions of cyanide to an α,β-unsaturated aldehyde starting material, followed by oxidation of the intermediate cyanohydrin to an acyl cyanide and displacement with an amine, to provide the target β-cyanoamide. Current efforts have focused on optimizing the first step of the process, which is the double cyanide addition reaction. Different solvents and reaction acids have been explored in various ratios to optimize reaction yield and purity. The reactions were performed in parallel on small scale (~0.2 mmol) and analyzed through GC-MS.

RMRM 137

Educational undergraduate synthesis of N-Methyl Prozac®, a precursor to the classic SSRI fluoxetine

Ryan Dohoney1, [email protected], Stephanie Jensen2, Emily Millward1, Maxwell Dalton3. (1) Chemistry, Metorpolitan State University of Denver, Longmont , Colorado, United States (2) Metropolitan State University of Denver, Northglenn, Colorado, United States (3) Biology , Metropolitan State University of Denver, Denver , Colorado, United States

Fluoxetine, a class of selective serotonin reuptake inhibitors (SSRI), was introduced to the U.S market in 1988 and soon became the most prescribed drug at its time. Individuals affected with depression, bipolar disorder, and some eating disorders rely on the use of an SSRI to maintain an increased level of serotonin in the brain. Approximatly one in ten Americans regularly use an antidepressant for the treatment of depressive disorders1, making SSRI’s a popular treatment option. Fluoxetine has been proven to be a safer and more effective SSRI than many others on the market2 and is still commonly used today. Several universities currently lack opportunities in the discipline of pharmaceutical synthesis at the undergraduate level. This experiment aims to provide a safe and cost effective synthetic method of N-Methyl-Prozac® (NMP), the precursor molecule to Fluoxetine, in an undergraduate laboratory. The following procedure exposes students interested in pharmaceutical chemistry to experimental design and advanced instrumental analysis, including NMR, GC/Mass Spectrometry, and FTIR. Through this method, undergraduate students are encouraged to explore differing methods of reduction and aromatic substitution (SNAr), to influence the reaction speed and yield in the coupling of 3-Dimethlyaminopropiophenone and 4-Chlorobenzotrifloride to synthesize the target molecule, NMP. All of these factors lead to a more advanced understanding of organic chemistry at the undergraduate level, and better prepare individuals for a career in the pharmaceutical or medical industry.

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RMRM 138

Synthesis and characterization of a simple lipoquinone analog: Ubiquinone-2 adopts a folded conformation in solution and within a reverse micelle AOT-water interface

Jordan T. Koehn2, [email protected], Jacob W. Ives2, Dean C. Crick3, Debbie C. Crans1. (1) Colorado State University, Fort Collins, Colorado, United States (2) Chemistry, Colorado State University, Fort Collins, Colorado, United States (3) Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado, United States

Ubiquinones (UBQ) by the definition of their name are ubiquitous in mammals and most bacteria where they are an essential component of the electron transport chain and participate in aerobic cellular respiration; however, little is known regarding the conformation of the isoprenyl side-chain with respect to the quinone moiety within the cellular membrane. Lipoquinones, such as UBQ, are generally depicted as a “Q” in life science textbooks or in extended conformations in primary literature even though it is known that specific conformations are important for reactivity with proteins. There exists the potential for folded UBQ conformations and the ramifications of these conformations are likely to affect the reactivity and function of the molecule. Herein, we first carried out a six-step synthesis to yield ubiquinone-2 (UBQ-2) and then demonstrated that UBQ-2 adopts a folded conformation in organic solvents using 1H-1H 2D NOESY NMR spectroscopic studies. Similarly, using 1H-1H 2D NOESY NMR spectroscopic studies, UBQ-2 was found to interact favorably with the reverse micelle model membrane interface where UBQ-2 adopts a folded conformation within the water-surfactant interface. The characterization of UBQ-2’s conformation is important as this simple, truncated analog serves as a reference for which the naturally occurring UBQ-10 can be compared to and it is likely that the longer isoprenyl side-chain derivative also adopts a folded conformation within the cellular membrane and thus impacting its reactivity in important cellular redox mechanisms.

RMRM 139

Biennial study on two on-road heavy-duty California fleets' fuel specific emissions

Molly Haugen, [email protected], Gary Bishop. University of Denver, Denver, Colorado, United States

Particulate matter (PM) and nitrogen oxides (NOx = NO + NO2) have been significantly reduced in newer model year heavy-duty vehicle emissions as a result of more stringent regulations that have encouraged the improvement of aftertreatment system technologies. The University of Denver has collected three biennial data sets of on-road gaseous (CO, HC, NO and NOx) and PM (particle mass, black carbon and particle number) emission measurements from heavy-duty vehicles (HDVs) at two different locations in California in the spring of 2013, 2015 and 2017. The HDVs at the Port of Los Angeles, CA (1,150 HDVs measured in 2017) comprise one on-road fleet and the other fleet is measured at a weigh station in Northern California near Cottonwood, CA (780 HDVs measured in 2017). The On-Road Heavy-Duty Measurement Setup measures individual HDV’s fuel specific emissions. Vehicles drive under a tent-like structure that encapsulates vehicle exhaust and 15 seconds of data collection is integrated to give fuel specific information. The HDV fleet at the Port of Los Angeles, in conjunction with the fleet at Cottonwood, allows real-world emission factors to be calculated from trucks with different driving modes, after-treatment systems and ages of aftertreatment-systems. The Port of Los Angeles contributes a fleet that is

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fully equipped with diesel particulate filters (DPFs) as a result of the San Pedro Ports Clean Air Action Plan enforced since 2010 that allows only vehicles model year 2007 or newer on the premises. PM emissions have increase in vehicles that have first generation diesel particulate filters, while DPFs on newer model years remain relatively unchanged. Cottonwood’s fleet contains vehicles with and without after-treatment systems, a result of a gradual turnover rate, and fleet PM has decreased at a slower rate than at the Port of Los Angeles. Retrofit DPF instillations on older model year HDVs are partially responsible for the decrease in PM emissions. The contrast in fleets, studied over multiple years, has given the University of Denver a comprehensive data repository to quantify on-road vehicle emission trends on individual vehicles as well as categories of vehicles. Here, the 2017 campaign results will be discussed and compared to previous campaigns.

RMRM 140

Combining Excel and electronics: A new way for reviving instrumentation, adding capabilities, and making new analytical systems

Scot Abbott, [email protected]. R&D, Phoenix, Pittsburgh, Pennsylvania, United States

The typical problems many researchers face are the cost of making special measurements, and the cost of repair or replacement of broken instrumentation. Few chemists have the skill set to integrate the electronics, software and metrology issues involved for making new measurement systems or repair broken instruments. With broken/legasy instruments, the basic hardware is usually good, but the software has gone obsolete or some expensiveunavailable electronic component(s) failed. Sadly, the cost of repair technicians exceeds the annual budget of research group. These factors are often severe roadblocks to important research. We developed a system integration tool by combining high performance electronics with Excel. We have used this (1) Develop a new analytical system, (2) Evaluate some commercial instruments, (3) Revive a few broken instruments and (4) Add new capabilities to a system. During this project, we took full advantage of the properties of Excel to develop several potent data evaluation tools. Several examples will be provided and the important elements (Dynamic range, I/O types, Resolution, Programmability, Speed) will be discussed.

RMRM 141

Getting the most from Excel in experimentation and instrumentation

Scot Abbott, [email protected]. R&D, Phoenix, Pittsburgh, Pennsylvania, United States

The practice of analytical chemistry, as well as the education of analytical chemists has been stromgly affected by the expensive, specialized commercial instrumentation. On the one hand,these provide very high sensitivity and selectivity for many analytical determinations.Unfortunately, many laboratories cant afford them,or afford to repair them. At the same time, many analytical chemists have becoime trained more as instrument operators, specializing in software menus at the expense of solid unserstandings. Instrument vendors use closed source software, which are used used to maximize profits, but also sometimes hide

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deficiencies of sensors or design. In our laboratories, we have faced similar problems, unable to have all the expensive instruments, and unable to repair some of the ones we have as they failed. We also needed to develop a chromatographic system which requires 4 columns and 6 detectors for an exceptionally difficult assay, and nothing was commercially available. To meet all these needs, we chose to develop a complete system integration tool (DAQ2GO(R) which combined Excel(R) with high performance electronics, and apply it to integrate commercially avaiable components into a complete system. .We designed it to serve our needs and not require programmers or electrical engineers for practical applications.. We have now used this system to revive broken instruments, develop new measurement systems, add lab automation, evaluate data treatment techniques and evaluate some commercial instrumentation. The combination of the easy programmabiltiy of Excel with stable, high performance electronics also provides an excellent learning environment for students of analytical chemistry. Taking data, and making comparisons is done readily and seamlessly in Excel that student time is spent learning about making good measurements, rather than learning the menus on some commercial instrument.

RMRM 142

Does ingestion of the anticoagulant rodenticide Chlorophacinone make American kestrels “appear” older when estimating age based on pentosidine concentrations in skin samples?

Randal S. Stahl1, [email protected], Carol Furcolow1, Katherine Horak1, Barnett A. Rattner2. (1) National Wildlife Research Center, US Department of Agriculture, Fort Collins, Colorado, United States (2) Patuxent Wildlife Research Center, US Geological Survey, Beltsville, Maryland, United States

We are investigating the use of chemical markers to estimate the age of wildlife specimens. Pentosidine concentration in skin samples increases with age apparently due to the formation of stable cross links in the collagen pool. Concentration of the advanced glycation end (AGE) product pentosidine (Ps) was determined in skin samples collected from 2-3 year old American kestrels (Falco sparverius) fed the first generation anticoagulant rodenticide (AR), Chlorophacinone (CPN)

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in a mechanically or biologically incorporated meat bait. Secondary exposure to ARs in raptors due to feeding on rodents that have ingested baits may cause adverse effects (coagulopathy) that can potentially lead to death. We used an HPLC method with florescence detection following acid hydrolysis of the skin sample to determine Ps concentration. Results indicated that Ps concentrations differed significantly by kestrel age class but was not affected by dietary CPN at concentrations (0.15, 0.75 and 1.5 mg/g wet weight) fed over a seven day period. Details of the method and results are presented.

RMRM 143

Analysis of gas-phase mixtures of methane and propane by 1H NMR spectroscopy

Jason Widegren, [email protected], Christopher Suiter, Thomas Bruno. NIST, Boulder, Colorado, United States

The use of nuclear magnetic resonance (NMR) spectroscopy for the analysis of gas-phase mixtures is remarkably rare. This seems to be due in part to a commonly held (but erroneous) notion that NMR spectroscopy does not work on gases. In fact, NMR spectroscopy is just as sensitive to nuclei in the gas phase as it is to nuclei in any other phase. However, compared to the analysis of liquid-phase samples, the analysis of gas-phase mixtures by NMR spectroscopy does present significant challenges. First, sample concentration is inherently low in the gas phase. Second, sample preparation and storage are considerably more complicated for gas-phase samples. Third, spin-lattice relaxation times can be very short in the gas phase, which broadens the spectral peaks and potentially affects quantitation. Fourth, the adsorption of less volatile components on the walls of the sample tube can cause measurement errors. Fifth, pressure-dependent effects such as diffusion may affect the NMR measurement under some conditions. Despite the challenges, NMR spectroscopy offers some important advantages over gas chromatography, including shorter analysis time (largely due to simpler calibration requirements) and potentially better accuracy. In this presentation, we will discuss recent experiments that were designed to help us better understand the challenges associated with gas-phase mixture analysis by NMR spectroscopy. Specifically, gravimetrically prepared mixtures of methane and propane were analyzed by NMR spectroscopy under a variety of conditions, and the analyses were compared to the known mixture compositions.

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RMRM 144

Comparing the cooperativity of membrane insertion between C2AB tandem domains of synaptotagmin-7 and synaptotagmin-1

Hai T. Tran, [email protected], Lauren Anderson, Jefferson D. Knight. Chemistry Dept Campus Box 173364, University of Colorado Denver, Denver, Colorado, United States

Synaptotagmins (Syt) play an important role in exocytosis: their two cytoplasmic C2 domains, C2A and C2B, serve as Ca2+ sensors to trigger fusion of secretory vesicles with the plasma membrane. Two proteins of this family, Syt1 and Syt7, are structurally analogous but localize to different populations of secretory vesicles. While Syt1 is responsible for fast release of neurotransmitters, Syt7 is involved in slower processes such as hormone secretion. It has been previously shown that the two C2 domains of Syt1 exhibit cooperative membrane binding; i.e., the C2A and C2B domains penetrate deeper into membranes as the C2AB tandem than as individual C2 domains. In contrast, our previous study suggested that the two C2 domains of Syt7 bind membranes independently, based on their kinetics of dissociation from liposomes. Here, we studied the interdomain interaction of Syt7 and Syt1 C2 domains by measuring Ca2+ sensitivities, dissociation kinetics, and insertion depth of individual and tandem domains during binding to synthetic liposomes with physiologically relevant lipid compositions. The Syt7 C2AB tandem was found to have greater Ca2+ sensitivity than either single domain from equilibrium Ca2+ titration data. Stopped-flow fluorescence spectroscopic measurements show that Syt1 C2AB dissociates much slower than either of its isolated C2 domains while for Syt7, the largest population of the C2AB tandems dissociate at a rate comparable to the individual C2A domain and a subpopulation dissociates at a much slower rate. Furthermore, like Syt1, when present in the C2AB tandem, the C2B domain of Syt7 penetrate membranes more deeply than it does as individual domain, suggesting cooperative insertion. Based on these findings, we propose that the C2 domains of Syt7 coinsert into membranes as they do in Syt1, but interdomain cooperativity in Syt7 contributes less to the energetics of membrane binding than in Syt1.

RMRM 145

Unravelling the role of tachykinin neuropeptides in copper homeostasis in the brain

Lawrence J. Berliner1,2, [email protected], Christopher Jones2. (1) Chemistry and Biochemistry, University of Denver, Centennial, Colorado, United States (2) Science and Health, University Western Sydney, Parramatta, New South Wales, Australia

There is evidence that the tachykinin neuropeptide, neurokinin B (NKB) can bind copper in various valence states and restrict metal ion uptake into astrocytes and is possibly involved in copper homeostasis in the extracellular, synaptic space. A peptide fulfilling this role must be able to bind with an affinity that inhibits interaction with undesirable proteins and peptides, such as Alzheimer’s Aβ-peptides. The metal ion complexes must exist in vivo and their loss would result in abnormal copper levels in the brain. We are investigating whether tachykinins can form copper complexes in vivo and their loss results in disrupted copper levels in the brain. We are synthesizing spin labeled tachykinin mutant NKB peptides for eventual in vivo 3D spatial and 4D spectral-spatial EPR imaging. The mutants have a cysteine in various positions in the peptide, where the thiol specific spin label MTSL (S-(2,2,5,5-tetramethyl-2,5-dihydro-1H-pyrrol-3-yl)methyl methane-sulfonothioate) can be attached. While useful for in-situ solution experiments,

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these aminoxyl (nitroxide) radicals have a ca. 0.5 – 1G or larger linewidth where their efficacy in imaging experiments is limited. The use of trityl (tri-phenylmethyl radicals, on the other hand, have very narrow linewidths (~100mG or less), which increases sensitivity and resolution to levels that compete with conventional MRI. Future plans with each mutant is to assess that both the Cu(I) and Cu(II) binding sites are identical to those of the wild-type tachykinin complexes. The presence of a paramagnetic copper centre will produce a dipole-dipole coupled CuII-nitroxide CW EPR spectrum. By varying the position (6,7,8 or 9) of the nitroxide we can optimise the dipole-dipole coupling to ensure weak isotropic exchange coupling. The observation of weak exchange/dipole-dipole coupling between the metal ion and spin label, allow to determination of peptide binding to Cu(II) in vivo. This project promises to provide the first evidence that copper-tachykinin complexes exist in vivo.

RMRM 146

Supported Tubulated Bilayers (STuBs): an experimental platform for monitoring protein-mediated membrane remodeling

Jefferson D. Knight1, [email protected], Peter Dahl2, Noah Schenk2, Alexandra Ranski2, Michael Hanna3, Anjon Audhya3, Arun Anantharam2. (1) Chemistry, University of Colorado Denver, Denver, Colorado, United States (2) Pharmacology, University of Michigan, Ann Arbor, Michigan, United States (3) Biomolecular Chemistry, University of Wisconsin-Madison School of Medicine, Madison, Wisconsin, United States

Fusion and fission of cellular membranes involve dramatic, precisely regulated changes in membrane curvature mediated by a number of proteins whose mechanisms are not well understood. Despite several recent advances, current methods for investigating curvature sensing and generation in real time using well-controlled systems remain limited. We have developed a novel system based on supported lipid bilayers (SLBs) in which high ionic strength during lipid bilayer deposition results in incorporation of excess lipids in the bilayer, which results in the spontaneous formation of lipid tubules after sequentially washing with water and physiological ionic strength buffer solutions. We find that the process of tubule formation is the result of an ion-dependent spreading of the SLB; addition of a physiological ionic strength buffer solution free of divalent ions leads to expansion of the bilayer and formation of tubules, likely due to increased membrane tension. Conversely, the addition of divalent ions results in contraction of the membrane and a proportional loss of tubules. These ionic conditions can be tuned for each experiment, allowing investigators to control the extent of tubulation. We show the utility of these supported tubulated bilayers, which we term “STuBs,” with an investigation of Sar1, a small Ras family G-protein known to influence membrane curvature. The addition of Sar1 to tubulated bilayers results in both further tubulation and tubule fission, of which fission is shown to be more dominant based on quantification of wide-field fluorescence microscopy images. Individual tubule formation events are observed with polarized total internal reflection fluorescence microscopy (pTIRFM), an imaging method that allows for semi-quantitative measurements of membrane deformations. Overall, STuBs is a simple experimental system, useful for monitoring solute- and protein-mediated effects on membrane topology in aqueous media and in real-time, using widely available instrumentation.

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RMRM 147

Integration of antibacterial ionic liquids/deep eutectic solvents (IL/DES) into electrospun protein-based wound healing scaffolds

Mackenzie J. Harrison3, Tatum A. Bardsley3,5, Paul D. Phillips4,3, [email protected], Joshua R. Greene3, David Fox2, Nathan C. Nieto4, Rico E. Del Sesto1, Robert S. Keller5, Andrew T. Koppisch3, [email protected]. (1) Department of Chemistry, Dixie State University, St. George, Utah, United States (2) Bioscience Division, MS M888, Los Alamos National Laboratory, Los Alamos, New Mexico, United States (3) Department of Chemistry, Northern Arizona University, Flagstaff, Arizona, United States (4) Department of Biology, Northern Arizona University, Flagstaff, Arizona, United States (5) Center for Bioengineering Innovation, Northern Arizona University, Flagstaff, Arizona, United States

Infections to wounds that arise from opportunistic pathogens slow the process of healing and increase the rate of morbidity and mortality to the patient. Bacterial biofilms are responsible for the majority of hospital-acquired infections associated with wounds and surgical incisions. Mature biofilms are characterized in part by a thick layer of exopolymeric material that protects them from their environment, and plays a significant role in the biofilm’s observed recalcitrance towards canonical antibiotic therapy. Our team has developed ionic liquids/deep eutectic solvents (IL/DES) that are demonstrate robust antibacterial activity and are also capable of traversing dermal layers to treat infections that reside within the skin. In this work, antibacterial IL/DES have been integrated into electrospun protein scaffolds that are designed to accelerate the process of wound healing. The scaffolds are fabricated using native skin proteins to affect a close match to the composition and architecture of skin, and are also formulated to contain varying percentages of IL/DES. We observe the IL/DES containing scaffolds to be significantly resistant to corruption by solutions containing several bacterial strains commonly associated with human wounds relative to control scaffolds. Efforts to assess the synergy of the two technologies in the process of wound healing will be discussed.

