III School for young scientists Magnetic Resonance and ... · 8 Theory of the pulse electron double resonance spectroscopy K.M. Salikhov ... Plasticity in protein-DNA recognition:

1

Institute of Chemical Kinetics and Combustion

International Tomography Center

Faculty of Natural Sciences Novosibirsk State University

III School for young scientists

Magnetic Resonance and Magnetic

Phenomena in Chemical and Biological

Physics

Book of abstracts

Novosibirsk 2014

2

Organizers

Institute of Chemical Kinetics and

Combustion of the Siberian

Branch of the Russian Academy

of Sciences

International Tomography Center

of the Siberian Branch of the

Russian Academy of Sciences.

Faculty of Natural Sciences

Novosibirsk State University

Sponsors

Russian Foundation for Basic

Research

3

Organizing Committee

Victor A. Bagryansky – Chairman

Leonid V. Kulik – Vice-chairman

Petr A. Purtov – Vice-chairman

Tatiana Yu. Karogodina – Scientific Secretary

Elena G. Bagryanskaya

Konstantin L. Ivanov

Daniil I. Kolokolov

Irina S. Tretyakova

Nikolay P. Isaev

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Program

September 7

9.00 – 13.00 Registration, arrival

12.30-14.00 Lunch

14.00 – 14.10 Opening of the School.

14.10 – 14.30 Voevodsky Prize awarding ceremony

Lectures Chairman - Gerd Kothe

14.30 – 15.30 Kev Salikhov (Kazan, Russia) "Theory of the pulse electron double

resonance spectroscopy"

15.30 – 16.30 Maxim Yulikov (Zurich, Switzerland) "Studies of structure and

conformational changes of biomacromolecules and their complexes: pulse EPR

techniques based on static and stochastic electron-electron dipolar interaction"

16.30 – 17.00 Coffee break

Lectures Chairman – Ulrich Steiner

17.00 – 18.00 Michael K. Bowman (Alabama, USA) "Measurement of hyperfine

couplings by pulsed EPR"

18.00 – 19.00 Sergey A. Dzuba (Novosibirsk, Russia) "Structure and dynamics of spin-

labeled biological systems"

19.00 - … Welcome party

September 8

Lectures Chairman – Hans-Martin Vieth

9.00 – 10.00 Robert Kaptein (Utrecht, the Netherlands) "Protein-DNA interaction: how

do proteins find their target?"

10.00 – 11.00 Christian Griesinger (Goettingen, Germany) "Protein dynamics and

neuroprotection: Approaches by NMR"


Lectures Chairman – Sergey Dzuba

11.30 – 12.30 Gerd Kothe (Freiburg, Germany) "Nuclear hyperpolarisation and spin

entanglement in photoexcited triplet states"

12.30 – 13.30 Peter Tolstoy (Saint Petersburg, Russia) "Cooperativity of functional

hydrogen bonds in active sites of enzymes: NMR study of model systems"

13.30-15.00 Lunch

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14.00 – 16.00 Cultural program (Excursion to Open-air Historical and Architectural

Museum)

16.00 – 18.00 Free time

18.00 – 20.00 Poster session

September 9 Lectures Chairman – Christian Griesinger

9.00 – 10.00 Torsten Gutmann (Darmstadt, Germany) "Investigation of structure and

surface chemistry of heterogeneous catalysts employing advanced solid-state NMR

techniques"

10.00 – 11.00 Olga Lapina (Novosibirsk, Russia) "Advanced solid state NMR

spectroscopy for structural characterization of supported catalysts"


Lectures Chairman – Maxim Yulikov

11.30 – 12.30 Anatoly Dvurechenskii (Novosibirsk, Russia) "Spin resonance of

electrons localized in Ge/Si quantum dot nanoheterostructures"

12.30 – 13.30 Jan Behrends (Berlin, Germany) "EPR in solar cell research"

13.30-15.00 Lunch

Oral presentations by young scientists Chairman – Nikolay Isaev

15.00 – 15.20 Fedor Mushenok (Chernogolovka, Russia) “FMR study of Cr1/3NbS2

helical magnet”

15.20 – 15.40 Alexandr Chushnikov (Kazan, Russia) “Possibilities of EPR diagnostics

for monitoring the sportsmen’s state of health”