RMRM 148

Divalent metal cation effects on the membrane binding of the Slp-2 C2A domain

Timothy Spotts1, [email protected], Abena Watson-Siriboe1,2, Jefferson D. Knight1. (1) Chemistry, University of Colorado Denver, Denver, Colorado, United States (2) Integrative Biology, University of Colorado Denver, Denver, Colorado, United States

Synaptotagmins and synaptotagmin-like proteins (Slps) are membrane-binding proteins involved with the cellular process of exocytosis, the release of chemicals and hormones into a cell’s exterior environment. Slp-2 is responsible for docking hormone secretory vesicles to sites of exocytosis in pancreatic cells. Like all Slps, Slp-2 contains an N-terminal Slp-homology domain in addition to two membrane-binding C2 domains (C2A and C2B). The Slp-2 C2A domain has been shown to have a unique response to Ca2+ ions, in that it binds liposome membranes in the absence of Ca2+ but dissociates upon addition of sufficient [Ca2+]. This is in contrast to most C2 domains, which typically bind lipid membranes in either a Ca2+-dependent or Ca2+-independent fashion. To investigate the mechanism of Ca2+-inhibited binding, fluorescence spectroscopy was used to quantify the effect of Ca2+ on binding to liposomes with several physiologically relevant lipid compositions. Next, Slp-2 C2A binding kinetics were used to quantify the affinity of the protein for each membrane

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composition. Competition-based assays were used to determine the ability of other metal ions to bind the protein and inhibit lipid docking, including Mn2+ and Mg2+. Preliminary data support a combination of metal-dependent effects on protein and lipids as the origin of calcium-inhibited membrane binding. Future studies are planned to probe the structural mechanism of this unusual protein-membrane interaction.

RMRM 149

Calcium binding to C2B domains of Synaptotagmin 1, Synaptotagmin 7, and chimeric Synaptotagmin 1/7: A computational study

Nara Chon, [email protected], Sherleen Tran, Jefferson D. Knight, Hai Lin. University of Colorado Denver, Denver, Colorado, United States

The Synaptotagmin (Syt) protein family docks to membranes and is involved in many physiological functions, e.g. the release of hormones and neurotransmitters through exocytosis. Syt1 and Syt7 are two members of this family, and they display significantly different membrane-docking characteristics despite structural similarity. For example, the C2B domains of these two proteins have > 50 % of the identical amino acids in the sequences but bind 2 and 3 calcium ions, respectively. Here, we perform atomistic molecular dynamic simulations for the C2B domains of the wild-type (WT) Syt1, the WT Syt7, and a chimeric (CH) Syt1/7; the chimera is a hybrid of the Syt1 “body” (the beta sheets and alpha helices) and the Syt7 “legs” (calcium binding loops). Strikingly, our simulation results show that the CH Syt1/7 only holds 2 calcium ions tightly, with the 3rd calcium ion hanging loosely, even though we start the simulations from a Syt7-like binding geometry where all 3 calcium ions are tightly bound. The data suggest that calcium binding to C2B is influenced by more than just the calcium-binding loops. Our findings imply that CH Syt1/7 behaves similarly to the WT Syt1 rather than to the WT Syt7 in calcium-activated membrane docking.

Chimeric C2B domain of Syt1/7 in 0.15 M KCl. The Syt1 “body” is shown in gray, the Syt7 “legs" are in orange, and three calcium ions in the binding site are represented as blue spheres.

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RMRM 150

Investigations into the scope, efficacy and antimicrobial mechanism of the broad-spectrum antiseptic choline geranate deep eutectic solvent

Joshua R. Greene4, [email protected], Kahla Merrett4, Lucas F. Simmons4, Alexanndra J. Heyert4, Camille M. Migliori1, Rebeca S. Castro2, Michael Zakrewsky5, Samir Mitragotri5, Joseph L. Baker2, David Fox3, Gerrick E. Lindberg4, Rico E. Del Sesto1, Andrew T. Koppisch4, [email protected]. (1) Department of Chemistry, Dixie State University, St. George, Utah, United States (2) Chemistry, The College of New Jersey, Ewing, New Jersey, United States (3) Bioscience Division, MS M888, Los Alamos National Laboratory, Los Alamos, New Mexico, United States (4) Department of Chemistry, Northern Arizona University, Flagstaff, Arizona, United States (5) Chemical Engineering, University of California, Santa Barbara, Santa Barbara, California, United States

The development of new antibacterial compounds is imperative given the emergence of pathogenic organisms that are resistant to commonly prescribed drugs. Choline Geranate (CAGE) is a deep eutectic solvent that displays broad-spectrum antiseptic activity against planktonic bacteria as well as potent antibiofilm activity. CAGE is capable of penetrating skin after a topical application and retains its antibacterial activity within the dermis, thus showing promising attributes for use of the material both as an antiseptic to disinfect the surface of skin and to combat infections within the underlying tissue. In this work, we have examined the potency of CAGE against mature biofilms of numerous strains commonly associated with skin/wound infections, including several multi-drug resistant organisms. CAGE exhibited significant antibiofilm activity against the panel with typical minimum biofilm eradication concentrations (MBEC) ranging from 1.25-10% (v:v) for most strains. Time-kill assays against mature biofilms of Staphylococcus aureus showed that even short exposures (30 minutes) of dilute CAGE (1% v:v) resulted in a reduction of viable cells within the biofilms by 99% or more. While some ionic liquids/deep eutectic solvents are capable of disrupting recalcitrant biopolymers (such as the protective exopolymeric layer of bacterial biofilms), molecular modeling simulations have provided atomic-level insights into the observed antibacterial effect of CAGE. The simulations of model bacterial lipid membranes reveal that geranate and geranic acid embed in the membrane, while choline is primarily in the aqueous phase. The presence of CAGE components in the membrane results in a dramatic decrease in lipid tail order and induces thinning of the membrane as the concentration of CAGE increases.

RMRM 151

Development of reversible thiol-ene bioconjugation for dynamic protein immobilization to hydrogels

Joseph C. Grim, [email protected], Kristi S. Anseth. Univ of Colorado, Boulder, Colorado, United States

Hydrogels have emerged as promising platforms for culturing cells in vitro because their mechanical and biochemical properties closely mimic native extracellular matrix (ECM). One method to impart biological activity into hydrogels is to covalently tether biomolecules to the hydrogel network. For example, the pendant peptide RGDS derived from fibronectin is ubiquitious in cell culture due to its ability to facilitate cell adhesion to hydrogels. While this approach is commonplace for peptides, proteins (such as growth factors and cytokines) are primarily added

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solubly to culture media. Increasing evidence suggests that the context in which proteins are presented to cells (e.g, as soluble verses tethered siganls) can influence their bioactivity. Indeed, many proteins are bound to the ECM in vivo suggesting cells frequently interact with immobilized proteins via the ECM. By covalently tethering proteins to hydrogels, one can recapitulate protein-ECM interactions in vitro. Thiol-ene click chemistry is a powerful methodology to achieve biomolecule immobilization within hydrogels because it is bioorthogonal. Additionally, since it is a light-mediated process, biomolecules can be immobilized with spatial control. Still, the thiol-ene reaction is irreversible, so it is not possible to release the tethered biomolecule or exchange it with a new biomolecule once immobilization has occurred. To this end, we identified an allyl sulfide functionality that allows for reversible thiol-ene chemistry. Previously, we have employed this methodology to achieve reversible thiol-ene-mediated immobilization of peptides in hydrogels. The focus of this work has expanded this approach to achieve reversible protein immobilization. Specifically, we have employed strain-promoted azide-alkyne cycloaddition polymerization to generate hydrogels that contain pendant allyl sulfide functionality. We have successfully immobilied proteins within these hydrogels using the allyl sulfide moeity and then subsequently released them on-demand. This approach can be repeated multiple times. We also demonstrated that protein tethering and release can be performed in situ with minimal cytotoxic effects to control cellular function. These data demonstrate that the allyl sulfide handle enables reversible protein tethering within hydrogels.

RMRM 152

Colorado State University – Pueblo’s Communities for Building Active Stem Engagement (CBASE) program and research communities

Jillian Manikoff2, [email protected], Daniel T. Conroy2,1, [email protected], Abby Davidson1, Matt A. Cranswick2. (1) Science Learning Center, Colorado State University - Pueblo, Pueblo, Colorado, United States (2) Department of Chemistry, Colorado State University - Pueblo, Pueblo, Colorado, United States

Although interest in pursuing STEM degree programs is high among undergraduate students, only a fraction of those students successfully complete these degrees. Furthermore, underrepresented populations have even lower participation and completion rates in STEM fields. Another prevalent issue for students enrolled in STEM degree programs results from a lack of professional development during the undergraduate experience. As a result undergraduates often graduate without having acquired valuable research and mentorship skills desired by employers, and this leads to STEM graduates entering the job market without the experience needed to acquire career related occupations. Through a five-year Title III Department of Education grant, Colorado State University – Pueblo has initiated the Communities for Building Active Stem Engagement (CBASE) program which aims to address these deficiencies by increasing retention and graduation rates in underrepresented populations, and fostering communities to develop professional skills needed for success beyond the undergraduate experience. CBASE has established research specific communities in Biology, Chemistry, and Engineering. The Chemistry Research Community allows undergraduates, at early stages of their academic career, to gain valuable research experience as Research Interns and later, provides these students with experience in mentoring as Research Fellows. Throughout the program, Research Interns are challenged to think critically in an environment that applies knowledge acquired in classroom and pedagogic lab settings. The program provides all participating students with valuable presentation experience, lab techniques, data analysis, and independent working experience. Through CBASE participation, students are

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expected to have higher retention, graduation, and employment rates. The intent of this poster is to discuss a potentially novel program and methods of refining the program so that this framework may be applied at other universities for improved graduate success.

RMRM 153

Get involved with the ACS Division of Chemical Education

Matthew A. Horn, [email protected]. Dept. of Chemistry, Utah Valley University, Orem, Utah, United States

Want to know more about the Division of Chemical Education, learn how you can get more involved with DivCHED, learn about educational resources for chemistry, find out how to apply for travel awards, or meet and network with people from your region, nationally, and around the world who have similar interests? The Division of Chemical Education aims to serve as a means of focusing and enhancing the interest and efforts of all constituencies involved in the teaching and learning of chemistry at every level. If you have an interest in chemistry education, we want you involved in DivCHED. Come visit our poster to learn more about the Division and all we have to offer, meet representatives from the Division, and let us know what you think the Division can do to better meet the needs of our members.

RMRM 154

NTS – New SI unit definitions

Michael D. Mosher1, [email protected], Robert A. Yokley2, H N. Cheng3. (1) Dept Chemistry Biochemistry, University of Northern Colorado, Greeley, Colorado, United States (2) Analytical Chemistry Consulting Service, LLC, Kernersville, North Carolina, United States (3) USDA Agricultural Research Service, New Orleans, Louisiana, United States

Nomenclature is essential in chemistry in order to provide specific, unambiguous and logical names for chemical elements or compounds. It is part of the language of science and is needed everywhere for research, communication, publication, and instruction. The ACS Committee on Nomenclature, Terminology and Symbols (NTS) is the ACS governance entity that deals with this topic. NTS monitors developments in nomenclature, terminology and symbols, coordinates nomenclature-related activities with other ACS entities, liaises with non-Society organizations, and serves as a resource in matters related to chemistry nomenclature. The redefinition of SI units for the kilogram, ampere, kelvin, and mole is of interest to NTS and chemists worldwide. The new proposed definitions have important ramifications to the practice of chemistry, particularly with respect to our understanding of the base units, to publications within the field, and to the teaching of chemistry. NTS is supplying input to the ongoing discussions and will provide an update in this presentation on the latest developments.

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RMRM 155

Developing electrophilic fluorination experiments for the undergraduate organic chemistry laboratory

Jade Garcia1, [email protected], Melvin L. Druelinger2, David L. Dillon2. (1) Centennial High School, Pueblo, Colorado, United States (2) Chemistry Department, Colorado State University - Pueblo, Pueblo, Colorado, United States

While electrophilic reactions, including electrophilic aromatic substitutions, are common undergraduate organic laboratory experiments, to our knowledge the use of fluorine as the electrophile in the undergraduate laboratory has not been studied. To incorporate this interesting, and somewhat unexpected reaction (electrophilic fluorine???) into the undergraduate curriculum, we have explored the reactions of electrophilic fluorine (using F-TEDA, SelectfluorTM, as the electrophilic fluorine donor) with several substrates. The reaction of indene with F-TEDA gave a fluoroamide; the reaction of anisole and of acetanilide with F-TEDA gave the expected products of electrophilic aromatic substitution. The use of traditional reflux (hot plate) and microwave techniques were both used for these reactions.

RMRM 156

3-D chemistry exercises utilizing Virtual Reality technology

Benjamin Whaley3, [email protected], Arick Sweitzer1, Richard M. Hyslop1, Corina E. Brown2. (1) Univ of Northern Colorado, Greeley, Colorado, United States (2) Chemitry and Biochemitry, Univ. of Northern CO, Greeley, Colorado, United States (3) Chemistry, University of Northern Colorado, Greeley, Colorado, United States

Virtual Reality (VR) technology has been successfully used in training students in the medical and military fields. This research explores the use and the impact of virtual reality (VR) technology on the student’s ability to visualize, conceptually understand, and become more engaged with concepts in a chemistry course. The exploration of VR technology as an active learning tool will be a novel approach in the chemistry classroom and laboratory. With the advent of virtual reality equipment it is possible to bring a new medium to the field of chemical education, one which not only allows for a new take on understanding the geometric and spatial properties of chemistry, but also will bring a new level of excitement and interest in learning chemistry. This presentation reports on several VR exercises developed and tested with students, and implications for teaching.

RMRM 157

Development of a rubric to facilitate improvement in students’ molecular mechanisms in chemistry research papers

Andrew C. Millar, [email protected], Karen J. Knaus. Chemistry, University of Colorado Denver, Denver, Colorado, United States

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The development of a rubric to help students improve research papers in a chemistry course is described in this paper. The instrument proved useful in helping students improve their thinking processes through iterative cycles of rubric use. Instrument reliability and validity were established by inter-rater reliability statistics and ANOVA tests using data collected from students and faculty. The rubric was used to collect student judgments about how well chemistry content knowledge was integrated into the research papers. The project serves as an example where perceptions were used to drive the process of metacognitive evaluation of chemistry research papers. As the quality of student papers improved, the level of inter-rater agreement increased in most areas. In addition, it appears that inter-rater agreement was greater in chemistry content areas in which students had completed more chemistry courses prior to taking the current course; furthermore, prior knowledge seemed to play a role in students’ metacognitive evaluations.

RMRM 158

Systematic approach to teaching NMR analysis in undergraduate organic laboratories

Stephanie Jensen1, [email protected], Jonathan Cook2, Chad Magee1, Susan M. Schelble2. (1) Metropolitan State University of Denver, Northglenn, Colorado, United States (2) Campus Box 52, Metropolitan State University of Denver, Denver, Colorado, United States

Nuclear Magnetic Resonance (NMR) is an widely used tool for structural analysis. Experience in the academic setting is necessary for developing adequate interpretations of spectra. This is an area which undergraduate students commonly encounter difficulty. A systematic approach is introduced to provide an architecture for analysis. Students are to be capable of spectral analysis with minimal guidance. Teaching these basic steps to a student in their infancy will help facilitate quicker acquisition and understanding. The steps that are utilized in Carbon 13 (C13) and Proton NMR (1H NMR), are to count environments, knowing what shielding is, understanding where solvents typically present, how to identify impurities and mixtures, and where functional groups typically appear. Common student misconceptions regarding NMR will be addressed. Students participating will demonstrate enhanced NMR reading and problem solving skills to harness throughout their chemical careers.

RMRM 159

Lengthening Fe(II) MLCT excited-state lifetimes by accessing the high-spin manifold using a tunable ligand framework

Steven M. Fatur, [email protected], Samuel G. Shepard, Niels H. Damrauer. Department of Chemistry, University of Colorado at Boulder, Boulder, Colorado, United States

Many transition metal photocatalysts utilize a highly energetic, long-lived metal-to-ligand charge transfer (MLCT) state as the catalytically active state. However, earth-abundant first row analogues of successful Ru(II) and Ir(III) photocatalysts, especially Fe(II), are plagued by ultrafast relaxation because the decreased ligand-field splitting opens new relaxation pathways via low-lying metal-centered states. In designing potential photocatalysts with Fe(II) centers, we chose to exploit the decreased ligand-field splitting by destabilizing the singlet state until the lowest energy quintet state replaced it as the ground state. This opens up a distinct dynamical picture and lengthens the MLCT

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excited-state lifetime. Generally, this class of complexes displays a > 100-fold improvement relative to the ~100 fs MLCT lifetime of the low-spin parent, Fe(II) bis-terpyridine. This is accomplished using a sterically demanding bis-terpyridyl framework in which the halogens of one ligand repel the other. Furthermore, the ligand framework is easily altered synthetically, allowing for independent tunability by changing the halogen (X) or the 4’-substituent (R) to explore steric phenomena or electronic effects, respectively. We have investigated a range of these compounds using a variety of methods including x-ray diffraction, electrochemistry, density functional theory, and transient absorption spectroscopy. Through this effort, we highlight a novel approach to controlling excited state dynamics.

RMRM 160

Pd solubility in transition metal carbides for the methanol oxidation reaction

James M. Thode2, [email protected], Brian M. Leonard1. (1) Dept 3838, UWY Chemistry, Laramie, Wyoming, United States (2) Chemistry, University of Wyoming, Laramie, Wyoming, United States

Transition metal carbides (TMCs) are a group of materials with exciting refractory and catalytic properties. The last 40+ years have revealed a multitude of compounds with emergent characteristics. Chromium carbide and titanium carbide are seen throughout industry, in part, due to their exceptional mechanical stability. Chromium is corrosion resistant while titanium is also very light. Carbide of molybdenum and tungsten have been shown to be effective support materials in fuel cell chemistry. In particular, Pt group metals (PGMs) are good catalysts and when supported on carbides show enhanced reactivity. However PGMs do not form carbides themselves and have very limited solubility in bimetallic carbides. Here, we report new information with respect to the solubility of PGMs in group 6 TMCs. By investigating the formation of AN oxide amine precursor, we have unraveled several key criteria that have enabled the synthesis of these bimetallic compounds with greatly enhanced solubility. We have identified modified synthesis methods that manipulate reaction pH in order to produce a series of new compounds. In addition, our materials demonstrate promising catalytic activity for the methanol oxidation reaction.

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RMRM 161

Crystalline Co3O4 nanoparticle synthesis and the role of alcohol solvents: Evidence for a wholly kinetic, and not a surface ligand thermodynamic, alcohol solvent effect

Scott Folkman2, [email protected], Meng Zhou3, Matthew Nicki2, Richard G. Finke1. (1) Colorado State Univ, Fort Collins, Colorado, United States (2) Chemistry, Colorado State University, Fort Collins, Colorado, United States (3) Department of Natural Sciences, Lawrence Technological University, Southfield, Michigan, United States

Crystalline metal-oxide nanoparticles, such as spinel phase Co3O4, are important materials for sensors, photonics, and catalysis, among other uses. The characteristics and utility of metal-oxide nanomaterials are determined by their size, polydispersity, crystal structure, and any surface ligands. The most convenient method to tune metal-oxide nanoparticle properties is through their solution-based synthesis. Herein, we present a procedure for the synthesis of spinel phase Co3O4 nanoparticles in solution starting with Co(OAc)2 and NH4OH in either ethanol or water with O2 bubbling at 75° C. The particles are characterized using FT-IR, PXRD, elemental analysis, HR-TEM, and SAED. The particles synthesized in ethanol yielded crystalline Co3O4 nanoparticles, 3 ± 1 nm, whereas the particles synthesized in water gave mixed-phase particles with a broad size range (14-400 nm)—revealing the critical importance of the solvent. The solvent could be acting in one or more of two limiting regimes: kinetically (e.g., affecting the speciation of the Co(II) precursor to the particle’s nucleation and growth) or thermodynamically (e.g., as a surface ligand). In order to differentiate the two possible effects, we used a reductive dissolution method to digest the particles and liberate any surface ligands. Quantitative 1H NMR was then used to identify acetate as the only detectable surface ligand—that is, EtOH is absent as a surface ligand. Evidence is also presented for the binding mode and surface coverage of the acetate-terminated Co3O4 nanoparticles. The findings of this study provide the first precedent that the profound effect of alcohol solvents on metal-oxide nanoparticle formation reactions, seen herein and in the literature, may more generally be operating though a kinetic and mechanistic effect, not a surface ligand effect as previously believed. The results provide precedent for the rational fine tuning of metal-oxide nanoparticles and their properties through kinetically controlled syntheses.

RMRM 162

Exploring and mitigating failure modes in electrodeposited Cu-Sb anodes for Li-ion batteries

Maxwell Schulze1, [email protected], Amy L. Prieto2. (1) Colorado State University, Colorado, Colorado, United States (2) Chemistry Department C210, Colorado State University, Fort Collins, Colorado, United States

Next generation rechargable batteries for electric vehicle and grid energy storage applications require long cycle lifetimes and greater energy densities than tradition intercalation Li-ion batteries. Replacing graphite with alloy anodes shows promise for increasing the lithium storage capacity of batteries, though the anodes still suffer from limited cycle lifetimes. Mechanical instability and formation of a surface-electrolyte-interface layer both contribute to the limited cycle lifetimes of alloy anodes. Building off the promising behavior of Cu2Sb alloy anodes for Li-ion batteries, we show how cycle lifetimes of electrodeposited Cu-Sb thin-films can be further improved by compositional tuning of the deposited films, and by controlling undesirable mechano-chemical interactions at the film-substrate interface.

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RMRM 163

Analysis of bulk and surface properties of catalytically-active nickel carbide/nitride nanostructures using X-ray techniques

Samuel Gage2, [email protected], Chilan Ngo2, Sarah Shulda2, Christopher Tassone3, Dennis Nordlund3, Svitlana Pylypenko2, Ryan M. Richards1. (1) Chemistry and Geochemistry, Colorado School of Mines, Golden, Colorado, United States (2) Chemistry, Colorado School of Mines, Golden, Colorado, United States (3) SLAC National Accelerator Laboratory, Menlo Park, California, United States

Transition metal carbides and nitrides are an ever-growing topic in the scientific community. These materials can be synthesized with varying composition and morphology to exhibit properties similar to platinum-group metal catalysts, which are relevant to industrial heterogeneous catalysis and energy development. Studies, which report promising catalytic performances of nickel carbide and nitride catalysts, have continued to increase in recent years. Wet-chemical approaches involving a top-down thermal decomposition of nickel salt precursors in the presence of product-directing solvents are particularly interesting. The degree of nitrogen present in the nickel salt precursor, as well as the choice of molecular ligand-based solvents, can influence the material properties of the nickel carbide/nitride (Ni3C/Ni3N) products. A series of nitrogen-rich and nitrogen-poor nickel salt precursors were thermally degraded in the presence of oleylamine. X-ray diffraction confirms the bulk hexagonal crystal structure belonging to Ni3C/Ni3N. However, a combination of bulk and surface X-ray characterization techniques, including the X-ray photoelectron spectroscopy (XPS), X-ray absorption near edge structure (XANES), extended X-ray absorption fine structure (EXAFS), small angle- and wide angle X-ray scattering (SAXS and WAXS) indicate that the material properties of the Ni3C/Ni3N nanostructures do vary depending on the precursor. Batch reactor hydrogenation reactions of unsaturated model reactants were performed, in order to correlate the structure-property relationships to catalytic activity. This work elucidates how wet chemical bottom-up approaches to synthesis affect the material properties of Ni3C/Ni3N nanostructures and how effective these materials are in catalysis relevant to industrial- and energy-related processes.

RMRM 164

Substituent effects on the HOMO-LUMO absorption and emission of Pt(II)-biphenyl complexes containing 1,10-phenanthroline derivatives

Arvin J. Cruz, [email protected]. Chemistry, Fort Hays State University, Hays, Kansas, United States

Eight platinum(II) biphenyl complexes containing 1,10-phenanthroline derivatives were synthesized and their physical and photophysical properties were examined. X-ray crystal structures were obtained for five of the complexes with two different motifs giving rise to two different circular dichroism spectra. Structures obtained by density functional theory were in agreement with the parameters obtained by x-ray diffraction. Electron density of the HOMO is located on the metal

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center and the biphenyl ligand; for the LUMO it is located primarily on the phenanthroline ligand. The results for time dependent density functional theory calculations are in agreement with a MLCT (metal-to-ligand charge transfer) low energy electronic transition assignment. The optical, emission and reduction potentials correlated with Hammett-Sigma functions giving rise to excellent free-energy correlations for the series of complexes.

RMRM 165

Bulky β-diketones enable new Lewis acidic ligand platform

Michael P. Marshak, [email protected]. Chemistry and Biochemistry, University of Colorado Boulder, Boulder, Colorado, United States

The ability to limit the coordination of β-diketonates on metal complexes is demonstrated for the first time, providing a chemically robust and coordinatively versatile platform for mechanistic investigations, metal functionalization, and improved catalyst design.

RMRM 166

Inorganic-organic hybrid material for the cyanide sensing using Co(II)-bis-terpyridine complexes

Indrani Bhowmick, [email protected], Cameron Collins, Jennifer Maughan. Colorado State University Pueblo, Pueblo, Colorado, United States

Cyanide(CN-) in aqueous media is a threat to the environment. Our goal is to use 3D metal complexes to selectively detect cyanide colorimetrically in aqueous media in order to achieve a more cost effective and environmentally friendly method. Our research showed Co(II)-bis-terpyridine complexes could be used for the naked-eye detection of CN- in water in 10-6 M level.[1] We can also successfully identify the post detection product which is very important to find proper environment friendly disposal of degrades. Our current goal is to make hybrid materials by immobilizing similar Co(II)-bis-terpyridine complexes on a solid surface like cellulose/Silica/TiO2-thin film and use as surface-based cyanide sensor. The surface based sensors provides a better portability and disposal of the sensor materials. In addition we are attempting to apply similar methodology to detect organophosphates using the inorganic-organic hybrid materials.

Aqueous solution of Co(II)-bis-terpyridine complexes changes color in presence of CN-. Our current goal is to immobilize the similar complexes on a solid surface with suitable modification of the terpyridine ligands.

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RMRM 167

Hot injection synthesis and stacking of p-type solar absorbing Cu3SbSe3 nanodiscs

Dan Agocs1, [email protected], Amy L. Prieto2. (1) Colorado State University, Fort Collins, Colorado, United States (2) Chemistry Department C210, Colorado State University, Fort Collins, Colorado, United States

Currently, the best thin-film photovoltaic absorber materials are CdTe and Cu(In,Ga)Se2 (CIGS). These materials have each been utilized in modules with power conversion efficiencies greater than 20%, but suffer the impracticality of rare and/or toxic constituent elements which may suppress widespread implementation of solar cells fabricated using these materials. Alternative earth-abundant materials such as Cu2ZnSnS4 (CZTS) have been investigated, and have achieved power conversion efficiencies up to 12.6%, but are limited by low open-circuit potentials, likely caused by cation disorder in this complex system. Other earth-abundant systems have been proposed, using copper metal chalcogenides of the form Cu-III-VI to mimic the success of CuInSe2, but these systems have not been thoroughly characterized as of yet. Our work has explored a solution-phase synthesis of Cu3SbSe3 nanodiscs and their preliminary characterization for photovoltaic applications. We have determined a set of conditions for a relatively robust synthesis, and analyzed the effects of temperature, stoichiometry, and coordinating ligands on the products of our chosen hot injection route. Initial optical and electronic properties are reported, as well as the effects of organic media on particle morphology. We find strong p-type absorber characteristics, though the band gap may be too large for solar cell application. We also propose a method to retain cheap solution processability while attempting to achieve a larger effective crystallite size than is normally attained in these nanoscale system with the hope that this work may contribute to minimizing grain boundary recombination losses in similar photovoltaic materials.

RMRM 168

Comparison of the surface electrolyte interface from sodium and lithium ion batteries on copper antiminide electrodes

Nathan J. Gimble1, [email protected], Amy L. Prieto2. (1) Chemistry, Colorado State University, Fort Collins, Colorado, United States (2) Chemistry Department C210, Colorado State University, Fort Collins, Colorado, United States

Next generation battery technology is at the forefront of materials chemistry. Lithium ion batteries (LIB) are an excellent chemical storage system, but due to its expense, the similar chemistry of a sodium ion battery (NIB) system offers a more economical alternative in situations where the size of the battery is not a factor. Copper antimonide has shown to be an effective lithium alloy material to study, and using electrodeposition, the material can be studied directly without binders. A potential failure mechanism for alloy materials is through unrestricted growth of the surface electrolyte interface (SEI) resulting from the reduction of the electrolyte onto the anode material. The SEI has been studied extensively on graphite however it has been discovered that the same electrolyte additives increase the cycle life of alloy materials. It is however, unknown why different electrolytes can extend the lifetime of the battery. Xray photoelectron spectroscopy (XPS) is an analytical method employed to study the SEI due to its surface sensitivity. Very few studies have been published examining the difference between a SEI formed from a LIB and one formed from a NIB

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with no other variables changed. XPS data of SEI’s formed from LIB and NIB will be compared to gain a greater understand of the SEI.

RMRM 169

Developing a solution phase synthetic route to Cu2SiSe3: An earth abundent photovoltaic material

Lily J. Moloney, [email protected], Amy L. Prieto. Chemistry, Colorado State University, Fort Collins, Colorado, United States

Photovoltaics have the ability to offer clean energy alternatives to burning fossil fuels but to compete with fossil fuels, the solar cell materials and design need to be cost effective and scalable. Improved costs and high theoretical efficiencies translate into potential commercial use of second generation cells, including CdTe, and CuIn1-xGaxSe2. Yet because these compounds use elements that are rare and expensive, their commercial viability remains low. According to the Shockley-Queisser equation, ideal candidates for high efficiency solar cells would have direct band gaps around 1.4 eV. The compound Cu2SiSe3 is predicted to have a direct band gap of 1.34 eV and is composed of all environmentally friendly, earth abundant elements. Previous syntheses require high reaction temperatures and limited experimental research on the properties of Cu2SiSe3 for applications in photovoltaics have been reported. The work presented here shows the development of a low temperature solution phase synthetic route to Cu2SiSe3 as a new thin film solar cell material.

RMRM 170

Organic-inorganic nano hybrid catalyst for slurry phase residue hydrocracking

Ravindra Prajapati, [email protected]. Heavy oil upgrading, CSIR-Indian Institute of Petroleum, DEHRADUN, Uttarakhand, India

The drastic increasing demand of transportation fuel can be fulfilled by upgrading low valued heavy oil and residue (1). In the past few years, slurry phase hydrocracking becomes important subject for researchers to upgrade vacuum residues (2). The slurry phase catalyst is broadly divided into heterogeneous solid powder, homogeneous oil soluble and water soluble catalysts. In this direction we have prepared organic-inorganic hybrid catalyst at supercritical conditions. For this preparation, Mo and Ni based precursors and organic modifier are used. Hydroprocessing activity of the hybrid catalysts was examined in high temperature and high pressure batch reactor. The effect of molar concentrations of modifier on residue conversion is also studied. The catalysts are characterized by TEM, SEM, XRD, CV, FT-IR and TGA. These characterizations confirm that the organic-inorganic fused catalysts are nano in size where active metal and promoter are located at the core of the organic matrix. The hydrotreating activities like hydrodesulfurization (HDS), hydrodemetallization (HDM), MCR conversion and asphaltene conversion (HDAs) of vacuum residue are measured on five catalysts. The catalyst having 4M of modifier shows high residue conversion (3). The product distribution is presented in Fig 1. The catalyst 2M has higher Vacuum gas oil (VGO) fraction, 4M has higher naphtha and gas oil fraction whereas the production of coke is high in 3M.

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Product distribution of liquid product

RMRM 171

Selective β C-H mono- and di- halogenation of alcohols via radical relay chaperones

Avassaya Vanitcha, [email protected]. Chemistry & Biochemistry, The Ohio State University, Columbus, Ohio, United States

A radical-mediated strategy for selective β C−H halogenation of alcohols was achieved via a radical relay chaperone strategy. This approach employs an imidate radical capable of performing a 1,5-hydrogen atom transfer (HAT) and enables mono- and di-halogenations at the β carbon of alcohols by using simple iodide, bromide, and chloride salts. This imidate chaperone developed by our group is installed in a single step and provides controllable selectivity to functionalize unactivated C-H bonds even in the presence of weaker bonds. Notably, this chaperone design employs a non-nucleophilic nitrogen atom capable of performing multiple HATs instead of the typical nucleophilic substitution observed in N-centered radical oxidations. Our streamlined protocol converts alcohols to mono- and di- haloimidates, which following hydrolysis reveals β-halogenated alcohol analogs. Further manipulation of the geminal diiodide allows access to medicinally relevant di-fluoro and deutero derivatives.

RMRM 172

Spectroscopic properties of imidazolium based room temperature ionic liquids

Brian D. Etz2, [email protected], Natalie Losada2, Timothy Schutt1, Shubham Vyas2. (1) Chemical and Biological Engineering, Colorado School of Mines, Wheatridge, Colorado, United States (2) Chemistry, Colorado School of Mines, Golden, Colorado, United States

Room Temperature Ionic Liquids (RTILs) are of particular interest to a variety of scientific sectors. RTILs are known as “green solvents” and have numerous applications due to their desirable properties: such as low vapor pressure, high boiling point, and high ionic conductivity. Since RTILs have been implicated in several photochemical applications, it is of utmost importance to investigate the spectroscopic properties of RTILs itself. A group of imidazolium containing RTILs with different anions and side chains has been synthesized and analyzed within this study. The

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anions and side chains are known to affect the properties for RTILs such as viscosity, which may have an effect on the spectroscopic characteristics. Electronic structure calculations have been performed in parallel with the synthesis to probe the properties for the RTILs prepared. It has been shown that modeling RTILs is more accurate when using the gas phase calculations as opposed to the implicit solvation. Moreover, Laser Flash Photolysis was performed on the synthesized RTILs to understand how these materials act as solvents with reactive intermediates present. Both computational and experimental findings will be presented in this talk.

RMRM 173

Synthesis of sialyl-Tn (STn) antigens for the development of efficient cancer vaccine

Pitambar Khanal, [email protected], Paul Savage. Chemistry and Biochemistry, Brigham Young University, Provo, Utah, United States

Sialyl-Tn (STn) antigen are expressed in most of the carcinomas and usually absent in healthy tissues. Their limited success in therapeutic vaccination due to low immunogenicity can be overcome by use of novel antigen. New STn antigens are synthesized and reagents being prepared to isolate and characterize antibodies produced in response to vaccination to develop efficient cancer vaccines

RMRM 174

Using chemical principles to imitate and interface with biological systems

Dylan Domaille, [email protected]. Chemistry, Colorado School of Mines, Golden, Colorado, United States

Two-dimensional cell culture — for example, the growth of adherent cells on a glass coverslip — is an indispensible technique in molecular and cell biology. However, the conditions in which these cells are grown differ drastically from the cytoarchitecture the cell experiences in native tissue. The differences in the chemical, physical, and mechanical characteristics of these environments can make it difficult to translate results from cell culture to in vivo systems. Here, we present a synthetic hydrogel material that is capable of mimicing the mechanical properties of native tissue by virtue of its dynamic covalent crosslinking chemistry. Further, we identify the origin of these hydrogel properties with a combination of small molecule kinetic studies that model the crosslinking chemistry and rheological studies of the hydrogel material.

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RMRM 175

Catalytic hydroxylation of polyethylenes

Ala Bunescu2, [email protected], Sunwoo Lee1, Qian Li2, John F. Hartwig2. (1) Chonnam Natl University, Gwangju, Korea (the Republic of) (2) University of California Berkeley, Berkeley, California, United States

Polyolefins account for 60% of global plastic consumption, but many potential applications of polyolefins require that their properties, such as compatibility with polar polymers, adhesion, gas permeability, and surface wetting, be improved. A strategy to overcome these deficiencies would involve the introduction of polar functionalities onto the polymer chain. We developed a Ni-catalyzed hydroxylation of polyethylenes (LDPE, HDPE, and LLDPE) in the presence of mCPBA as an oxidant. Among the nickel catalysts we tested, [Ni(Me4Phen)3](BPh4)2 (Me4Phen = 3,4,7,8,-tetramethyl-1,10-phenanthroline) reacted with the highest turnover number (TON) for hydroxylation of cyclohexane and the highest selectivity for the formation of cyclohexanol over cyclohexanone (TON: 5560, cyclohexanol/(cyclohexanone+ε-caprolactone) ratio: 10.5). The hydroxylation of various polyethylene materials by the combination of [Ni(Me4Phen)3](BPh4)2 and mCPBA led to the introduction of 2.0 to 5.5 functional groups (alcohol, ketone, alkyl chloride) per 100 monomer units with up to 88% selectivity for formation of alcohols over ketones or chloride. The degree of functionalization correlated with the ratio of oxidant to monomer repeat units. This functionalization occurred without significant modification of the molecular weight of polymer that would result from chain cleavage or crosslinking. The selectivity and efficiency of the reactions of polyethylenes conducted in the absence of nickel catalyst were lower than those of reaction conducted in the presence of the nickel catalyst. Moreover, the molecular weights of materials formed by the uncatalyzed oxidations were significantly lower than those of the parent polymer, indicating that chain cleavage occurred during the oxidation reaction. These hydroxylated polyethylenes resulting from the catalytic oxidation process serve as macroinitiators to synthesize graft polycaprolactones that compatibilize polyethylene-polycaprolactone blends.

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RMRM 176

Synthesis and computational analysis of configurationally stable dual domain twistacenes

Jacob A. Weber1, [email protected], Edward L. Clennan2. (1) Chemistry, University of Wyoming, Laramie, Wyoming, United States (2) Department of Chemistry, University of Wyoming, Laramie, Wyoming, United States

Circularly polarized (CP) light is of interest in the fabrication of high efficiency electronic displays. The current method for generating CP light in such devices is to pass plane averaged emission through a series of filters. The filters generate unwanted bulk and reduce the throughput of the CP light. These inadequacies would be immediately resolved with the realization of direct emission of CP light from a circularly polarized organic light emitting diode (CP-OLED). The remarkable electronic properties of acenes have been exploited in the fabrication of high efficiency OLEDs and naturally, twisted acenes are ideal candidates for the fabrication of CP-OLEDs. However, no twisted acene synthesized to date has exhibited a half-life of specific rotation decay greater than several hours at room temperature, excluding their use in the fabrication of CP-OLED devices. We report the synthesis of the first configurationally stable twisted acene. By imbedding anthracene into the structure of [7]helicene at the fulcrum ring, we have generated a twistacene with a longitudinal twist of 22o and a barrier to racemization of 40 kcal/mol, as predicted by quantum chemical calculations.

RMRM 177

Nitration and reduction of pyrazines

Andrew T. McGrath, Allen M. Schoffstall, [email protected]. Department of Chemistry and Biochemistry, University of Colorado Colorado Springs, Colorado Springs, Colorado, United States

Nitration of the phenyl group of tetrasubstituted pyrazines was expected to produce largely m-nitration of the phenyl ring due to the electron withdrawing nature of the pyrazine ring. However, a mixture of isomers was obtained, which still produced a satisfactory yield of the m-nitrophenylpyrazine derivative as the major isomer. The nitro derivative was successfully reduced to a solid hexahydropyrazine for characterization.

RMRM 178

Visible-light promoted C-S bond formation via intermolecular charge-transfer

Bin Liu3, [email protected], Chern-Hooi Lim2, Garret Miyake1. (1) University of Colorado Boulder, Boulder, Colorado, United States (2) Chemical and Biological Engineering, University of Colorado at Boulder, Boulder, Colorado, United States (3) university of colorado boulder, Boulder, Colorado, United States

This presentation will discuss a protocol for the synthesis of C-S bonds via visible-light promoted intermolecular charge-transfer. The reaction is driven by the photochemical activity of in situ generated electron donor/acceptor complexes, formed by the aggregation of thiolates and aryl halides.