15.40 – 16.00 Anatoly R. Melnikov (Novosibirsk, Russia) “Highly efficient exciplex

formation in case of X-ray irradiation of non-polar solutions”

16.00 – 16.20 Andrey N. Pravdivtsev (Novosibirsk, Russia) “Exploiting Level Anti-

Crossings in the rotating frame for transferring spin hyper polarization”

16.20 – 16.40 Kirill Levin (Winnipeg, Canada) “Experimental and theoretical NMR

analysis of paramagnetic M(acac)3 (M = Cr, Mn) coordination compounds”

16.40 – 17.00 Irina Yu. Barskaya (Novosibirsk, Russia) “The EPR study of light-

induced thermally inaccessible spin state in copper-nitroxide based molecular magnet”


Oral presentations by young scientists Chairman – Daniil Kolokolov

17.30 – 17.50 Elena Tupikina (Saint-Petersburg, Russia) “Proton transfer process in C-

H···X hydrogen bonds”

17.50 – 18.10 Alekper Huseynzada (Baku, Azerbaijan) “Investigation of some

acetophenone derivatives in solution by NMR”

18.10 – 18.30 Alexey Chubarov (Novosibirsk, Russia) “Fluorinated homocysteine

derivatives as potential molecular probes for 19

F magnetic resonance spectroscopy and

imaging: synthesis and characterization”

18.30 – 18.50 Alexander Khudozhitkov (Novosibirsk, Russia) “2H NMR study of the

rotational dynamics of terephatalate phenylenes in metal-organic frameworks CoMOF,

NiMOF and ZnMOF: effect of different metal centers”

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18.50 – 19.10 Olga Selyutina (Novosibirsk, Russia) “Influence of glycyrrhizin on cell

membrane properties”

19.10 – 19.30 Danila Barskiy (Novosibirsk, Russia) “Low-field NMR spectroscopy and

imaging via parahydrogen based hyperpolarization: Towards catalyst-free molecular

contrast agents and MRI of industrial hydrogenation”

September 10 Lectures Chairman – Michael Bowman

9.00 – 10.00 Ulrich E. Steiner (Konstanz, Germany) "Spin-orbit-coupling based spin

chemistry"

10.00 – 11.00 Kiminori Maeda (Saitama, Japan) "Magnetoreception of molecular

systems and spin selective chemical reactions"


Lectures Chairman – Robert Kaptein

11.30 – 12.30 Hans-Martin Vieth (Berlin, Germany) "The role of level-anti-crossings in

spin hyperpolarization"

12.30 – 13.30 Alexandra Yurkovskaya (Novosibirsk, Russia) "Time-resolved and field

dependent CIDNP"

13.30-15.00 Lunch

15.00 – 19.00 Practical work. Tutorial on pulse EPR and NMR spectrometers (parallel)

19.00 - … Banquet

September 11 Lectures Chairman – Leonid Kulik

10.00 – 11.00 Tatyana Leshina (Novosibirsk, Russia) "The study of radical stages

practically important processes by methods of spin chemistry"


Lectures Chairman – Leonid Kulik

11.30 – 12.30 Nikolay Polyakov (Novosibirsk, Russia) "Application of NMR in medical

research"

12.30 – 13.30 Anatolii Vanin (Moscow, Russia) "EPR analysis of biologically active

dinitrosyl iron complexes with thiolate ligands"

13.30-15.00 Lunch

15.00 – 15.30 Closing of the School

15.30 Group photo

7

LECTURES

8

Theory of the pulse electron double resonance spectroscopy

K.M. Salikhov

Zavoisky physical-technical institute of Russian academy of sciences, Kazan

420029, Russian Federation

E-mail: [email protected]

Content of the lecture

1. Survey of the early years studies of the electron spin-spin interaction using pulse EPR

methods.

2. Current theory of the pulse electron double resonance spectroscopy

3. Recent development of the pulse electron double resonance (PELDOR) spectroscopy

theory

4. Perspectives of PELDOR in studying structure in nanoscale region

References

[1] K.M. Salikhov, A.G. Semenov, Yu.D. Tsvetkov. Electron spin echo and its

applications. Nauka, Novosibirsk (1976)

[2] Milov A.D., Salikhov K.M., Schirov M.D., Fiz. Tverd. Tela 23, pp. 975-982 (1981)

[3] Spiess H.W. J. Magn. Reson.213, pp. 326-328 (2011)

[4] Salikhov K.M., I.T. Khairuzhdinov I.T., Zaripov R.B.. Appl. Magn, Reson. 45, pp.