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RMRM 179

3D printing polymeric photonic crystals

Bret Boyle, [email protected], Garret Miyake. Chemistry, Colorado State University, Fort Collins, Colorado, United States

Photonic crystals (PCs) are periodic nanostructures in nature used to reflect different wavelengths of light for camouflage, signaling, and heat control. These natural photonic crystals can be mimicked through the self-assembly of block copolymers (BCPs). The challenge of BCP self-assembly to photonic crystals is that chain entanglement often impedes the self-assembly of the BCPs into a periodic structure capable of reflecting visible light. Further, manufacturing capability and cost of artificial photonic crystal productions on scale are major obstacles to broadly implement this technology. To address these concerns, we have developed a dendronized BCP photonic crystal synthesized in a cost-effective fashion and self-assembled into a PC via additive manufacturing with a standard bench-top 3D printer. These polymeric photonic crystals can also be precisely tuned by varying molecular weight to reflect wavelengths of light throughout the visible spectrum.

RMRM 180

Photoinduced organocatalyzed atom transfer radical polymerization using continuous flow reactors

Logan R. Beck2, [email protected], Garret Miyake1. (1) University of Colorado Boulder, Boulder, Colorado, United States (2) Chemistry, University of Colorado Boulder, Boulder, Colorado, United States

Photoinduced organocatalyzed atom transfer radical polymerization (O-ATRP) uses organic photoredox catalysts, requiring uniform irradiation for control over the polymerization reaction. Continuous flow reactors (CFRs) maximize surface area to promote uniform irradiation as well as allow for large volumes of well-defined polymeric materials to be efficiently synthesized. O-ATRP has been adapted to continuous flow using several monomer classes and organic photocatalysts. The improved irradiation also allows for lower catalyst loadings, further promoting CFRs as an efficient method for large scale polymerizations.

RMRM 181

Monitoring Volatile Organic Compounds (VOCs) in real-time on oil and natural gas production sites

Randi C. Lupardus, [email protected], Scott Franklin, David L. Pringle. Univ of Northern Colorado, Greeley, Colorado, United States

Oil and Natural Gas (O&NG) development, production, infrastructure, and associated processing activities can be a substantial source of air pollution, yet relevant data and real-time quantification methods are lacking. In the current study, O&NG fugitive emissions of Volatile Organic Compounds

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(VOCs) were quantified in real-time and used to determine the spatial and temporal windows of exposure for proximate flora and fauna. Eleven O&NG sites on the Pawnee National Grassland in Northeastern Colorado were randomly selected and grouped according to production along with 13 control sites from three geographical locations. At each site, samples were collected 25 m from the wellhead in NE, SE and W directions. In each direction, two samples were collected with a Gasmet DX4040 gas analyzer every hour from 8:00 am to 2:00 pm (6 hours total), July to October, 2016 (N=864). VOC concentrations generally increased during the 6 hr. day with the exception of N2O and were predominately the result of O&NG production and not vehicle exhaust. Thirteen of 24 VOCs had significantly different levels between production groups, frequently above reference standards and at biologically relevant levels for flora and fauna. The most biologically relevant VOCs, found at concentrations exceeding time weighted average permissible exposure limits (TWA PELs), were benzene and acrolein. Generalized Estimating Equations (GEEs) measured the relative quality of statistical models predicting benzene concentrations on sites. The data not only confirms that O&NG emissions are impacting the region, but also that this influence is present at all sites, including controls. Increased real-time VOC monitoring on O&NG sites is required to identify and contain fugitive emissions and to protect human and environmental health.

RMRM 182

Biogeochemical and microbial dynamics of produced water from unconventional wells in the Powder River Basin, Wyoming

Donna L. Drogos1, [email protected], Karen Wawrousek2, Michael Urynowicz1, Charles W. Nye3, Scott A. Quillinan3. (1) Civil Engineering, University of Wyoming, Laramie, Wyoming, United States (2) Chemical Engineering, University of Wyoming, Laramie, Wyoming, United States (3) Carbon Management Institute, University of Wyoming, Laramie, Wyoming, United States

Microbial activity in waters associated with unconventional oil and gas reservoirs can profoundly affect options for treatment, storage, disposal, and reuse of produced water (PW); frac fluid composition; biocide use; near borehole reservoir properties; and microbially induced gas production. Improved identification of microbial communities is required to develop solutions for detrimental microbial activity and to exploit favorable activity. We quantified the microbial communities, inorganic chemistry, and isotopic composition in PW samples from six unconventional oil and gas wells in the Powder River Basin in northeast Wyoming. The wells are horizontal completions in the Frontier, Niobrara, Shannon, and Turner formations at depths of 10,000 to 12,000 feet, with PW temperatures ranging from 93OF to 130OF. Biocides utilized in frac fluids primarily included glutaraldehyde and Alkyl Dimethyl Benzyl Ammonium Chloride (ADBAC) with first production occurring in 2013. Geochemical results for PW are: pH 6.5 to 6.9; alkalinity (as CaCO3) 219 to 519 ppm; salinity 13,200 to 22,300 ppm; and TDS 39,364 to 62,725 ppm. The dHH2O and d18OH2O values of PW samples range from -78.16 to -50.31‰ and -7.10 to 0.81‰ vs. V-SMOW, respectively. The d13CDIC signatures range from -6.87 to 4.72‰ vs. V-PDB, respectively. Illumina MiSeq 16S rRNA sequencing identified the majority of communities in PW are related to anaerobic, thermophilic, halophilic, chemoheterotrophic, and chemoorganotrophic bacteria, including Thermotoga, Clostridiaceae, Thermoanaerobacter, Petrotoga, Anaerobaculum, Clostridiales, Desulfomicrobium, and Halanaerobiaceae. These findings are important for identification of biogeochemical reactions that affect the organic-inorganic-microbial interactions among reservoir rocks, formation waters, and frac fluids. These biogeochemical reactions have implications for the handling and reuse and of frac fluids; determining biocide application; and identifying the potential for biogenic gas production.

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RMRM 183

Microbial community analysis of produced waters from the Green River Basin in Wyoming

Karen Wawrousek2, [email protected], Donna L. Drogos1, Michael Urynowicz1, Charles W. Nye3, Scott A. Quillinan3. (1) Civil Engineering, University Of Wyoming, Laramie, Wyoming, United States (2) Chemical Engineering, University of Wyoming, Laramie, Wyoming, United States (3) Carbon Management Institute, University of Wyoming, Laramie, Wyoming, United States

Despite the prevalence of unconventional natural gas production, little is understood about the downhole microbial ecosystems and how these microbes affect biogeochemical reactions. To better understand this naturally occurring ecosystem, Illumina MiSeq 16S rRNA sequencing has been performed on waters collected from the water-gas separator of five hydraulically fractured wells ranging in depth from approximately 9,500ft to 11,500ft in the Green River Basin in southeast Wyoming. Correlations between pH, salinity, and metals naturally present in the groundwater, as well as biocides used during fracturing and production, were made when analyzing differences in microbial communities. Preliminary results identify several bacterial and archaeal families including: Clostridiales, Thermoanaerobacterales, Synergistales, Alteromonadales, and Thermotogales. Of the 5 sampled wells in the Green River Basin, 16 microbes were identified in all samples. These microbes common to all 5 samples include Anaerobaculum, Thermovirga, and an unclassified Clostridiaceae. Unclassified 16S sequences representing unique unidentified microbes are analyzed for their presence in multiple samples, and microbial populations across wells are analyzed to better understand the microbial communities present in these exotic environments.

RMRM 184

Probing the specific interactions of simple aromatic amides with a reverse micellar interface

Benjamin Peters2, [email protected], Debbie C. Crans1, Dean Crick1, Gabriel Cardiff1. (1) Colorado State University, Fort Collins, Colorado, United States (2) Chemistry, Colorado State University, Fort Collins, Colorado, United States

Simple aromatic amides have been used to treat a variety of diseases, such as tuberculosis. Many simple aromatic amides like nicotinamide and picolinamide have been shown to have anti-tuberculosis activity and are structurally very similar to the first line drug, isoniazid. One of the major differences in the structure of these compounds is the placement of the nitrogen in the pyridine ring, suggesting that the moiety is important for drug efficacy. This study explores how the ring orientation affects the interactions of these compounds with a membrane-like interface. 1H 1D and 2D NMR techniques were used in combination with Na+ Aerosol-OT reverse micelles to determine the specific placement and orientation of isoniazid, isonicotinamide, nicotinamide, picolinamide, and benzamide at the detergent/water interface. It was found that the orientation of the nitrogen in the pyridine relative to that of the amide greatly effects the orientation of the molecules and penetration of the molecules into the membrane-like interface. The results of these experiments show that it is important to think beyond logP values for uptake of compounds into lipid interfaces.

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RMRM 185

Investigating the effects of pyrazinamide and pyrazinoic acid on model membranes

Cameron Van Cleave1, [email protected], John Peter Hough2, Benjamin Peters1, Allison Haase1, Dean Crick3, Debbie C. Crans1,3. (1) Chemistry, Colorado State Univerity, Fort Collins, Colorado, United States (2) Biochemistry, Colorado State University, Fort Collins, Colorado, United States (3) Cell and Molecular Biology, Colorado State University, Fort Collins, Colorado, United States

Current treatments for Mycobacterium tuberculosis infection typically involve a six-month regimen of isoniazid, rifampin, and pyrazinamide. The mechanism of action for pyrazinamide is largely unknown, but it is thought that upon entering M. tuberculosis pyrazinamide is hydrolyzed by pyrazinamidase to its active form, pyrazinoic acid. In this study we test the interactions of pyrazinamide and pyrazinoic acid with reverse micelles and phospholipids monolayers. We used 1D 2D 1H NMR spectroscopy to investigate drug interactions at a water interface within aerosol-OT (AOT) reverse micelles. Compression isotherms of DPPC and DPPE Langmuir films were used to study membrane response to both drugs at varying pHs and drug concentrations. Overall it was found that pyrazinamide was able to penetrate an interface more than pyrazinoic acid and that they both interact with the lipid interface of a membrane.

RMRM 186

Characterization of chitinase activities in copper supplemented Penicillium spinulosum cultures

Brooklynn J. Trujillo2, [email protected], Sandra J. Bonetti1. (1) Colorado State Univ Pueblo, Pueblo, Colorado, United States (2) Chemistry, Colorado State University- Pueblo, PUEBLO, Colorado, United States

Pencillium fungi are known for their production of exocellular cellulases and other glycohydrolases as a means to obtain nutrients for their surroundings. Pencillium spinulosum liquid shake cultures have been found to produce exocellular β-N-acetylglucosaminidases or chitinases, which may participate in digestion of chitin-containing materials such as fungal and yeast cell walls and also insect exoskeletons. Investigations in our laboratory indicate that copper (II) supplementation of the growth media affects exocellular chitinase activity in the media. Our investigations found that a ten-fold increase in copper(II) supplementation of the standard growth (SG) media resulted in enhanced chitinase enzyme activity. Significant activity in High Cu SG media was observed on Day 9 to Day 20 after inoculation ranging from a minimum of 0.15 U/mL to a maximum of 0.93 U/mL; activity in the SG media was observed on Day 7 to Day 20 after inoculation ranging from a minimum of 0.02 U/mL to a maximum of 0.33 U/mL. The highest chitinase activities on Day 16 was observed in High Cu SG media whose magnitude is 3.88 higher than that observed in SG media. The second highest peak was at Day 19, 0.82 U/mL in High Cu SG media, which was 2.65 magnitude higher than in SG media.

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RMRM 187

Synthesis of a fully saturated menaquinone analog, menaquinone-2 (I,II-H2) and investigation of its interaction with a reverse micelle model membrane interface

Emma A. Gubler2, [email protected], Jordan T. Koehn2, Dean C. Crick3, Debbie C. Crans1. (1) Colorado State University, Fort Collins, Colorado, United States (2) Chemistry, Colorado State University, Fort Collins, Colorado, United States (3) Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado, United States

Lipoquinones, such as menaquinones (MK) generally contain fully unsaturated isoprenyl side-chains when present in biological systems found in bacteria; however, partially saturated MK analogs have been reported in literature. The level of unsaturation in the isoprenyl side-chain is likely to affect reactivity and function within the cellular membrane; therefore, a comparison between a fully unsaturated and a fully saturated MK analog would be important for understanding structural differences. Herein, we first carried out a three-step synthesis to yield menaquinone-2 (I,II-H2) abbreviated as MK-2 (I,II-H2). Commercially available 3,7-dimethyl-1-octanol was converted to 1-Iodo-3,7-dimethyloctane via a mesylation reaction and a subsequent substitution reaction to yield the aliphatic iodo product. Then, MK-2 (I,II-H2) was prepared by coupling menadione and 1-Iodo-3,7-dimethyloctane via a radical coupling reaction using benzoyl peroxide as a radical source. We previously characterized the interaction of the fully unsaturated menaquinone-2 (MK-2) with a reverse micelle (RM) model membrane interface where MK-2 was found to interact favorably and penetrate the interface. For structural comparison and the focus of this study, we then investigated the interaction of MK-2 (I,II-H2) with a RM model membrane interface. The characterization of the interaction of this fully saturated MK-2 (I,II-H2) analog versus the previously characterized MK-2 is important for understanding how simple differences in structure can affect the interaction with model membrane interfaces and is important for understanding saturated or unsaturated MK analogs in their native cellular environment.

RMRM 188

Monitoring pH collapse across a bilayer: Modeling the mechanism of action of the anti-tuberculosis drug pyrazinamide

LaRee L. Henry2, Kaitlin Doucette1, Debbie C. Crans2, [email protected]. (1) Colorado State University, Fort Collins, Colorado, United States (2) Biochemistry and Chemistry, Colorado State University, Fort Collins, Colorado, United States

Pyrazinamide (PZA) is an important first-line drug used in the treatment of Mycobacterium tuberculosis (Mtb) infection. Upon diffusing through the mycobacterial cell, PZA is converted to its active form, pyrazinoic acid (POA). The mechanism of action of POA is poorly understood: previous studies, and one of the current accepted mechanisms of action, indicate that the drug works as an ionophore that confers cytoplasmic acidification when the bacteria are exposed to the acidic environment of the phagosome within the alveolar macrophage. In order to observe the mechanism of action by which the drug confers cytoplasmic acidification, a liposomal model is used for studies. A liposomes created in a low concentration phosphorous solution were made such that the intra-vesicular pH is adjusted to 7.4, analogous with the Mtb intracellular pH, and the extra-vesicular pH is adjusted to 5.8, consistent with literature reports of intra-phagosomal pH. The monitor pH collapse across the bilayered membrane, using both fluorescence and 31P NMR spectroscopy such

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that the pH differences between the inside and the outside of the vesicle are observed and any pH collapse induced by POA may be monitored. Our results using this method suggest that there is a change in pH gradient across the bilayer, consistent with the mechanism of action of PZA acting as a ionophore

RMRM 189

Synthesis and in Vitro metabolism of cannibidiol dimethyl ether

Tyler Cale2, [email protected], Richard M. Hyslop1, Shawn Bydalek2. (1) Univ of Northern Colorado, Greeley, Colorado, United States (2) Chemistry and Biochemistry, University of Northern Colorado, Greeley, Colorado, United States

Cannabinoids have been receiving attention in laboratories across the world for their medicinal effects. Cannabidiol (CBD) is one of many active cannabinoids found in marijuana plants, and it has been found to have anti-seizure, neuroprotective, analgesic, and anti-inflammatory effects. There is promise for CBD being a therapeutic agent in the future, and research on the metabolism of different derivatives of CBD could pave the path for the development of new and effective pharmaceuticals. Two procedures for methylation of the phenolic hydroxy groups of Resorcinol (a model compound) and CBD were carried out, effectively changing CBD into Cannabidiol dimethyl ether (CBDD). Products were confirmed with thin layer chromatography, infrared spectroscopy (IR), and H-NMR. As knowledge of the therapeutic effects of CBD grows, it is important to study the metabolism of the derivatives of CBD, such as CBDD, because we may be seeing more derivatives of CBD in the near future.

RMRM 190

UHPLC isolation of tartrate-resistant acid phosphatases from Penicillium spinulosum

Brent A. Schofield3, [email protected], Sandra J. Bonetti1, Jim Carsella2,1. (1) Colorado State Univ Pueblo, Pueblo, Colorado, United States (2) Cell and Molecular Biology, Colorado State University, Pueblo West, Colorado, United States (3) Chemistry, Colorado State University - Pueblo, Pueblo, Colorado, United States

Acid phosphatases (APs) are a subfamily of phosphohydrolases that function ubiquitously in many important processes, including metabolic pathways and cell signal transduction, as well as recycling phosphates to the biosphere. Tartrate-resistant acid phosphatases (TRAPs), the focus of our work, are biomedically significant given their roles in osteoclast function, and prostatic and bone cancers. Because Penicillium species readily produce extracellular phosphohydrolases in liquid-shake cultures, they are ideal organisms for the isolation of TRAPs. Characterization of Penicillium TRAPs could also provide useful information in regard to their protein analogs in pathogenic fungi. Previous explorations into the effects of micronutrient availability on Penicillium phosphohydrolases established that iron(II) supplementation accelerates optimized AP activity. Cultures of P. spinulosum grown in limited-[PO4

3-], tenfold-[Fe2+] modified Raulin Thom (LPmRT) media contained AP activities that were two orders of magnitude greater than in cultures grown in unaltered mRT media. While favorable for amplified enzyme activity, the concentration of ionic salts in the supplemented media interfered with protein separation through both DEAE-Sepharose and CM-

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Sepharose ion exchange (IEX) column chromatographies. Our continuing research employed an instrumental approach to the isolation of TRAPs from P. spinulosum, and began with sample matrix cleanup. Five-day cultures were harvested and filtered, and were immediately subjected to bulk IEX using Chelex 100. Additional filtration through a 0.45 µm filter preceded sample injection onto a size exclusion UHPLC column (SEC). Peak AP activities eluted at 12.6 and 15.8 minutes, at a flow rate of 0.2 mL/min. Characterization of AP proteins in resulting fractions included molecular weight quantitation against standards via SEC, and SDS-PAGE.

RMRM 191

Molecular mechanism of cancer inhibition: Cannibinoids as anti-cancer agents

Joshua A. Folsom3, [email protected], Nicholas A. Pullen4, Corina E. Brown2, Richard M. Hyslop1. (1) Univ of Northern Colorado, Greeley, Colorado, United States (2) Chemitry and Biochemitry, Univ. of Northern CO, Greeley, Colorado, United States (3) Chemistry, University of Northern Colorado, Evans, Colorado, United States (4) Biological Sciences, University of Northern Colorado, Greeley, Colorado, United States

Cannabinoids such as Δ9-tetrahydrocannabinol and cannabidiol have been shown to elicit anti-tumorigenic effects on multiple types of cancer cells in vitro. Several different mechanisms have been proposed such as apoptosis induction, inhibition of angiogenesis and tumor cell migration. The preliminary data show an overall dose-dependent growth inhibition of cancer cells in some lines and an induced proliferative factor at higher doses. The molecular mechanism by which tumor growth is inhibited will be assessed with an initial test on both 4T1 and MCF7 cell lines. Continuing this project with pancreatic, colon, brain, lung and skin, cancer cells Ultimately the goal of this project is to help better understand the anti-tumor effects of cannabinoids and their possible target as therapeutic drug.

RMRM 192

Inflammatory responses of mast cells with cannabidiol and tetrahydrocannabinol

Christopher R. Laster1, [email protected], David Lyons2, Nicholas A. Pullen2, Corina E. Brown1, Richard M. Hyslop1. (1) Chemitry and Biochemitry, Univ. of Northern CO, Greeley, Colorado, United States (2) Biology, University of Northern Colorado, GREELEY, Colorado, United States

This research is being done in order to see if cannabinoids have a significant impact on cells in relation to their tendency towards inflammation. The cells being tested are mast cells both immortalized MC/9 and primary from C57BL/6 and BALB/c mice. Cells from mice are used to simulate possibility of allergic response and asthmatic response, BALB/c being the type that is likely to have allergic and asthmatic responses. Propensity towards inflammation will be determined using ELIZAs of the cytokines present after the cells are incubated with the cannabinoid being tested. Current results show contradictory data compared to some previous research on cannabinoids and certain cytokines, such as IL 6 and 13 which contribute to the reason for and interest in this research. Results are reported as the cytokine quantity per cell.