573-620 (2014)

Lectues, September 7, 14:30 Lecture, September 7, 14:30

9

Studies of structure and conformational changes of

biomacromolecules and their complexes: pulse EPR

techniques based on static and stochastic electron-electron

dipolar interaction

Maxim Yulikov

ETH Zurich, Department of Chemistry and Applied Bioscience, Laboratory of Physical

Chemistry, Vladimir Prelog Weg 2, 8093, Zurich, Switzerland


Over the last two decades pulse EPR techniques attract growing attention as a tool

for determination of structure and for studies of conformational changes of

biomacromolecules and their complexes. Paramagnetic centers can be introduced to a

biomacromolecule by the so-called site-directed spin labeling (SDSL) technique, based

on chemically-specific attachment of paramagnetic labels at selected and appropriately

modified sites in a biomolecule under study. The magnetic dipolar interaction between

two spin labels encodes distance between them, and the measurement of this interaction

can thus provide a constraint for the distance between the two labeling sites.

The most broadly used approach exploits different types of nitroxide radicals for

spin labeling and pulse electron-electron double resonance (abbreviated as PELDOR or

DEER) for distance measurements. While PELDOR/DEER experiments, based on the

measurement of static dipolar interaction, are the most broadly spread, other pulse EPR

experiments to measure static (double quantum coherence (DQC)) or stochastic dipolar

interaction (relaxation enhancement (RE), relaxation induced dipolar modulation

enhancement (RIDME)) can be used.

During the previous few years pulse EPR experiments with non-identical spin label

pairs that significantly differ in their spectroscopic properties have been intensively

studied. While PELDOR/DEER technique is considered to be the most appropriate in

measurements of nitroxide-nitroxide distances, for the new combinations of spin labels

other experiments might be more favorable. In this lecture we will overview some

distance measurement experiments in pulse EPR with a particular accent on

measurement of stochastic dipolar interactions in pairs of identical and non-identical

(‘spectroscopically orthogonal’) spin labels.

Lecture, September 7, 15:30

10

Measurement of Hyperfine Couplings by Pulsed EPR

Michael K. Bowman

Department of Chemistry, The University of Alabama, Tuscaloosa, Alabama 35487-0336

USA

E-mail:[email protected]

Hyperfine couplings between an unpaired electron and nuclear spins are an

important source of information about the electronic and physical structure of

paramagnetic species. The unpaired spin density, the partially-occupied molecular

orbitals, and the physical structure can all be probed through hyperfine couplings.

A brief introduction to hyperfine coupling tensors will be presented, with a more

detailed look at how they behave in systems with large g-factor anisotropy. The

measurement of hyperfine tensors by pulsed EPR measurements based on electron

nuclear double resonance (ENDOR) and electron spin echo envelope modulation

(ESEEM) will be presented. Practical approaches to extraction of hyperfine tensors

from one- and two-dimensional ESEEM, including HYSCORE will be demonstrated.

The two common forms of pulsed ENDOR developed by Mims and Davies will be

described and important experimental parameters affecting the spectral shapes will be

illustrated.

This work is supported by NSF-RFBF Grant 14-03-93180 and National Institutes of

Health HL095820 and GM110790.


11

Pulsed EPR of Spin-Labeled Biological Systems

Sergei A. Dzuba

Voevodsky Institute of Chemical Kinetics and Combustion, Russian Academy of

Sciences, Institutskaya, 3, 630090 Novosibirsk, Russia

and Novosibirsk State University,Pirogova 2, 630090 Novosibirsk, Russia


Methods of pulsed EPR based on electron spin echo (ESE) spectroscopy include

ESE envelope modulation (ESEEM) induced by electron-nuclei interactions, electron-

electron double resonance (PELDOR or DEER) induced by electron-electron

interactions, ESE signal decay induced by molecular motions, and others. Their

applications to study various biological systems using spin labels and probes provides

information on the conformations of peptides, proteins, DNAs and other biomolecules,

supramolecular structure of biological membranes and other multicomponent systems,

the orientational cooperative dynamics of molecules in disordered media and others.


12

Protein-DNA interaction: how do proteins find their target?

Robert Kaptein

Bijvoet Centre, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands

e-mail: [email protected]

The E.coli lac repressor is a text-book example of a bacterial gene regulatory

protein. Our NMR studies of the structure and dynamics of complexes of a dimeric lac

headpiece with lac operator DNA have provided a detailed picture of how the various

lac operator sequences are recognized (1).

We have also addressed the problem of non-specific DNA interaction and the NMR

structure of dimeric headpiece with a non-operator DNA has been solved (2). Generally,

these non-specific interactions are assumed to be crucial for rapid target-site location by

DNA-binding proteins. The NMR structure of the non-specific lac headpiece-DNA

complex suggested how the repressor searches for its target site by sliding along random

DNA and binds to the operator through a folding-coupled-to-binding transition (2).

However, surprisingly the 1D diffusion constant for sliding on DNA obtained from

NMR line-broadening is much smaller than that determined by single-molecule

fluorescence methods and cannot account for an enhanced target location by lac

repressor (3). In the lecture I will discuss possible reasons for this discrepancy.

References

1a. C.G. Kalodimos, A.M.J.J. Bonvin, R. Kopke Salinas, R. Wechselberger, R.

Boelens and R. Kaptein, “Plasticity in protein-DNA recognition: lac repressor interacts

with its natural operator O1 through alternative conformations of its DNA-binding

domain” , EMBO J. 21 (2002), 2866-2876.

1b. J. Romanuka, et al., “Specificity and Affinity of Lac Repressor for the

Auxiliary Operators O2 and O3 Is Explained by the Structures of Their Protein-DNA

Complexes”, J.Mol.Biol. 390 (2009), 478-489.

2. C.G.Kalodimos, et al., “Structure and Flexibility Adaptation in Nonspecific and

Specific Protein-DNA Complexes”, Science 305 (2004), 386-389.

3. K. Loth et al., “Sliding and target location of DNA-binding proteins: an NMR

view of the lac repressor system”, J.Biomol. NMR 56 (2013) 41-49.


13

Protein dynamics and Neuroprotection: Approaches by NMR

David Ban1, Colin Smith

1,2, Supriya. Pratihar

1, T. Michael Sabo

1, Sergey Ryazanov

1,3,

Andrei Leonov1, Saskia Villinger

1, Robert Schneider

1, Luigi Russo

1,Maestre, Mitcheell

1,

Vytautas. Gapsys2, Jan Hennig

2, R. Bryn Fenwick

4, Korvin F. A. Walter

1, Karin Giller

1,

Stefan Becker1, Xavier Salvatella

4, Berend L. de Groot

2, Armin Giese

5, Markus

Zweckstetter1,3

, Adam Lange1, Donghan Lee

1, C. Griesinger

1

1NMR based Structural Biology and

2Theoretical and computational biophysics, Max

Planck Institute for Biophysical Chemistry, Göttingen, Germany,3CNMPB

Göttingen,4Laboratory of Molecular Biophysics, ICREA and Institute for Research in

Biomedicine Barcelona, Barcelona, Spain

The possibility to explore dynamics of proteins specifically ubiquitin which

promiscuously recognizes many binding partners will be presented based on the

accurate measurement of anisotropic parameters such as residual dipolar couplings (1).

This approach allows to characterize at unprecendented detail the ground state ensemble

of the protein (2). Modulation of the distributions of conformations within the ground

state ensemble by mutations that do not involve the binding interface allows to make

ubiquitin more specific to recognition proteins (3). Rates of interconversion between

ground state ensemble members have been measured by low temperature relaxation

dispersion (4), dielectric relaxation and temperature jump SAXS and were compared to

MD results (5). Further, with high-power relaxation dispersion measurements (6) it is

possible to characterize motion kinetically to one digit µs time scales. With these

measurements a rotamer shuffling for the side chains is detected that occurs both for

ubiquitin and protein G.

Similar approaches can be used to characterize motion of membrane proteins and

multidomain proteins as shown on the examples of VDAC (7) and Calmodulin/peptide

complexes (8).

In a second part of the presentation, NMR results and beyond are presented towards

neuroprotective strategies in Parkinson’s and Alzheimer’s disease in which lipophilic

small molecules (9) are effective in various animal models of the diseases. They change

the aggregation landscape of the proteins populating and interfere with membrane pore

formation by these proteins.