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RMRM 193

Transparent titanium dioxide nanotubes: Development, characterization, and application in establishing cellular response mechanisms

Jevin Meyerink, [email protected], Grant Crawford. Biomedical Engineering, South Dakota School of Mines & Technology, Rapid City, South Dakota, United States

Titanium dioxide (TiO2) nanotubes have been shown to strongly enhance bone cell behavior and, consequently, have gained attention as potential osteogenetic surface treatments and drug delivery vehicles for titanium-bone implants. The exact mechanism by which TiO2 nanotubes influence cellular function remains controversial, partly due to limitations in existing cellular imaging methods with opaque substrates. Through the fabrication and implementation of transparent TiO2 nanotube imaging platforms, this work aims to establish the mechanistic relationship between nanostructure and bone cell responses to ultimately inform the development of advanced osteogenetic surface treatments for titanium-bone implants. This work identifies electrochemical fabrication conditions for successful production of highly transparent TiO2 nanotube arrays with highly tailorable diameters, as well as their functionality with biological cells. Pre-osteoblast mouse cells (MC3T3-E1) containing fluorescently-tagged focal adhesion protein vinculin and cytoskeletal filament actin were implemented to record real-time, cell-substrate interaction mechanisms via conventional confocal fluorescent microscopy and fluorescent lifetime imaging (FLIM). Similarly, cells containing fluorescence resonance energy transfer (FRET) tension sensors were implemented with these transparent TiO2 nanotube imaging platforms to capture real-time cellular response mechanisms with respect to nanoscale surface properties like nanotube diameter and crystallinity.

Transparent TiO2 nanotube platform (a) used to capture live-cell responses via fluorescently active GFP-Vinculin (b) and mCherry-Actin (c) in pre-osteoblast cells.

RMRM 194

Determining the enzymatic degradation of RNA containing 8-oxo-7,8 dihydroguanine or 8-oxo-7,8-dihydroadenine

Cassandra Herbert1, [email protected], Marino J. Resendiz2. (1) Chemistry, University of Colorado Denver, Denver, Colorado, United States (2) Chemistry, University of Colorado, Denver, Denver, Colorado, United States

The most common oxidative lesion in RNA is 8-oxo-7,8-dihydroguanine (8-oxo-Gua), a product of the reaction between reactive oxygen species and the C8-position in purines. The structure of this lesion is the main cause of variation in function in comparison to the canonical nucleobase in RNA.

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These variations can be explained, in part, through a conformational change that results in a base-pair mismatch (8-oxoGua:Ade). This study relies on the use of ribonucleases to assess local and global changes in RNA structure. Strands of RNA (10-40 nucleotides long) containing 8-oxo-Gua were obtained via solid-phase synthesis and comparatively analyzed with canonical analogs to determine changes in enzymatic degradation. Analysis of enzymatic degradation was accomplished via electrophoretic analyses (PAGE) and chromatography (HPLC). Characterization of the lysates was carried out via mass spectrometry (MALDI-TOF). The commercially available ribonucleases used in this study have different reactivity and specificities: RNase T1 specifically cleaves at the 3’-end of guanosine sites on single-strand RNA and RNase A causes degradation in single stranded RNA with preference toward pyrimidine rings. The structural motifs analyzed include single stands of RNA and RNA/RNA or RNA/DNA duplexes. Duplex formation was established via circular dichroism. RNase T1 prevents degredation at sites containing 8-oxoGua in 1-3 positions indicating 8-oxo-Gua is not a substrate for RNase T1. Enzyme degradation occurs with RNase A due to the conformational change that is expected at 8-oxo-Gua sites and the H-bonding pattern that is equivalent to those expected from pyrimidine containing nucleobases. The degradation patterns established in this study will enable an assessment of the changes in RNA structure due to the oxidative lesion 8-oxo-7,8 dihydroguanine and its possible implications to biologically relevant pathways.

RMRM 195

Cellular toxicity associated with triterpene production in an Escherichia coli heterologous host

Dylan C. Thomas3, [email protected], Parth P. Savani3, David Fox2, Blaine A. Pfeifer4, Rico E. Del Sesto1, Andrew T. Koppisch3, [email protected]. (1) Department of Chemistry, Dixie State University, St. George, Utah, United States (2) Bioscience Division, MS M888, Los Alamos National Laboratory, Los Alamos, New Mexico, United States (3) Department of Chemistry, Northern Arizona University, Flagstaff, Arizona, United States (4) State University of New York at Buffalo, Buffalo, New York, United States

Methylated triterpenes represent an attractive molecular target of the biofuel industry because they are nonoxygenated hydrocarbons that can be processed into transportation fuels using existing industrial hydrocracking infrastructure. The colonial green alga Botryococcus braunii (race B) is a prolific producer of these compounds and reports of 35-70% of the organism’s dry cellular mass is composed of triterpene oils. Despite the promise of these methylated triterpenes as potential advanced biofuels, B. braunii itself has proven to be a challenging organism to culture on a large scale and as a consequence, there is increasing interest in reconstituting triterpene biosynthetic pathways in microbial hosts. Production of terpenoids in prokaryotes is a challenging endeavor. In order to achieve high production titers, delineation of metabolic bottlenecks and identification of how and where production-associated toxicity manifests are necessary. In this work, we describe our current efforts to reconstitute methylated triterpene biosynthesis in E. coli, with a focus on the model triterpene, squalene. The heterologous host was engineered with plasmids encoding squalene synthase lacking a C-terminal membrane associated domain (pHY-SQS-tr, kanr) and one encoding genes for farnesyl diphosphate synthesis through the mevalonate pathway (pMBIS, tetr). While squalene production by the resultant strain was verified (via 1H NMR and GC-MS) upon exogenous supplementation of metabolites that enter upstream biosynthetic pathways to isoprenoid diphosphate precursors (isopentenyl diphosphate and dimethylallyl diphosphate), cellular toxicity increased as a function of supplement concentration. Furthermore, our engineered strain exhibited

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very poor growth both in the absence of supplementation, and in conditions where the supplement is in excess. Our results demonstrate that triterpene producing E. coli heterologous hosts are subject to cellular toxicity that may arise from at least three distinct metabolic mechanisms.

RMRM 196

Investigating the mycofactocin biosynthetic pathway

Richard S. Ayikpoe, [email protected]. Chemistry and Biochemistry, University of Denver, Denver, Colorado, United States

The onset of multidrug resistance of Mycobacterium tuberculosis (Mtb) has necessitated the need to discover new treatment strategies to combat tuberculosis. The mycofactocin biosynthetic pathway is a required pathway for Mtb growth on cholesterol, a major carbon source for the organism during latency. Mycofactocin biosynthesis is carried out by at least four enzymes: MftC, MftD, MftE and MftF. MftC catalyzes the decarboxylation of the C-terminal tyrosine and subsequently forms a C-C bond between Val29 and Tyr30 of the precursor peptide MftA. MftC contains at least two [4Fe-4S] clusters: an indispensable radical-SAM [4Fe-4S] cluster and at least one auxiliary cluster. The additional auxiliary [4Fe-4S] cluster(s) are important for enzymatic activity, though their exact roles are unknown. MftE is a creatininase homolog that catalyzes the peptide cleavage of the last two residues of modified MftA. It remains to be determined if MftE cleaves the trans modified MftA intermediate or crosslinked valine-tyrosine product. MftD is an FMN-binding dehydrogenase that catalyzes the modification of the product of MftE cleavage. However, the mechanism and the product of this modification is yet to be determined. Herein, we investigate the enzymes involved in the modification of this novel pathway and to help determine the structure and the physiological importance of the product of the mycofactocin pathway.

RMRM 197

Formation of protein coronas on metallic nanoparticles and removal of metallic cores

Erast Davidjuk, [email protected], Scott M. Reed, Desmond Hamilton. Chemistry, University of Colorado Denver, Lone Tree, Colorado, United States

The binding of proteins to metal nanoparticles results in a protein corona surrounding the core of the nanoparticle. The resultant materials are toxic, although it is unknown whether it is the metallic nanoparticles themselves or the mis-folding of proteins within the corona that produces this toxicity. We seek to investigate the relative toxicity of uncoated metallic nanoparticles, metallic nanoparticles encapsulated in a protein corona, and the protein corona absent the metallic core. Silver nanoparticles were synthesized using tannic acid and trisodium citrate and gold nanoparticles were synthesized via reduction of chloroauric acid with trisodium citrate. Nanoparticles were encapsulated in C-reactive protein (CRP) as a model serum protein. Localized surface plasmon resonance measurements were used to optimize the amount of CRP needed to form the protein corona and to determine the amount of cross-linking agent required to covalently link CRP into a continuous shell. A technique was developed for removing the metallic core using a cyanide etch and the resulting corona was purified with dialysis prior to toxicology studies. The characterization of the nanoparticles and their protein corona with dynamic light scattering and ultraviolet-visible spectroscopy will be presented.

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RMRM 198

Investigating the antidiabetic effects of metformin on pyruvate carboxylase

Guadalupe Solis, [email protected], Shawn Bydalek, Corina E. Brown, Richard M. Hyslop. Chemistry and Biochemistry, University of Northern Colorado, Greeley, Colorado, United States

Metformin is most commonly prescribed for the treatment of type II diabetes, a disease in which the effects of insulin are desensitized leading to hyperglycemia. While the clinical effects of metformin are clearly established, the exact targets of metformin action remain unclear. Due to the relative low cost of metformin, it is widely accessible to communities around the world. Currently at 150 million per year, the number of users dependent on metformin for quality of life continues to increase. Thorough investigation of the drug and all possible targets involved in antidiabetic action becomes crucial. Thus, the purpose of this study was to further elucidate the mechanism of action for metformin, helping to further understand the adverse effects of the drug. The present study assessed the hypothesis that metformin elicits antidiabetic effects through inhibition of pyruvate carboxylase (PC), an anapleurotic enzyme involved in mitochondrial gluconeogenesis. The hypothesis was addressed through spectrophotometric analysis of the specific activity of purified bovine PC treated with metformin above and near pharmacokinetically consistent concentrations (250-2,500 µM; n=8). 13C-NMR analysis of interaction between metformin and biotin, the prosthetic group of PC, was also performed. One-way ANOVA demonstrated a significant difference between treated and control groups, F(4, 10) = 5.06, p = .0172 for the assays. Duncan-Waller post-hoc analysis demonstrated significant differences between 500-2,500µM and control. Results of this study help further explain conditions such as lactic acidosis, a common adverse effect of metformin described as painful and imparting pain of the extremities.

RMRM 199

Analysis of organic and inorganic compound in tattoo ink

Connor Hansen3,2, [email protected], Richard M. Hyslop1, Corina E. Brown2. (1) Univ of Northern Colorado, Greeley, Colorado, United States (2) Chemitry and Biochemitry, Univ. of Northern CO, Greeley, Colorado, United States (3) Biology, University of Northern Colorado, Denver, Colorado, United States

For millennia humans have been tattooing themselves as a form of cultural expression as well as a fashion statement for many; however it is common that the recipients of these tattoos do not consider what might be injected under their skin. Many inks use a combination of organic pigments and different heavy metals to comprise the colorful dye of the tattoo ink. In this study, 14 different colors of ink were analyzed for their heavy metal content using X-ray fluorescence, as well as their organic components using gas chromatography coupled with mass spectrometry. The different colors consisted of black, white, blue, red, green, yellow, pink, and purple, including some variations of these shades (lavender, magenta, baby blue, lime green, dark red and violet). Many of the metals that can be found in these dyes are skin irritants, and some are toxic. Some noteworthy metals found in these specific dyes are: Cu, Ba, Fe, V, Ti, As, Pb, Ni, Sr, and Se, although these does not encompass every metal found. Many dyes also contained pigments that are more commonly used in the production of printer and pen inks/toners.

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RMRM 200

Brewing flavor chemistry: Analytical challenges and opportunities

Dana L. Sedin, [email protected]. New Belgium Brewing Company, Loveland, Colorado, United States

Beer is a complex matrix composed of hundreds of organic compounds that can impact the taste, aroma, color, and body. Many of these compounds are flavor active at part-per-billion to part-per trillion concentrations. These compounds can come from the raw materials, be formed during the brewing process, can come from unintentional yeast or microbial contamination, or be formed while beer is aging. Even though these compounds can be detected through sensory perception, many are difficult to detect and quantify analytically. This presentation will provide an overview of flavor development in beer along with current analytical techniques used to measure these compounds. Specific examples of flavor projects we are conducting (both positive and negative flavors) will be discussed.

RMRM 201

Mousey off flavor in beer: Origins and control

Lindsay Barr, [email protected]. New Belgium Brewing, Fort Collins, United States Minor Outlying Islands

The ‘mousey’ off flavor is well known in the wine and cider industry but is seldom discussed when it comes to beer, in spite of the large recognition of it being a problem in sour beer production. An expert sensory panel was utilized to recognize the off flavor in a variety of sour beers, compounds responsible for the ‘mousey’ flavor were identified by GC-MS/O, production parameters and a variety of specific organisms were explored as culprits, with the purpose of better understanding how breweries can control the onset and rise of this flavor. Other factors, like individual panelist sensitivity, were measured to gain understanding on the influence of individual’s physiology as it pertains to the flavor’s recognition and quantification. Sensory, analytical and microbiological measurements were correlated to gain a better understanding of the flavor’s origins and control.

RMRM 202

Art & mystery of malting: A simple man's view

Mont Stuart, [email protected]. MillerCoors, Golden, Colorado, United States

Malted barley has been used for over 8,000 years to brew beer. While the malting equipment may have changed over this time, the basic process remains largely unchanged. Good quality barley is soaked in water during the steeping process, it is then germinated under controlled temperature and moisture before growth is arrested by the kilning process. The major aims of malting are to produce colour, flavour and most importantly, enzymes that can break down the myriad of molecules within the barley grain, including complex cell wall carbohydrates, proteins and starches. During germination, these enzymes firstly degrade the cell wall carbohydrates and partially

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breakdown proteins to liberate starches that are subsequently converted into simple fermentable sugars during mashing in the brewhouse. These sugars are converted into alcohol during fermentation and the resultant beer is matured, filtered, carbonated and packaged for consumption by beer lovers all over the world. This paper will review the origins of malting and brewing before evaluating how barley quality is influenced by growing and storage conditions. It will also describe the malting process and how it can be adjusted to optimize the resultant malt quality in order to meet the strict standards of the brewer.

RMRM 203

DMS formation by lager yeast strains – A possible role for mitochondria

Eric Samp, [email protected]. Craft Supply Chain, MillerCoors, Golden, Colorado, United States

Dimethyl sulfide (DMS) imparts a black olive, cream corn like flavour volatile to American and European lagers and thus brewers strive to control its level in their products. In order to control DMS in beer, brewers focus on establishing specifications on malted barley S-Methyl Methionine (SMM) levels which is a precursor of DMS. In addition to this precursor level, brewers pay careful attention to wort processing requirements, namely boil time and the total time for hot wort clarification in the whirlpool as further degradation of SMM leads to DMS formation. However, this is not the sole control mechanism for DMS. In a series of wort stripping experiments where flavour volatiles were removed via vacuum stripping, it was noted moderate levels of DMS were produced during fermentation. Previous research by Bamforth and co-workers suggested another pre-cursor, Dimethyl sulfoxide (DMSO), could be reduced to DMS via a DMSO reductase like enzyme. In a 23 factorial design supplementing wort with methionine, methionine sulphoxide (MetSO), and DMSO, it was confirmed that DMS is formed from DMSO with the lager strain studied. Furthermore, the results of MetSO supplementation demonstrated that complete inhibition of the formation of DMS suggesting a MetSO Reductase enzyme system is involved. In the process of altering the wort carbohydrate spectrum from being predominantly maltose to one much richer in glucose through adjunct changes, a significant reduction in beer DMS level was noted even though the malt SMM level remained consistent during this time frame. Since it is known that glucose inhibits the development of both mitochondria and its unique lipid, cardiolipin, we speculated that this organelle was involved. In a series of replicated incubation experiments aimed at altering cardiolipin content in yeast, it was found that beer DMS levels at the end of fermentation were moderately higher (about 10 µg/l) under incubation conditions that promote cardiolipin formation, namely incubation in glycerol and L-thyroxine. Comparatively, conditions that would limit cardiolipin formation (control and inositol incubation) resulted in lower DMS levels (p-val < 0.05). It is speculated that decreased MetSO reductase activity inside the mitochondrion is somehow reduced.

RMRM 204

Application of metabolomics to understand the chemistry of flavor and flavor stability in beer

Adam Heuberger1, [email protected], Harmonie Bettenhausen1, Lindsay Barr2, Corey Broeckling1, Christian Holbrook2, Jessica Prenni1, Dana L. Sedin2. (1) Colorado State

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University, Fort Collins, Colorado, United States (2) New Belgium Brewing Company, Loveland, Colorado, United States

Metabolomics is a high-throughput biochemical profiling method that provides a comprehensive overview of metabolism in biological systems. Recent studies have used metabolomics to investigate aspects of food science. Here, the method and application of mass spectrometry (MS) metabolomics to understand flavor and flavor stability will be reviewed, and includes a case study in beer production and sensory quality. MS-metabolomics was used to measure chemical variation in small molecules of barley, malt, and beer, and the data was integrated with metrics for barley quality, beer flavor and flavor stability. Experiments were performed on UHPLC-MS (reverse phase and HILIC), GC-MS, and HS/GC-MS platforms with custom data processing workflows. The data demonstrated significant metabolite variation in barley associated with variety, growing location, and genotype by location interactions. Independent metabolomics experiments on beer reveal information about purine metabolites associated with aging and flavor stability. Taken together, these data provide new information about the extent of chemical variation in barley and the association to malting quality, beer flavor and flavor stability. Concepts that will be discussed include: how to perform MS-metabolomics and integrate the data with sensory analysis, characterizing metabolite variation during beer aging, and understanding the influence of raw materials and genetics on beer flavor chemistry.

RMRM 205

Observing humulone isomerization by polarimetry

Sean E. Johnson2, [email protected], Michael D. Mosher1, [email protected]. (1) Dept Chemistry Biochemistry, University of Northern Colorado, Greeley, Colorado, United States (2) Department of Chemistry and Biochemistry, University of Northern Colorado, Greeley, Colorado, United States

Humulone, also known as the α-acid in hops, is isomerized during wort boiling to produce a mixture of iso-humulones, the iso-α-acids which provide the bittering flavors in finished beer. The reaction, a base-promoted acyloin condensation, follows first-order kinetics. This process is typically studied by taking aliquots of the wort during the boiling process and analyzing them by HPLC. The use of polarimetry allows rapid evaluation of a wide variety of individual effects on the overall reaction. The overall isomerization rate and pKa of humulone can be quickly determined. In addition, because the reaction can be studied outside of the complexity of wort as a solution matrix, the dependence of the isomerization on pH, temperature, solvent, and divalent cation identity is easily observed.

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RMRM 206

CO2 analysis in decarboxylation reactions throughout fermentation

Ashley Campanella, [email protected]. Chemistry and Biochemistry , University of Northern Colorado , Greeley, Colorado, United States

The use of multi-bounce ATR-IR to measure aqueous CO2 concentrations allows the rapid and real-time analysis of decarboxylation reactions. We have studied the thermal decomposition of ethyl acetoacetate under a variety of conditions by varying pH, temperature, and other parameters. This evaluation has also been applied to the evaluation of yeast-driven fermentation during the beer making process. In addition to providing information about the rate of fermentation (production of carbon dioxide via metabolism), we have used this process to study the extracellular oxidative decarboxylation of α-acetolactate produced in the rapid growth phase of yeast during fermentation. The rate of CO2 production during fermentation has been evaluated based on pH, temperature, and other parameters. Herein our report results of the use of multi-bounce ATR-IR spectroscopy as a tool for measuring these decarboxylation reactions.