References

1) Peti, W., Meiler, J., Brüschweiler, R. and Griesinger ,C. (2002)

Model free Analysis of Protein Backbone Motion from Residual Dipolar Couplings. J. Am.

Chem. Soc. 124, 5822-5833; T. M. Sabo, C. A. Smith, D. Ban, A. Mazur, D. Lee, C.

Griesinger, „Orium: Optimized RDC based Iterative and Unified Model-free analysis” J.

Biomol. NMR 127, 287-301 (2014)

2) Lange, O., Lakomek, N. A., Farès, C., Schröder, G.,Becker, S., Meiler, J., Grubmüller, H.,

Griesinger, C., de Groot, B.: Recognition dynamics up to microseconds revealed from an

RDC-derived ubiquitin ensemble in solution. Science, 2008, 320, 1471-1475


14

3) Servaas Michielssens, Jan Henning Peters, David Ban, Supriya Pratihar, Daniel Seeliger,

Monika Sharma, Karin Giller, Thomas Michael Sabo, Stefan Becker, Donghan Lee,

Christian Griesinger, and Bert L. de Groot, A Designed Conformational Shift To Control

Protein Binding Specificity, Angew. Chem. Int Ed. In press 2014

4) Ban, D., M.F. Funk, R. Gulich, D. Egger, T. M. Sabo, K.F.A. Walter, R. B. Fenwick, K.

Giller, F, Pichierri, B.L. de Groot, O. F. Lange, H. Grubmüller, X. Salvatella, M. Wolf, A.

Loidl, R. Kree, S. Becker, N.-A. Lakomek, D. Lee, P. Lunkenheimer, C. Griesinger: Kinetics

of Conformational Sampling in Ubiquitin. Angew. Chem. Int. Ed. 50, 11437-11440 (2011)

5) Shaw, David E.; Maragakis, Paul; Lindorff-Larsen, Kresten; Piana, Stefano; Dror, Ron O.;

Eastwood, Michael P.; Bank, Joseph A.; Jumper, John M.; Salmon, John K.; Shan, Yibing;

Wriggers, Willy. Atomic-Level Characterization of the Structural Dynamics of Proteins.

Science 330, 341-346 (2010)

Fenwick, R.B., Esteban-Martin, S ., Richter, B ., Lee, D ., Walter, K.F.A., Milovanovic, D.

Becker, S., Lakomek, N.A., Griesinger, C ., Salvatella, X.: Weak Long-Range Correlated

Motions in a Surface Patch of Ubiquitin Involved in Molecular Recognition. Journal of the

American Chemical Society 133, 10336-10339 (2011)

6) Ban, David, A. D. Gossert, K. Giller, S. Becker, C. Griesinger and D. Lee: Exceeding the

limit of dynamics studies on biomolecules using high spin-lock field strengths with a

cryogenically cooled probehead. Journal of Magnetic Resonance, 221, 1- 4 (2012)

7) Bayrhuber, M., Meins, T., Habeck, M., Becker, S., Giller, K., Villinger, S., Vonrhein, C.,

Griesinger, C., Zweckstetter, M. and Zeth, K. (2008) Structure of the human voltage-

dependent anion channel, Proceedings of the National Academy of Sciences of the United

States of America, 105 (40): 15370-15375

Villinger, S., Briones, R., Giller, K., Zachariae, U., Lange, A., De Groot, B. L., Griesinger,

C., Becker, S. and Zweckstetter, M. (2010)

Functional dynamics in the voltage-dependent anion channel, Proceedings of the National

Academy of Sciences of the United States of America, 107 (52): 22546-22551; Schneider,

R., Etzkorn, M., Giller, K., Daebel, V., Eisfeld, J., Zweckstetter, M., Griesinger, C., Becker,

S. and Lange, A. (2010)

The Native Conformation of the Human VDAC1 N Terminus, Angewandte Chemie-

International Edition, 49 (10): 1882-1885; Villinger, S., Briones, R., Giller, K., Zachariae,

U., Lange, A., De Groot, B. L., Griesinger, C., Becker, S. and Zweckstetter, M. (2012)

Functional dynamics in the voltage-dependent anion channel, Febs Journal, 279 433-433;

Villinger, Saskia; Giller, Karin, Bayrhuber, Monika, Lange, Adam, Griesinger, Christian,

Becker, Stefan, Zweckstetter, Markus, Nucleotide Interactions of the Human Voltage-

dependent Anion Channel J. Biol. Chem. 289, 13397-13406 (2014)

8) Russo, Luigi, Maestre-Martinez, Mitcheell, Wolff, Sebastian, Becker, Stefan, Griesinger,

Christian, Interdornain Dynamics Explored by Paramagnetic NMR; J. Am. Chem. Soc. 135,

17111-17120 (2013)

9) Giese, Bertsch, Habeck, Wagner, Weber, Kretzschmar, Hirschberger, Tavan, Geissen,

Groschup, Griesinger, Leonov, Ryazanov; WO 2010/000372 A2, Jan. 7. 2010

J. Wagner, S. Ryazanov, A. Leonov, J. Levin, S. Shi, F. Schmidt, C. Prix, F. Pan Montojo,

U. Bertsch, G. Mitteregger-Kretzschmar, M. Geissen, M. Eiden, F. Leidel, T. Hirschberger,

A.A. Deeg, J.J. Krauth, W. Zinth, P. Tavan, J. Pilger, M. Zweckstetter, T. Frank, M. Bähr,

J.H. Weishaupt, M. Uhr, H. Urlaub, U. Teichmann, M. Samwer, K. Boetzel, M. Groschup,

H. Kretzschmar, C. Griesinger, A. Giese, Acta Neuropath. 125, 795-813 (2013)

Levin, Johannes, Schmidt, Felix, Boehm, Cathrin, Prix, Catharina, Boetzel, Kai, Ryazanov,

Sergey , Leonov, Andrei, Griesinger, Christian, Giese, Armin, The oligomer modulator

anle138b inhibits disease progression in a Parkinson mouse model even with treatment

started after disease onset. Act. Neuropath. 127, 779-780 (2014)

15

Nuclear Hyperpolarization and Spin Entanglement in

Photoexcited Triplet States

Gerd Kothe

Department of Physical Chemistry, University of Freiburg, Freiburg 79104,

Germany


In this lecture, I should like to discuss two novel quantum mechanical mechanisms

which generate nuclear hyperpolarization in photoexcited triplet states. The first

mechanism is the basic mechanism which applies to any given field strength and

orientation. The second mechanism induces electron and nuclear hyperpolarization only

at level anti-crossing (LAC) conditions. Here, we explore these two mechanisms using

pulsed magnetic resonance in combination with pulsed laser excitation.

Recently, nuclear quantum oscillations have been detected in an organic triplet state

subject to an external magnetic field.1 Analysis reveals that the nuclear spins participate

in the intersystem crossing process. The novel mechanism also acts as a source of

oscillatory nuclear spin polarization which gives rise to NMR signal enhancement even

at very high magnetic fields.1

This opens new perspectives for the analysis of photo-

CIDNP in mechanistic studies of photoactive proteins. Here, we report on magnetic

field dependent 13

C NMR studies of the blue light receptor phototropin demonstrating

that a triplet state is the major photo-CIDNP source.2

More than 35 years ago, nuclear hyperpolarization has been observed in organic

triplet states at LAC conditions.3,4

Here, we identify the underlying mechanism

employing phosphorescent crystals. First, a laser pulse generates the triplet state and

initiates the formation of multipartite entanglement between the electron spin and all

hyperfine coupled nuclear spins. This gives rise to huge oscillatory electron and nuclear

spin polarization. Then, by the action of a resonant high-power microwave pulse, the

electron spin is disentangled from the nuclear spins. As a result, the longitudinal nuclear

magnetization evolves separately under the nuclear spin Hamiltonian. Due to robust

entanglement of the nuclear spins, one observes quantum oscillations at the nuclear

Larmor frequency. Thus, at triplet LAC conditions, strongly entangled nuclear spin

states are created simply by light excitation. Because of the huge polarization, generated

at LAC, these quantum systems are capable of room temperature operation. This makes

them promising candidates for various applications in quantum information processing.

[1] Kothe G., Yago T., Weidner J.-U., Link G., Lukaschek M. and Lin T.-S. J. Phys.

Chem B 2010, 114, 14755-14762.