RMRM 207

Development of dendrimeric metallacrowns

Vincent L. Pecoraro1, [email protected], Beatriz Lopez-Bermudez1, Svetlana Eliseeva2, Stephane Petoud2. (1) University of Michigan, Ann Arbor, Michigan, United States (2) Centre de Biophysique Moléculaire, cnrs, Orléans, France

Metallacrowns (MC) have been shown to have superior luminescent properties, particularly for Near Infrared (NIR) emitting ions such as Yb(III) and Nd(III). Previously, we reported that LnGa4(benzoate)4 metallacrowns are capable of sensitizing eight different Ln ions. More recently, we converted this monomeric MC into a Ln2Ga8(isophthalate)4 dimer that may be readily functionalized. In this presentation, we will discuss the synthesis of striped PAMAM dendrimers of Ln2Ga8(isophthalate)4 that are linked off of the isophthalate using an appended maleimido functional group. We will also discuss the photophysical properties of these new nanomaterials.

RMRM 208

Cytotoxic titanium(IV) compounds prepared with iron chelators attenuate the bioavailability of the intracellular labile iron pool

Arthur D. Tinoco1, [email protected], Sergio A. Loza-Rosas1, Alexandra M. Vazquez1, Kavita Gaur1, Sofia C. Perez1, Elisa Tomat2, Eman A. Akam2, Andrei V. Astashkin2, Manoj Saxena3, Shweta Sharma3, Nicholas Noinaj4, Yamixa Delgado1, Kennett I. Rivero1, Lenny Negron1, Timothy B. Parks5, Josue Benjamin1, Yahaira M. Cruz1, Angel L. Vazquez1. (1) Chemistry, University of Puerto Rico Rio Piedras, San Juan, Puerto Rico, United States (2) Chemistry, University of Arizona, Tucson, Arizona, United States (3) Environmental Sciences, University of Puerto Rico Rio Piedras, San Juan, Puerto Rico, United States (4) Biological Sciences, Purdue

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University, West Lafayette, Indiana, United States (5) VA Caribbean Healthcare System, San Juan, Puerto Rico, United States

Combining the potential of titanium(IV) to inhibit cellular use of iron(III) with Fe(III) chelators affords a synergistic strategy to dramatically decrease iron bioavailability in cancer cells. Our recent x-ray crystal structure of Ti(IV) bound to the blood protein serum transferrin (sTf), the dominant cellular Fe(III) transporter, reveals fundamental Fe(III) and Ti(IV) coordination differences that elucidate ligand moieties to favor Fe(III) binding. In this work, the Fe(III) affinity preference of iron chelators that mimic sTf coordination of Fe(III), termed chemical transferrin mimetic (cTfm) ligands, is exploited to create anticancer Ti(IV) complexes. These complexes are designed to become activated in the intracellular environment by the process of Fe(III) induced transmetalation, releasing Ti(IV) to reach intracellular targets while chelating Fe(III) with such high stability to render it functionally inaccessible. Two parent cTfm ligands are selected for this study: deferasirox, a FDA-approved drug to treat iron overload disease, and N,N'-di(o-hydroxybenzyl)ethylenediamine-N,N'-diacetic acid (HBED). A suite of analytical tools including UV-Vis spectroscopy, 1H NMR, mass spectrometry, and potentiometry show mononuclear species to be the physiologically relevant aqueous speciation of the Ti(IV) cTfm complexes at micromolar concentrations of metal and ligands, indefinitely stable in the broad pH range of 4 to 8. Transmetalation of these complexes are tested with Fe(III)-bound sTf and Fe(III) citrate, a labile Fe(III) source. The metal exchange is triggered exclusively by the labile Fe(III) source and takes place soon after solution mixing suggesting excellent feasibility of this process. The correlation of the cytotoxicity of the Ti(IV) cTfm complexes with decreasing Fe bioavailability was examined by supplementing cells with Fe(III) and by studying changes in the high spin Fe(III) intracellular population via whole-cell EPR studies. The changes were also assessed by monitoring the inactivation of the Fe(III)-containing enzyme ribonucleotide reductase (RR), responsible for DNA synthesis, via the disappearance of its EPR active tyrosyl radical.

RMRM 209

Pyrazinoic acid: Using mechanistic modelling to unravel the origin of pyrazinamide's synergy with other tuberculosis drugs

Dean C. Crick2, [email protected], Fabio Levi Fontes3, Steven Rooker2, Benjamin Peters1, Debbie C. Crans3, Michael A. Lyons2. (1) Chemistry, Colorado State University, Fort Collins, Colorado, United States (2) Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado, United States (3) Colorado State University, Fort Collins, Colorado, United States

PZA is unique among current TB drugs in that it demonstrates impressive sterilizing activity and synergy with other TB drugs, but its activity is not potent and pH dependent in vitro, and the mechanism of action against M. tuberculosis remains controversial. Proposed mechanisms of action of pyrazinoic acid (POA), the active form of PZA, include inhibition of many enzymatic targets and acidification of the bacterial cytoplasm. Here, the impact of POA and structural analogs on ΔΨ and ΔpH, the two components of proton motive force (PMF), and bacterial growth was determined in M. tuberculosis H37Ra. The results show POA and analogs act similarly to uncouplers, collapsing mycobacterial PMF at extracellular pH values between 6.0 and 8.0. This effect correlates with the concentration of compound required to inhibit 50% of growth in culture (GIC), implying uncoupling is a primary cause of growth arrest.

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A QSAR model, built on the Hill equation and acid base physical chemical properties, was developed to understand the relationship between the GIC and the in vitro pH dependence of POA and analog activity. The model shows a strong correlation between GIC, the extracellular pH and the pKa of the uncoupler tested and indicates that the uncoupling activity requires compounds with pKa values between 3.0 and 5.5, as the uncoupling activity is correlated to the presence of the protonated form of the compounds. Analogs with more acidic pKa values are charged (fully deprotonated) at the pH range where mycobacterial cells are able to grow and, thus, inactive and TB drugs that have that have no in vitro pH dependence and known mechanisms of action (such as isoniazid) do not fit the model. To determine if synergism with other anti-tuberculosis drugs is correlated with uncoupling activity, checkerboard assays were performed at external pH values corresponding to those used to determine GIC and PMF collapse. While this work is still in progress, POA and the analog salicylic acid, a known uncoupler, potentiate the effect of tuberculosis drugs, in a manner directly correlated with uncoupling activity. Thus, the data provides a predictive model for PZA/POA activity in vitro and a hypothesis for the mechanism behind synergy in the current standard treatment for M. tuberculosis infection. Overall, the model potentially provides a framework to assist in the synthesis of novel compounds able to synergize with existing antibiotics.

RMRM 210

Relationships between plasma metal ions and the development of infectious diseases in health and disease

Peggy L. Carver, [email protected]. Clinical Pharmacy, University of Michigan College of Pharmacy, Ann Arbor, Michigan, United States

Divalent metals are important components of nutrition, are required for cellular growth and metabolism, and may play a role patients' susceptibility to infection. [1,2] Subtle alterations of divalent metal homeostasis occur in the course of infectious diseases, to reduce the availability of respective metals to microbes, or to use toxic metal accumulation to eliminate pathogens. While there are no known correlations between with Cu levels and the development of infectious diseases, in Zn-deficient patients, supplementation has shown substantial health benefits in in select high risk populations. An increased plasma Cu/Zn ratio has been demonstrated in select immune compromised patient populations. [2,3] Methods: We assessed correlations between metal ion concentrations and bacterial and fungal infections in (1) acutely ill hospitalized patients, and (2) in stable, otherwise healthy patients receiving long-term parenteral nutrition (TPN). Data collection included all fungal and bacterial infections, doses and plasma levels of metal ions, and documented infections. Multivariate analyses, recurrent events survival analysis, and a Glimmix procedure to analyze correlation between plasma levels of the metal ions and infections. Results: In stable, healthy TPN patients, there was a significant dose-response relationship between weekly metal ion doses and serum concentrations for Zn, Cr, and Mn, but not for Se, Cu, or Fe. An increased risk of infections was associated with increased plasma Cu/Zn ratios (P<0.002). Higher cumulative doses of Fe were a risk for for infections by gram negatives and fungi. In acutely ill hospitalized patients, an increased risk of infection correlated with red blood cell transfusions, high iron saturation, and renal failure, and the Cu/Zn ratio was significantly different in

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infected vs uninfected patients. Conclusions: Further characterizing correlations between plasma Cu/Zn ratios and the development of infections may help minimize the risk of infections in both healthy and hospitalized patients. Future studies need to interrelationships between metal ion concentrations. They should be prospective, and incorporate assessments of multiple metal ions, over time, in patients at risk of infection.

RMRM 211

Investigations into the ideal coordination geometries of vanadium-based enzyme inhibitors

Craig C. McLauchlan2, [email protected], Craig A. Wallace2, Michael Tarlton2, Debbie C. Crans1. (1) Colorado State University, Fort Collins, Colorado, United States (2) Dept of Chemistry, Illinois State Univ, Normal, Illinois, United States

Vanadate and vanadium compounds are known inhibitors for phosphorylases and phosphatases. A range of vanadium complexes have been shown to inhibit phosphatases, including a number of different ligands, some which have been found to remain on the vanadium as the enzymes are inhibited. Five-coordinate geometries for transition metal ions such as vanadium, however, are often found to be between the idealized square planar and trigonal bipyramidal geometries, the latter being more in line with the five-coordinate exploded transition-state geometry of phosphate ester hydrolysis. However, other coordination geometries and other metal complexes have been characterized as inhibitors, suggesting that the structural features are not the sole reason for the observed potency in the complexes. Here we present an analysis of the structural parameters from X-ray crystallography of five-coordinate vanadium complexes with a VO4X core geometry (X = C, N, O, Cl, F, S) and comparing this to the vanadium-based inhibitors crystalized inside various phosphorylases. We will compare each structure to the ideal transition state geometry for phosphate ester hydrolysis, to evaluate the importance of the small structural perturbation in small molecule structures and inside a protein and possible uses of peptides for additional stability/interaction. These considerations demonstrate that a trigonal bipyramidal geometry is observed in the vanadium-phosphatase complexes even though the square pyramidal geometry is more stable for the complexes themselves outside the protein. These observations were compared to the biochemical data available measuring Ki values for oxovanadates as well as other oxometalates and finally for vanadium compounds. Together these data provide direction with regard to inhibitor design and the consequences of speciation. Here we present our latest results including similar analysis with the haloperoxidase systems.

RMRM 212

Vanadium compounds as synergetic agents in oncolytic virotherapy

Debbie C. Crans1,4, [email protected], Mohammad Selman2,3, Jean-Simon Diallo2,5. (1) Colorado State University, Fort Collins, Colorado, United States (2) Centre for Innovative Cancer Research, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada (3) 3 Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, Ontario, Canada (4)

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Cell and Molecular Biology, Colorado State U, Fort Collins, Colorado, United States (5) Department of Biology, University of Ottawa, Ottawa, Ontario, Canada

Oncolytic viruses are an emerging class of anticancer bio-therapeutics that induce antitumor immunity through selective replication in tumor cells. We introduce a strategy that boost the therapeutic efficacy of oncolytic viruses by combining their activity with immuno-modulating small molecules protein tyrosine phosphatase inhibitors. The inhibitory properties of vanadium are attributed to the favorable five-coordinate geometry of phosphate ester hydrolysis transition states. Five coordinate geometries for transition metal ions such as vanadium, however, are often found to be in an intermediate form between square planar geometry and trigonal bipyramidal geometry. A number of compounds have been used as inhibitors, and detailed interaction of vanadate with phosphatases have described crystallographically. We found that vanadium-based phosphatase inhibitors could enhance oncolytic viruses infection in vitro and ex vivo, in a number of resistant tumor cell lines. Furthermore, vanadium compounds increased anti-tumor efficacy in combination with oncolytic viruses in several syngeneic tumor models, leading to systemic and durable responses, even in models otherwise refractory to oncolytic viruses and drug alone. Overall, we present studies on a new ability of vanadium-based compounds to simultaneously maximize viral oncolysis and systemic anticancer immunity, offering new avenues for the development of improved immunotherapy strategies.

RMRM 213

Synthesis and characterization of lithium doped magnesium oxide (111) catalysts for the oxidative coupling of methane

Allyson M. York1, [email protected], Dakota Isaak2, Ryan M. Richards2, Brian G. Trewyn3. (1) Chemistry, Colorado School of Mines, Golden, Colorado, United States (2) Chemistry and Geochemistry, Colorado School of Mines, Golden, Colorado, United States (3) Dept Chem Geochem, 152 Coolbaugh Hall, Colorado School of Mines, Golden, Colorado, United States

Lithium magnesium oxide (Li/MgO) catalysts have been widely used to perform the oxidative coupling of methane reaction (OCM) for over three decades since their utility was discovered in 1985. The OCM reaction involves activating the C-H bond in methane to create methyl radicals, and subsequently coupling these radicals to form ethane or ethylene (via dehydrogenation). Efforts to activate methane are substantial, as the C-H bond is quite strong. However, converting methane into ethane or ethylene is energetically favorable as both C2 products are more energy dense than methane. In addition, ethylene production is one of the most important reactions within the petrochemical industry; about 330 billion pounds are used per year, which brings the market to over $200 billion annually. This makes the OCM of methane from oil sequestration attractive; if methane can be converted into ethylene, it can contribute largely to the growing need for this key chemical precursor. While Li/MgO catalysts work well for the OCM reaction, the mechanism through which these catalysts activate methane and couple methyl radicals together is still unknown, albeit not without valiant efforts by many around the world to elucidate this daunting question. Current literature suggests that lithium precursors act as a structural modifier and create corner, step, and edge sites on magnesium oxide crystals when reacted post-synthetically via wet impregnation methods. Lithium ions have been found to induce (111) and (110) facets of magnesium oxide crystals in catalysts that were particularly active for the OCM reaction. This background led to the hypothesis that lithium magnesium oxide nanosheets possessing solely the (111) facet could be excellent catalysts for the OCM reaction. Systematic synthesis of various weight percentages of

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Li/MgO (111) via new post-synthetic methods and co-synthetic methods has been pursued. This presentation aims to provide updates on the characterization (physisorption, chemisorption, DRIFTS, XRD, and others) of these novel materials to illuminate the mechanism through which OCM occurs over Li/MgO catalysts.

RMRM 214

Development of a novel selective synthesis of solid ionically conductive materials through electrochemical corrosion

Jacob D. Schneider1, [email protected], Jeffrey Ma1, Amy L. Prieto2, James R. Neilson1. (1) Chemistry, Colorado State University, Fort Collins, Colorado, United States (2) Chemistry Department C210, Colorado State University, Fort Collins, Colorado, United States

In order to develop the next generation of solid-state energy storage devices, major improvements need to be made in fast ion conducting solid materials. Current solid inorganic fast ion conductors all have shortcomings, and improvement of these materials has been incremental. The best materials rely on defects or disorder, which makes theoretical investigations non-trivial. We are aiming to accelerate the discovery of new materials by developing a synthetic paradigm wherein the synthetic method selectively forms materials with ionic conduction. We employ electrochemical corrosion to produce films of an ionic conductor directly on an electrode, however, if the reaction forms unfavorable, ionically insulating products, the reaction will cease. These processes are depicted in Figure 1. To explain the concept I will first present successful proof of concept experiments using AgI. The corrosion of Ag electrodes in the I-containing electrolytes results in a variety of products (Figure 2). These products were characterized using electron microscopy, X-ray diffraction, and impedance spectroscopy. Preliminary work on Cu2-xSe and MxPSy (M = Cu, Li, Na) will also be presented. The short term outlook is to develop techniques and systems that can synthesize known compounds. This practical and scalable synthetic method yields a full half-cell, with a solid electrode and electrolyte, as the product. Our method allows for faster screening, and materials with multiple desired properties. In addition to fast-ionic conduction, the activation energy for the transport of the mobile ion across the electrode/ electrolyte interface must be sufficiently low, which is often an issue. Lastly, as the synthesis targets desired properties rather than specific compounds, we are more likely to find systems difficult to predict by current theoretical methods such as non-thermodynamic phases, amorphous, or highly defected materials.

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RMRM 215

Development of a nanocrystal synthesis of copper phosphorus selenide (Cu3PSe4): Investigation into an overlooked material for PV applications

Jennifer Lee1, [email protected], Amy L. Prieto2. (1) Chemistry, Colorado State Univeristy, Fort Collins, Colorado, United States (2) Chemistry Department C210, Colorado State University, Fort Collins, Colorado, United States

Ternary and quaternary copper-based chalcogenide semiconductor nanocrystals have emerged as promising materials for photovoltaic absorbers because they are composed of low toxicity, earth-abundant elements and offer wide tunability via control over the composition of their constituent elements. One material that is not well-studied for photovoltaics yet is the p-type semiconductor copper phosphorus selenide (Cu3PSe4). It has a direct bandgap of 1.40 eV, ideal for absorbing the solar spectrum. In order to enable Cu3PSe4 as a viable material for commercial use, a colloidal nanocrystal synthesis, which takes advantage of low-cost and facile fabrication, must be developed. However, what is currently known and understood about Cu3PSe4 is limited to DFT calculations and characterizations following bulk solid-state syntheses. There are significant synthetic challenges in controlling phase and composition in the preparation of high quality ternary and quaternary nanoparticles in general. In this case, circumventing the preferential formation of thermodynamically

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stable Cu-Se binaries. The incorporation of phosphorus also poses a significant challenge as it is a low molecular weight main group element that has poorer orbital overlap with heavier chalcogens such as Se. In order to rationally develop a colloidal nanocrystal synthesis of this material, a robust understanding of the different precursors as well as their behavior and reactivity in different solvents are required to understand how the desired element is delivered. Because there is no proposed mechanism on how Cu3PSe4 might form, preparations were initially guided by common chalcogenide precursors reported in literature such as selenium powder in oleylamine (OLA) or diphenyl diselenide. It was later recognized more nuanced considerations were required as the use of these reagents typically result in the formation of binary phase impurities. Therefore, a careful balance of precursor concentration, stability, and chemical potential coupled with reaction temperature and solvent considerations will be presented in order to ultimately tailor material properties toward the desired photovoltaic application

RMRM 216

Mechanistic studies into Cr-catalyzed photoredox reactions

Robert Higgins, [email protected]. Colorado State University, Fort Collins, Colorado, United States

Within the field of photoredox catalysis, there is an opportunity to perform novel reactions without the use of expensive or caustic reagents. Typically, ruthenium and iridium complexes have been employed as photosensitizers; however, recent reports have shown that chromium complexes are also suitable catalysts for this type of reactivity. For example, formal [4+2] cycloadditions have been shown to proceed in the presence of both [Cr(Ph2phen)3]3+ (Ph2phen = 4,7-diphenylphenanthroline) and [Ru(bpz)3]2+ (bpz = 2,2’-bipyrazine), but important mechanistic differences have been noted dependent on photosensitizer choice. From a thorough investigation of the mechanism(s) for these processes, we have determined that there is a association event between the substrates and [Cr(Ph2phen)3]3+. We have further investigated this phenomenon with a model complex [(phenda)2CrCl2]+ (phenda = 1,2-diaminobenzene) in order to asses thermodynamic parameters related to this association event. In all, this mechanistic investigation offers insights into the origin of the orthogonal reaction pathways observed between Cr and Ru-congeners, offering an alternative approach for this field.

RMRM 217

Synthetic surface studies of iron sulfide nanocrystals

Rebecca C. Miller1, [email protected], Amy L. Prieto2. (1) Chemistry, Colorado State University, Fort Collins, Colorado, United States (2) Chemistry Department C210, Colorado State University, Fort Collins, Colorado, United States

Iron pyrite has long been examined as a potential photovoltaic absorber layer give its promising optical properties and the low cost and earth abundance of its constituent elements.1 Efforts to produce efficient solar cells have been limited by the low open circuit voltages attained.2 Both bulk defects, likely sulfur vacancies, and a surface inversion layer in nominally n-type iron pyrite are suggested to contribute to the low photovoltages and efficiencies observed.3,4 Avoiding these

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defects may possibly be achieved through low temperature synthetic routes, such as solution-phase nanocrystal syntheses. Additionally, increasing the thermal stability of FeS2 via alloying with other elements or forming related compounds such as Fe2GeS4 are called upon for improving pyrite’s performance.5,6 However, should bulk defects of pyrite be minimized, surface defect states must still be addressed, especially due to the high surface area of nanocrystalline materials. A common route to passivating nanocrystal surfaces involves forming a core/shell morphology with a protective, thin layer of an isostructural material, and our work aims at developing a core/shell nanocrystal synthesis for FeS2 as the core. Preliminary results show incorporation of the desired shell material into the core, forming solid solution Fe1–xMxS2 nanocrystals, which may enhance thermal stability and tune other properties. These nanocrystal syntheses provide the scaffolding for further surface passivating processes of optimizing post-synthetic ligand exchange procedures. Altering these iron sulfide nanocrystals compositionally, morphologically, and through surface exchange may allow us to improve upon the observed low photovoltaic performance.

RMRM 218

Impurity phase effects on the electrochemical performance of electrodeposited SnSb

Jeffrey Ma2, [email protected], Amy L. Prieto1. (1) Chemistry Department C210, Colorado State University, Fort Collins, Colorado, United States (2) Chemistry, Colorado State University, Fort Collins, Colorado, United States

Currently, graphite is the primary choice for lithium anode materials that commercial industries use. However, graphite has a low theoretical gravimetric capacity (~372 mAh/g vs Li), which research and industry has already been able to fully utilize. In order for next generation applications, such as all-electric vehicles, to be more viable, materials with higher gravimetric and volumetric capacities are desirable. Intermetallic alloys, such as SnSb, with their higher energy densities are a candidate to replace graphite. Electrodeposition is a promising method of synthesis for these alloy materials, as it can control the composition, the particle size, and the thickness of the material. In this study, electrodepositions of SnSb were performed, where purity, particle size, and thickness of the material were tuned based on multiple conditions. Electrochemical testing of SnSb in lithium- and sodium- ion batteries suggests promising performance and cycle life of the material. Non-pure SnSb phase samples were also synthesized to show the importance of purity of the synthesized electrodes, and how purity of the material can affect the cyclability of the anode material.

RMRM 219

Voltage dependent solid electrolyte interface formation on copper antimonide anodes for lithium-ion batteries

Leslie A. Kraynak1, [email protected], Amy L. Prieto2. (1) Chemistry, Colorado State University, Fort Collins, Colorado, United States (2) Chemistry Department C210, Colorado State University, Fort Collins, Colorado, United States

The carbonate-based electrolytes used in lithium-ion batteries are not stable over the potential regions where lithium-ion batteries operate, resulting in the formation of a passivating layer called the solid electrolyte interface (SEI). The SEI plays a crucial role in the performance of lithium-ion

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batteries, affecting the irreversible capacity loss, self discharge, rate capability, cyclability, and safety of the battery. There are many variables that can affect the composition and properties of the SEI, including the anode material. The SEI has been studied extensively on graphite, an intercalation anode material, and the SEI formed on alloying anodes such as silicon and tin has also been studied in some detail due to their appeal as high energy density anode materials. However, for conversion anode materials such as intermetallics, which offer high energy density without the problems associated with alloying anode materials, there have been few comprehensive studies of the SEI. Little is known about the SEI formed on the intermetallic conversion anode material copper antimonide (Cu2Sb). However, the ability to fabricate thin film Cu2Sb anodes without the use of additives or binders, which can also affect SEI formation, provides an ideal system for studying SEI formation on Cu2Sb. This presentation will highlight work on the systematic study of the SEI formed on Cu2Sb thin film anodes over different potential regions using X-ray photoelectron spectroscopy (XPS).

RMRM 220

1,3,6-Trisubstituted fulvene derived ansa-metallocene ligands: entry to bridged Eu(II) ansa-metallocenes

Sonya K. Adas1,2, [email protected], Gary J. Balaich1. (1) Chemistry & Biochemistry, US Air Force Academy Chemistry Research Center, USAF Academy, Colorado, United States (2) National Research Council, Air Force Research Labs, USAF Academy, Colorado, United States

The reductive coupling of 1,3,6-trisubstituted pentafulvenes results in bridged bis-(cyclopentadienyl) ligands which allow for the synthesis of a versatile group of structurally tunable and sterically demanding ansa-metallocene compounds. Reductive coupling of 1,3-diphenyl-6-(alkyl/aryl)fulvenes (alkyl/aryl = tert-butyl, iso-propyl, phenyl) with aromatic hydrocarbon radical anions give rise to bis-(cyclopentadiene) ligand precursors for the synthesis of bridged ansa-metallocene compounds. These ligand precursors can coordinate a variety of main group-, transition- and lanthanide-metals to afford new ansa-metallocenes. New lanthanide metallocene complexes using Ln(II) (Ln = Yb, Sm, Eu) halides were obtained in this way and structurally characterized by single crystal X-ray diffraction. These are the first reported bridged ansa-metallocene complexes containing Eu(II).

RMRM 221

Theoretical treatment of spin crossover behavior in Fe(II) complexes with iminopyridine ligands

Justin P. Joyce2, [email protected], Matthew P. Shores3, Anthony K. Rappe1, Tarik Ozumerzifon4. (1) Colorado State University, Fort Collins, Colorado, United States (2) Chemistry, Colorado State University, Fort Collins, Colorado, United States (3) Department of Chemistry, Colorado State University, Fort Collins, Colorado, United States

The minute changes in energy between distinct states creates challenges for the reliable simulation of the spin state energetics through computational methods. Toward prediction of systems where guest binding causes spin state switching, Fe(II) iminopyridine complexes were studied experimentally and computationally. The high spin, low spin, and intermediate geometries of a

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synthesized Fe(II) tripodal system were generated. The distortions of the primary coordination sphere associated with spin crossover (SCO) were investigated, and correlated to marked changes in electronic structure. An analogous tris-bidentate complex was synthesized, the spin state properties of which demonstrate the importance of the pendant nitrogen in SCO for orthogonal compounds with a tren backbone. The spin state energetics were calculated through DFT and ab initio methods, and results were validated against experimental values. The results elucidate desirable ligand characteristics to generate SCO behavior.

RMRM 222

Utilizing mixed-linker zirconium based metal-organic frameworks to enhance the visible light photocatalytic oxidation of alcohol

Tian Wei Goh, [email protected]. Iowa State University , Ames, Iowa, United States

A series of mixed-linker zirconium-based metal-organic frameworks (Zr-MOFs) have been synthesized in one-pot reactions. The Zr-MOFs, containing 2-amino-1,4-benzenedicarboxylate (NH2-BDC) as the primary linker and 2-X-1,4-bezenedicarboxylate (X-BDC, X¼H, F, Cl, Br) as a secondary linker, have been used as visible light photocatalysts. The incorporation of multi-functional groups into the catalysts was characterized by PXRD, STEM, NMR, N2 physisorption, diffuse reflectance FTIR, and diffuse reflectance UV–vis. The effects of different linkers on the photocatalytic property of the Zr-MOFs were evaluated in the oxidation of benzyl alcohol. The photocatalytic oxidation reaction was performed using a 26W helical bulb as the visible light source, and the temperature of the reactionwas kept at 80 1C. The Zr-MOF containing mixed NH2-BDC and F-BDC linkers gives five times more conversion in the oxidation of benzyl alcohol compared to the Zr-MOF made of mixed NH2-BDC and H-BDC linkers.We only observed partial oxidation product, benzaldehyde, from the photocatalytic oxidation reaction.

RMRM 223

Investigations into the electronic structure of coordinated ligands pertinent to Cr-photocatalysis

Romeo I. Portillo1, [email protected], Matthew P. Shores2. (1) Chemistry, Colorado State University, Fort Collins, Colorado, United States (2) Department of Chemistry, Colorado State University, Fort Collins, Colorado, United States

The electronic structures of inorganic complexes can provide insight into the reactivity of ground and excited state species in catalytic systems. Recent advances have focused on correct assignment of the oxidation for both the metal ion and ligand. Specifically, a large number of formally “Cr(II)” species have been identified to be Cr(III) ions antiferromagnetically coupled to a ligand radical anion. To understand what role(s) these species may play in Cr-based photcatalysis, we have investigated several heteroleptic chromium polypyridyl [CrIII(phen)2(NN)]3+/2+ and β-diketonato species [CrIII(acac)2(NN)]+/0 and [CrIII(dpm)2(NN)]+/0, all containing a bidentate phenyl iminopyridine ligand (NN = 2-picolylideneaniline). We have characterized both the ligand neutral and anionic ligand radical species in efforts to isolate the radical to a single ligand. These studies suggest that ligands with similar LUMO energy exhibit more delocalization of the radical, inhibiting

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the isolation of a radical on the iminopyridine. Syntheses, spectroscopic, electrochemical and crystallographic data for these and related compounds will be presented.

RMRM 224

Investigating the role of gas-surface interactions in NxOy plasma surface modification of zeolite materials

Angela R. Hanna, [email protected], Ellen R. Fisher. Dept of Chem, Colorado State Univ, Fort Collins, Colorado, United States

An emerging theme in the plasma chemistry community revolves around evaluating and improving the potential effectiveness of low-temperature, inductively coupled plasmas as a method to control atmospheric pollutants. This hinges on the ability to elucidate the underlying chemistry and interactions within a multitude of NxOy plasma systems. Using both temporally and spatially-resolved optical emission and broadband absorption spectroscopies, we have probed energy distributions across multiple degrees of freedom, specifically determining electron, vibrational, and rotational temperatures (Te, TV, and TR, respectively) for N2 (B3Πg ↔ C3Πu) and NO (X2Π ↔ A2Σ+) formed within discharges. Both TV and TR, regardless of precursor, exhibit a strong positive correlation with applied rf power and a negative correlation with system pressure. Te values show little dependence on plasma parameters or source gas, ranging from 1.53 – 1.65 eV; in contrast, TV values are significantly lower than Te (~2,000 - > 3000 K), and TR values are even lower, ranging between ~300 and 1000 K. Formation and destruction mechanisms of plasma species were also explored spectroscopically, thereby not perturbing the plasma environment. Coupling energetic and kinetic information, these data provide unparalleled insight into the overall plasma chemistry and dynamics in NxOy systems, with applications to pollution abatement. We further expanded this study by investigating gas-surface interactions, specifically the influence of both non-catalytic (e.g. Si wafers) and catalytic (e.g. platinum, zeolites) substrates on the gas-phase chemistry of the same plasma systems. This approach to studying the plasma bulk, as well as the gas-surface interface, and corresponding surface analysis, provides the foundation for utilizing plasma processing as a means for NxOy emission control.

RMRM 225

High-pressure response of optical and structural properties in CsPbBr3 and CsPbI3 perovskite nanocrystals

J. C. Beimborn2, [email protected], Pornthip Tongying1, Leah Hall1, Mark Lusk3, Gordana Dukovic1, J. M. Weber2. (1) Dept of Chemistry and Biochemistry, University of Colorado Boulder, Boulder, Colorado, United States (2) JILA and Department of Chemistry and Biochemistry, University of Colorado Boulder, Boulder, Colorado, United States (3) Department of Physics, Colorado School of Mines, Golden, Colorado, United States

Metal halide perovskites have attracted much attention in recent years due to their potential applications in photovoltaics and other optoelectronic devices. We report photoluminescence and optical absorption spectroscopy of CsPbI3 and CsPbBr3 nanocrystals under high hydrostatic pressure. Data was taken up to pressures of 3 GPa using a diamond anvil cell, as well as with a

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hydraulic pressure generator that enables measurement of the lower pressure regions (< 600 MPa) with more detail. We used density functional theory calculations to aid in the interpretation of our data.

RMRM 226

Highly excited states of chlorine substituted cumulenenone series

Quynh L. Nguyen3,4, [email protected], William K. Peters2,4, Margaret M. Murnane3,4, Henry Kapteyn3,4, Ryan C. Fortenberry1. (1) Department of Chemistry, Georgia Southern University, Statesboro, Georgia, United States (2) Physics, University of Colorado - Boulder, Aurora, Colorado, United States (3) Physics, University of Colorado Boulder, Boulder, Colorado, United States (4) JILA, NIST & University of Colorado Boulder, Boulder, Colorado, United States

The electronic states up to the vacuum ultraviolet range (7 - 10 eV) and ionization potentials of the chlorine-substituted cumuleneone series are computed with the coupled cluster methods in order to explore the valence and Rydberg properties of lone-pair terminated, π-conjugated systems in potential resonance with lone pairs from elsewhere in the system. The carbon chain elongation within the family, ClHCnO, influences the electronic excitations, characters, and ionization potentials of the molecules. Comparison between the hydrocarbon and the corresponding chlorine-substituted derivatives give notable similarities between the families. The chlorinated structures analyzed here include formyl chloride, chloroketene, propadienone chloride, and butatrienone chloride. An increase of Rydberg character mixing with valence character is observed, which causes these highly energetic states to be more diffuse and therefore, more challenging to calculate. Thus, we explore the effects of diffuse basis functions, from aug-cc-pV(T+d)Z to t-aug-cc-pV(T+d)Z, to accurately predict the photophysical properties of the systems. The predicted geometries and ionization potentials are in excellent agreement with the experimental photoelectron spectra for formyl chloride and chloroketene. Furthermore, there are similarities in the excitation character between the odd-numbered chains and the even-numbered chains. We predict a kinkiness in the structure of propadienone chloride similar to what is known in allenes while butatrienone chloride interchanges between linearity and non-linearity. Moreover, future implications for sub-femtosecond ultrafast dynamics in highly excited states of polyatomic molecules will be discussed.

RMRM 227

Elucidating energy partitioning trends in hydrocarbon plasmas for plasma-assisted catalysis

Tara L. Van Surksum, [email protected], Ellen R. Fisher. Chemistry, Colorado State University, Fort Collins, Colorado, United States

Plasma-assisted catalysis (PAC) has been investigated as a promising method for pollution control, specifically for conversion or removal of volatile organic compounds. The utility of PAC has been severely limited by an overall lack of understanding of plasma chemistry and the reactions occurring at the plasma-surface interface. The present work investigates fundamental gas-phase chemistry in inductively-coupled hydrocarbon plasma systems to understand energy partitioning in PAC systems for decomposition of volatile organic compounds. Broadband absorption and optical

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emission spectroscopies were utilized to elucidate internal plasma temperatures for multiple species (e.g., CH, C2) in a variety of hydrocarbon-containing plasma systems. For example, in CH4 plasmas, rotational temperatures for CH generally reach values of 1500-2500 K, whereas vibrational temperatures range from ~2000 to ~4500 K under most plasma conditions. Both values appear to be correlated with system pressure and applied rf power. Energy partitioning for the same species has also been evaluated when a catalytic material (e.g., nanostructured SnO2 and TiO2) was placed in the plasma. Properties of plasma-processed materials were also assessed via surface analysis tools (e.g., X-ray photoelectron spectroscopy, scanning electron microscopy). These data will be presented in addition to energy partitioning data to further illuminate the processes occurring at the plasma-catalyst interface. Collectively, these data aim to unravel the complex chemistry of hydrocarbon plasma systems for PAC to become a viable method of pollution control.

RMRM 228

Meuller tensor framework for second harmonic generation of unpolarized light

Fengyuan Deng, [email protected], Changqin Ding, James R. Ulcickas, Garth J. Simpson. Department of Chemistry, Purdue University, West Lafayette, Indiana, United States

A theoretical framework based on bridging the Mueller and Jones frames were introduced to describe the effects of unpolarized components of both the fundamental and SHG. Prediction of polarization dependent SHG from z-cut quartz with unpolarized fundamental was made and validated with experimental measurements. Despite the use of depolarized fundamental, azimuthal orientation and local Jones tensor were successfully recovered for the collagen fibers. Excellent agreements were observed between our measurements with orthogonal methods. SHG microscopy has been a powerful tool for structural characterization of myosin, collagen, microtubule organizations and many other chemical or biological samples. It has provided an attractive alternative to linear methods due to the ability to use near IR excitation which penetrates deeply into thick biological. The specific symmetry requirement of SHG makes polarization dependent SHG measurement sensitive to local orientation and organization of structures. However, the loss of polarization complicates the polarization dependent measurement for deep sample imaging. Traditional interpretations posit the SHG is only generated from the ballistic photons which have not been perturbed by turbid medium. However, generation of SHG measurements under sufficient depolarized situations have been reported. This study may significantly simplify the polarization dependent measurements and provide new interpretations for unpolarized contribution for deep tissue imaging.

RMRM 229

Non-equilibrium dynamics of chloride transport through the E. coli Cl–/H+ antiporter

Chun-Hung Wang, [email protected], Adam W. Duster, MacKenzie G. Zarecki, Hai Lin. Chemistry, University of Colorado Denver, Denver, Colorado, United States

Cl– transport proteins control the selective flow of Cl– ion in regulation of pH, blood pressure, membrane excitability, etc. Malfunction of the ion channel leads to diseases such as myotonia

151

congenital, Bartter syndrome, and epilepsy. We study the Cl– transport pathway in E. coli CLC Cl–/H+ antiporter1 by various MD and QM/MM computational methods.2 Steered molecular dynamics simulation investigates the dragging force of Cl– through the pore. Umbrella sampling is used to estimate the free-energy barrier of Cl– Conduction. The calculated potential of mean force along the translocation path implies the readiness of passing Cl– down the channel, as the barriers are rather small (~3.0 kcal/mol).

RMRM 230

Developing protocol for probing solvation energies of ALSEP extractants

An Ta, [email protected], Govind Hegde, Brian D. Etz, Shubham Vyas. Chemistry, Colorado School of Mines, Golden, Colorado, United States

Management of nuclear waste is a prominent challenge for nuclear power plants. One major concern deals with minor actinides that are produced by the nuclear fuel cycle. These actinides are of one of the largest contributors to the nuclear waste. To reduce the waste, these actinides can be either transmuted into a shorter-lived nuclide or recycled for further energy generation. However, a problem exists within the fact that these actinides are in a mixture containing lanthanides. Currently, the preferred method of separation of actinides from lanthanides is liquid-liquid extraction. With Actinide Lanthanide Separation process (ALSEP) being the most suitable for this process, a significant concern is the kinetic barrier associated with the separation. To improve upon this process, solvation energies of extractants (e.g. HEHEHP, TEHDGA) typically used in the separation of Am/Cm from lanthanides were calculated using a combination of quantum mechanical calculations and molecular dynamics simulations in the aqueous and in the organic phases along with the interfaces. The information acquired from these calculations may help define optimal concentration levels for extraction, in addition, to rationally design next generation of extractants.

RMRM 231

Why Join CCTA and AACT?

Elnore Grow, [email protected]. Retired, Morrison, Colorado, United States

What are the advantages of joining Colorado Chemistry Teachers Association in Colorado or anywhere? What are the advantages of joining American Association of Chemistry Teachers? Today teachers have so many options available, but if they can be told about grants, professional opportunities and classes before they occur, it can help them to be aware of classes in their area that can benefit them. These organizations send eBlasts with the information. Newsletters are too long to be read by most teachers.

152

RMRM 232

Adolescent marijuana use and health effects

Daniel I. Vigil, [email protected]. Marijuana Health Monitoring and Research, Colorado Department of Public Health & Environment, Denver, Colorado, United States

The Marijuana Health Monitoring and Research Program at the Colorado Department of Public Health and Environment monitors marijuana related data in Colorado and current scientific evidence of health effects. This presentation will covers these topics with specific focus on adolescents. It will summarize the scientific evidence on potential health effects of marijuana use by adolescents. Two conclusions are that marijuana use by adolescents adversely affects cognitive abilities and academic achievement. It will also cover data on marijuana use by adolescents in Colorado. For example, 21% of high school students used marijuana in the prior month, and 6% used daily or near-daily. Finally, it will include data on health outcomes in Colorado, specifically calls to the poison center and emergency department visits.

RMRM 233

Scientific approaches to the testing and regulation of cannabis in Colorado

Julia Bramante, [email protected]. Gobi Analytical, Lakewood, Colorado, United States

As the first state to implement the legalization of adult use cannabis, Colorado has been faced with leading the testing and regulation of a brand new industry. How have the regulations behind the quality assurance of cannabis in Colorado been developed? What new advancements are currently being made to optimize these systems? Colorado's booming industry has fostered the potential for novel developments in the testing and science of cannabis, driving policy and research to grow at the same rapid rate.

RMRM 234

Renaissance of Cannabis sativa L.as food, fiber and medicine in the United States

Caren Kershner1,2, [email protected]. (1) Science Chair, Retired, Moffat, Colorado, United States (2) Past-president, Colorado Association of Science Teachers, Villa Grove, Colorado, United States

Cannabis is all over the news these days. Many states have legalized cannabis for medical use and some, like Colorado, have gone a step further, legalizing not only 'marijuana', but also its cousin hemp. Both are classified as Cannabis sativa L., but are marijuana and hemp the same? If not, how do they differ? What are the uses of each plant? What are cannabinoids and how do the percentages vary among cannabis species? Do other plants contain cannabinoids as well? What is the endocannabinoid system (ECS)?

153

Why are some growers using clones rather than seed? What is meant by 'hot' plants? What is the status of Cannabis pharmaceuticals? How can educators comfortably address Cannabis science in the classroom? What are some opportunities that exist for students in the field of Cannabis science and how does chemistry play a part? What are the rules if students want to investigate a property of Cannabis for a science fair project? This workshop will answer these questions and many more, as well as explore the myriad uses of Cannabis and discuss some of the legalities involved with Cannabis cultivation and processing. It will address the chemical differences between marijuana and industrial hemp, and look at some of the factors that influence the expression of different cannabinoids, specifically those of delta9-tetrahydrocannabinol (THC) and cannabidiol (CBD). 30 participants will receive a free kit of industrial hemp products to take back to the classroom to share with their students and all participants will leave feeling more comfortable with the complexities of the cannabis revolution which is occurring throughout the country. This is a current science topic that your students care about- Q&A session will follow the presentation.

2017 National Hemp Association Map of Hemp Cultivation Status in the US

RMRM 235

Marijuana in the emergency department a doctors perspective

Greta Glugoski-Sharp, [email protected]. Science, St. Mary's Academy, Denver, Colorado, United States

Marijuana in the Emergency Department a Doctors Perspective

154

RMRM 236

How to manage and dispose of waste from K-12 science laboratories

Marian O'Connor, [email protected]. Hazardous Materials and Waste Management Division, Colorado Deptment of Public Health and Enviromentt, Arvada, Colorado, United States

Proposal K-12 schools in Colorado are covered by Colorado Code of Regulations (CCR) 1010-6, Rules and Regulations Governing Schools in the State of Colorado and CCR 1007-3, Colorado Hazardous Waste Regulations. CCR 1010-6 applies to chemical products used in the school and CCR 1007-3 applies to waste generated from use of the chemical products. The main objective of this presentation is to help science educators understand the difference between these two regulations and how to comply with both. Secondary objectives are; understanding the terms hazardous substance, hazardous waste, and non-hazardous waste; tools to help determine if the waste is hazardous (listed and/or characteristic), how to dispose of waste in accordance with local and state regulations, disposal options for schools that are practical and cost effective for the school, and how to minimize waste from science laboratories. The CCR 1010-6 has over 200 restricted and prohibited chemicals listed. Science educators in K-12 need to be informed of these regulations and what to expect if the school is inspected. CCR 1007-3 applies to waste produced from science laboratories, including disposal of unused chemicals. Waste can no longer be placed down the drain or into the trash receptacle without completing a hazardous waste determination.

Author Index

AUTHORLASTNAME ABSTRACTNUMBERAbbott,S. RMRM140,141Abdugadar,A. RMRM91Abourahma,J. RMRM8Adams,M. RMRM32Adas,S.K. RMRM49,56,220Adhikari,L. RMRM2Agocs,D. RMRM167Ahsan,S. RMRM69Akam,E.A. RMRM208Anantharam,A. RMRM146Anderson,A. RMRM67Anderson,L. RMRM144Anderson,S.L. RMRM22Anseth,K.S. RMRM151Arnold,A. RMRM11Astashkin,A.V. RMRM208Asunskis,A. RMRM11Asunskis,D. RMRM11Atwood,C.H. RMRM40Audhya,A. RMRM146Auxier,J. RMRM28Auxier,J.D. RMRM28Ayikpoe,R.S. RMRM196Bae,S. RMRM10,68Baines,K.M. RMRM125Baker,G.A. RMRM2Baker,J.L. RMRM150Balaich,G.J. RMRM49,56,220Bardsley,T.A. RMRM147Barr,L. RMRM201,204Barton,H. RMRM17Baxter,E.T. RMRM22Beck,L.R. RMRM180Beimborn,J.C. RMRM225Belmont,E. RMRM77,78Benjamin,J. RMRM208Berliner,L.J. RMRM145Bernholt,S. RMRM88Bertelsen,E.R. RMRM32Berthold,B. RMRM65Bettenhausen,H. RMRM204Beuning,C. RMRM42,95Bhawawet,N. RMRM2Bhowmick,I. RMRM15,166Biros,S.M. RMRM60Bishop,G. RMRM139Black,Z. RMRM74Blakemore,J.D. RMRM43Bodak,E. RMRM121Bonetti,S.J. RMRM14,186,190Boyle,B. RMRM179

AUTHORLASTNAME ABSTRACTNUMBERBraley,J. RMRM30Bramante,J. RMRM233Broeckling,C. RMRM204Browder,C.C. RMRM84,133Brown,C.E. RMRM33,90,156,191, 192,198,199Bruno,T. RMRM143Bunescu,A. RMRM175Burnett,B.J. RMRM8,17Buss,B. RMRM101Bydalek,S. RMRM189,198Cale,T. RMRM189Campanella,A. RMRM206Cardiff,G. RMRM184Carman,M. RMRM10,68Carsella,J. RMRM14,190Carter,C. RMRM11Carver,P.L. RMRM210Cass,A.C. RMRM22Casselman,B. RMRM40Castro,R.S. RMRM150Chang,C.T. RMRM80Chavez,J. RMRM90Chen,A. RMRM38Chen,E.Y. RMRM1Cheng,H.N. RMRM154Chien,T. RMRM21Chon,N. RMRM149ClairII,D. RMRM53Clennan,E.L. RMRM176Coffman,D. RMRM70Cole,C. RMRM70Collins,C. RMRM15,166Conroy,D.T. RMRM152Cook,J. RMRM158Covey,T. RMRM70Crans,D.C. RMRM7,9,14,42,54,95, 138,184,185,187,188, 209,211,212Cranswick,M.A. RMRM53,152Crawford,G. RMRM193Crawford,J. RMRM71,72,75Crick,D. RMRM42,184,185Crick,D.C. RMRM95,138,187,209Cruz,A.J. RMRM10,68,164,208Czerwinski,K. RMRM27Dahl,P. RMRM146Dalton,M. RMRM137Damrauer,N.H. RMRM159Davidjuk,E. RMRM197Davidson,A. RMRM152

156

AUTHORLASTNAME ABSTRACTNUMBERDavidson,M.R. RMRM32Decker,D. RMRM11Delgado,Y. RMRM208Dellinger,S.K. RMRM42DelSesto,R.E. RMRM147,150,195Deng,F. RMRM228Deng,S. RMRM104Deodhar,G. RMRM32,115DePaola,T. RMRM133Depew,A. RMRM10,68Deutsch,T.G. RMRM116,118Diallo,J. RMRM212Diaz,S. RMRM59Didelot,J. RMRM69Dillon,D.L. RMRM120,155Ding,C. RMRM228Dinsmonaite,U. RMRM124Doescher,H. RMRM116Dohoney,R. RMRM137Domaille,D. RMRM174Donadt,T.B. RMRM16,51,58,122,126Dorhout,J.M. RMRM27Döscher,H. RMRM118Doucette,K. RMRM95,188Drogos,D.L. RMRM182,183Druelinger,M.L. RMRM86,155Drysdale,N. RMRM70Dubinets,N. RMRM64Dukovic,G. RMRM225Dunne,C. RMRM131Duster,A.W. RMRM229Eliseeva,S. RMRM207Ellsworth,J.M. RMRM133Ethridge,A. RMRM50Etz,B.D. RMRM172,230Evans,R.C. RMRM61Fan,M. RMRM119Fatur,S.M. RMRM159Fernandez,M. RMRM102Finke,R.G. RMRM161Fisher,E.R. RMRM224,227Flores,R. RMRM76Folkman,S. RMRM161Folsom,J.A. RMRM191Fontes,F. RMRM209Fortenberry,R.C. RMRM226Foster,K. RMRM106Fox,D. RMRM147,150,195Franklin,S. RMRM181Furcolow,C. RMRM142Gage,S. RMRM163Gamage,L.S. RMRM79

AUTHORLASTNAME ABSTRACTNUMBERGarcia,J. RMRM155Garrison,N. RMRM100,132Gaur,K. RMRM208Geisz,J. RMRM116George,S.M. RMRM94Gimble,N.J. RMRM168Giri,R. RMRM6Glover,C. RMRM54Glugoski-Sharp,G. RMRM235Goh,T. RMRM222Gorey,T. RMRM22Gornick,E. RMRM124Graulich,N. RMRM88Greene,J.R. RMRM147,150Grim,J.C. RMRM151Grow,E. RMRM231Gubler,E.A. RMRM187Haase,A. RMRM7,185Hall,H.L. RMRM28Hall,L. RMRM225Hamilton,D. RMRM197Hanna,A.R. RMRM224Hanna,M. RMRM146Hansen,C. RMRM199Haq,M. RMRM124Harris,D. RMRM52Harrison,M.J. RMRM147Hartwell,M. RMRM71,72,75Hartwig,J.F. RMRM175Hassell,K. RMRM47Haugen,M. RMRM139Haynie,T. RMRM104Hegde,G. RMRM230Hendricks,D.W. RMRM117Henry,L.L. RMRM188Herbert,C. RMRM194Hernandez,D. RMRM83,134Herndon,J.W. RMRM79Heuberger,A. RMRM204Heyert,A.J. RMRM150Higgins,R. RMRM216Holbrook,C. RMRM204Horak,K. RMRM142Horn,M.A. RMRM153Hough,J. RMRM185Hu,J. RMRM79Hudson,M.L. RMRM60Hyslop,R.M. RMRM156,189,191,192, 198,199Iacono,S.T. RMRM56Ikeuchi,K. RMRM128Isaak,D. RMRM103,213

157

AUTHORLASTNAME ABSTRACTNUMBERIsenberg,A. RMRM73Ives,J.W. RMRM138Jacobs,M.B. RMRM55,69Jensen,M.P. RMRM26Jensen,M.P. RMRM113Jensen,S. RMRM137,158Joewondo,N. RMRM63Johnson,M.D. RMRM95Johnson,P.A. RMRM96Johnson,S.E. RMRM205Jones,C. RMRM145Joyce,J.P. RMRM221Julin,M. RMRM12Kallan,N.C. RMRM87,136Kapteyn,H. RMRM226Keller,R.S. RMRM147Kemats,K. RMRM37Kershner,C. RMRM234Khanal,P. RMRM173Kim,Y. RMRM124Klas,K. RMRM128Kluherz,K. RMRM32Klundt,D.J. RMRM29Knaus,K.J. RMRM157Knebel,N. RMRM95Knight,J.D. RMRM144,146,148,149Knowles,T. RMRM89Koehn,J.T. RMRM42,54,95,138,187Koppisch,A.T. RMRM147,150,195Kozimor,S.A. RMRM25Kraynak,L.A. RMRM219Kubie,L. RMRM93Landon,J. RMRM127Laster,C.R. RMRM192Latham,J.A. RMRM41Lay,P.A. RMRM54Lee,J. RMRM215Lee,S. RMRM175Leonard,B.M. RMRM160Levina,A. RMRM54Leyva,E. RMRM125Li,Q. RMRM175Lilio,A.M. RMRM16,18,19,51,58, 122Lim,C. RMRM97,178Lin,H. RMRM149,229Lindberg,G.E. RMRM150Liu,B. RMRM178Livesay,B. RMRM57Long,B.A. RMRM22Lopez,J. RMRM62

AUTHORLASTNAME ABSTRACTNUMBERLopez,M. RMRM125Lopez-Bermudez,B. RMRM207Losada,N. RMRM172Loza-Rosas,S.A. RMRM108,208Luca,O.R. RMRM16,18,19,51,58, 122,126Lupardus,R.C. RMRM181Lusk,M. RMRM225Lyons,D. RMRM192Lyons,M.A. RMRM209Ma,J. RMRM214,218Magee,C. RMRM158Mahapatro,S.N. RMRM13,102Malik,H.S. RMRM124Mamiya,B. RMRM38,39Manard,B.T. RMRM31,111Manikoff,J. RMRM152Maricle,B. RMRM68Marshak,M.P. RMRM165Martin,C.G. RMRM122,126Martin,J.P. RMRM65Martinez,D. RMRM71,72,75Mason,D.S. RMRM38,39Mata,S.M. RMRM105Maughan,J. RMRM15,166Mayes,A.M. RMRM120McCann,K. RMRM30McCarthy,B. RMRM82McEvoy,J.P. RMRM102McGrath,A.T. RMRM177McLauchlan,C.C. RMRM9,211McNally,A. RMRM4,48Mendez,A. RMRM108Merenini,P. RMRM81Merrett,K. RMRM150Messman,J. RMRM71,72,75Meyerink,J. RMRM193Michel,B.W. RMRM44Migliori,C.M. RMRM150Millar,A.C. RMRM157Miller,R.C. RMRM217Millward,E. RMRM69,137Mishra,D. RMRM13Mitragotri,S. RMRM150Miyake,G. RMRM3,82,97,98,100, 178,179,180Moctezuma,E. RMRM125Moloney,L.J. RMRM169Moonitz,S. RMRM65Morey,A.M. RMRM110Mosher,M.D. RMRM121,127,154,205

158

AUTHORLASTNAME ABSTRACTNUMBERMurakami,H.A. RMRM9Murnane,M.M. RMRM226Myren,T.H. RMRM16,51Nathaniel,G. RMRM81Negron,L. RMRM208Neilson,J.R. RMRM92,214Nelson,C.R. RMRM123Ngo,C. RMRM163Nguyen,Q.L. RMRM226Nguyen,V. RMRM136Nicki,M. RMRM161Nieto,N.C. RMRM147Noinaj,N. RMRM208Nordlund,D. RMRM163Nunn,A. RMRM92Nye,C.W. RMRM182,183O'Connell,B. RMRM56O'Connor,M. RMRM236Ohlsen,B. RMRM40Ortega-Keshmiri,M. RMRM53Ozumerzifon,T. RMRM221Parkinson,B.A. RMRM93Parks,T.B. RMRM208Pearson,R.M. RMRM98Pecoraro,V.L. RMRM207Peloquin,A. RMRM56Perez,S.C. RMRM208Peters,B. RMRM42,95,184,185, 209Peters,W.K. RMRM226Petoud,S. RMRM207Petry,S. RMRM54Pfeifer,B.A. RMRM195Phillips,P.D. RMRM147Picayo,G. RMRM113Pierce,A. RMRM33Porterfield,D.R. RMRM29Portillo,R.I. RMRM223Prajapati,R. RMRM170Prasad,M. RMRM63Premo,V.L. RMRM26Prenni,J. RMRM204Pribil,S. RMRM76Prieto,A.L. RMRM162,167,168,169, 214,215,217,218,219Pringle,D.L. RMRM181Pullen,N.A. RMRM191,192Pylypenko,S. RMRM24Pylypenko,S. RMRM163Quillinan,S.A. RMRM182,183Ranski,A. RMRM146Rappe,A.K. RMRM221

AUTHORLASTNAME ABSTRACTNUMBERRattner,B.A. RMRM142Reed,S.M. RMRM197Resendiz,M.J. RMRM83,135,194Rex,J. RMRM96Reynolds,M.M. RMRM74Richards,R.M. RMRM23,163,213Richter,A. RMRM10Rim,J. RMRM29Rivero,K.I. RMRM208Rodriguez,D.J. RMRM22Rony,A. RMRM119Rooker,S. RMRM209Rose,B.T. RMRM79Rubush,D.M. RMRM99,124,129Ryan,M.D. RMRM100Saidov,M. RMRM85Sambur,J. RMRM20,61,73Sambur,J.B. RMRM112Samp,E. RMRM203SanchezLombardo,I. RMRM14Sandoe,H. RMRM59Sarathy,J. RMRM124Savage,P. RMRM104,105,173Savani,P.P. RMRM195Saxena,M. RMRM208Schelble,S.M. RMRM85,158Schenk,N. RMRM146Schneider,J.D. RMRM214Schoffstall,A.M. RMRM86,107,177Schofield,B.A. RMRM190Schottler,S.B. RMRM121Schubert,D.M. RMRM55Schulze,M. RMRM162Schutt,T. RMRM172Schwenz,R.W. RMRM34Seas,M. RMRM96Sedin,D.L. RMRM200,204Selman,M. RMRM212Shafer,J. RMRM32Sharma,S. RMRM208Sharp,L. RMRM83,134Shepard,S.G. RMRM159Shores,M.P. RMRM57,221,223Shulda,S. RMRM163Simmons,L.F. RMRM150Simpson,G.J. RMRM228Sitarik,I. RMRM66Skinner,A. RMRM135Slipchenko,L.V. RMRM64Smith,M. RMRM56Solis,G. RMRM198Sorauf,K. RMRM13

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AUTHORLASTNAME ABSTRACTNUMBERSorauf,K.J. RMRM76Spotts,T. RMRM148Stahl,R.S. RMRM142Stahlfeld,K. RMRM77,78Staver,J. RMRM74Steiner,M. RMRM118Stewart,K.A. RMRM107Stinson,T.A. RMRM51,58,126Stuart,M. RMRM202Sturgell,J. RMRM83,134Suiter,C. RMRM143Suits,J.P. RMRM36,37,89,91Sun,Z. RMRM119Sweitzer,A. RMRM156Ta,A. RMRM230Tandon,L. RMRM29,31Tarlton,M. RMRM211Tassone,C. RMRM163Tekletsadik,K.H. RMRM35Thielman,J.R. RMRM130Thode,J.M. RMRM160Thomas,D.C. RMRM195Tinoco,A.D. RMRM12,108,208Todt,M.A. RMRM73Tomat,E. RMRM208Tongying,P. RMRM225Tran,H.T. RMRM144Tran,S. RMRM149Trewyn,B.G. RMRM32,115,213Trujillo,B.J. RMRM186Turner,J.A. RMRM116,118Ulcickas,J.R. RMRM228Urynowicz,M. RMRM182,183VanCleave,C. RMRM42,95,185VanHoomissen,D.J. RMRM45,46Vanitcha,A. RMRM171VanSurksum,T.L. RMRM227Vavrek,T. RMRM99,129Vazquez,A.M. RMRM208Vazquez,A.L. RMRM208Vigil,D.I. RMRM232Vyas,S. RMRM45,46,172,230Wackerle,B. RMRM60Wagle,D. RMRM2Wallace,C.A. RMRM9,211Wang,C. RMRM229Wang,H. RMRM83Wang,W. RMRM5Wardle,D. RMRM121Watkins,K. RMRM93Watson-Siriboe,A. RMRM148Watzky,M. RMRM50

AUTHORLASTNAME ABSTRACTNUMBERWatzky,M. RMRM59,114Wawrousek,K. RMRM77,78,96,182,183Weber,J.M. RMRM225Weber,J.A. RMRM176Weinrich,M. RMRM88Werner,E.J. RMRM60Whaley,B. RMRM156Widegren,J. RMRM143Williams,N. RMRM49Williams,R.M. RMRM128,130,131Wylie,E.M. RMRM31,111Xu,N. RMRM31,111Yang,L. RMRM7,42Yang,X. RMRM7Yin,Y. RMRM79Yokley,R.A. RMRM154York,A.M. RMRM213Young,J.L. RMRM116,118Zadrozny,J. RMRM109Zakrewsky,M. RMRM150Zarecki,M.G. RMRM229Zayas,A. RMRM108Zhao,H. RMRM81Zhao,L. RMRM131Zheng,Y. RMRM119Zhou,J. RMRM62Zhou,M. RMRM161Zou,Y. RMRM62

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