[2] Kothe G., Lukaschek M., Link G., Kacprzak S., Illarionov B., Fischer M.,

Eisenreich W., Bacher A., Weber S., unpublished results.

[3] Veeman, W.S., van der Poel, A.L.J. and van der Waals J.H. Mol. Phys. 1975, 29,

225-248.

[4] Colpa, J.P. and Stehlik D. Chem. Phys. 1977, 21, 273-288.


16

Cooperativity of Functional Hydrogen Bonds in Active Sites

of Enzymes: NMR Study of Model Systems

Peter M. Tolstoy,1 Monique Chan-Huot,

2 Sharif Shasad,

2 Michael D.

Toney,3 Ilja G. Shenderovich,

4 Gleb S. Denisov,

5 Hand-Heinrich Limbach

2

1 Institute of Chemistry, St. Petersburg State University, Universitetskij pr. 26, 198504 Peterhof, Russia

2 Institut für Chemie und Biochemie, Freie Universität Berlin, Takustr. 3, 14195 Berlin, Germany

3 Department of Chemistry, University of California-Davis, 95616 Davis, USA 4 University of Regensburg, Universitätsstr. 31, 93040 Regensburg, Germany

5 Institute of Physics, St. Petersburg State University, Universitetskij pr. 26, 198504 Peterhof, Russia

[email protected]

In this presentation we discuss geometric hydrogen bond cooperativity effects in

view of their role in enzymatic catalysis. In many enzymes, such as Photoactive Yellow

Protein (PLP), Aspartic Proteases (such as chymotrypsin or HIV-1 Pr), vitamin B6-

dependent enzymes (f.e. aspartate aminotransferase, AspAT) and many others, the

mechanism of catalysis requires two or more H-bonds to mutually influence each other

(i.e. displacement of the bridging proton in one of the H-bonds changes the proton

position in the other one), thus facilitating certain chemical reactions.

Firstly, a short overview of the NMR-based research of H-bond structure and

geometry will be given. Secondly, we will present a series of model systems mimicking

H-bond motifs in active sites of PYP (Figure, left) and AspAT (Figure, right). The

results and predictions of the NMR studies on model systems will be followed by the

investigation of the actual biomolecule. We conclude that NMR approach based on

model systems can help in localizing functional bridging protons and deducing catalytic

mechanisms.

NH2

HO2C RH

“internal aldimine” “external aldimine”

Lysine enyzme

H3N

transimination

AspAT PYP

O S

O

H H

OTyrO

OGlu

H

O

Thr

O

O S

H

446 nm

h

darkstate

signallingstate

This work was partially funded by RFBR grant 14-03-00111, as well as by the German-

Russian Interdisciplinary Science Center (G-RISC) funded by the DAAD.


17

Investigation of Structure and Surface Chemistry of

Heterogeneous Catalysts employing Advanced Solid-State

NMR Techniques

Torsten Gutmanna, Liu Jiquan

a, Niels Rothermel

a, Karine Philippot

b, Bruno

Chaudretc, Hergen Breitzke

a, and Gerd Buntkowsky

a.

a TU Darmstadt; Eduard-Zintl-Institut für Anorg. und Phys. Chemie, Petersenstraße 20,

D-64287 Darmstadt, Germany

e-Mail: [email protected]

b Université de Toulouse; UPS, INPT; LCC; 205 Route de

Narbonne, F-31077 Toulouse, France

c Université de Toulouse; INSA, UPS, CNRS; LPCNO, 135 avenue de Rangueil, F-31077 Toulouse,

France nk line)

In recent years, a large number of catalytically active hybrid materials organized on

the meso- and nanoscale such as immobilized homogeneous catalysts or metal

nanoparticles (MNPs) have been developed and investigated. Such heterogeneous

catalysts are important due to their high application potential for environmental friendly

organic transformations and easy recyclability. Solid-state NMR spectroscopy has

evolved into an important tool for the characterization of the structure of these

heterogeneous catalysts and the chemical processes on their surface.

The main part of the lecture presents recent examples for structure investigations of

immobilized catalysts containing rhodium or ruthenium employing standard solid state

NMR techniques 1-3

and signal enhanced dynamic nuclear polarization (DNP)

experiments. Furthermore, the analysis of binding sites and the interaction between

ligands and small probe molecules on the surface of ruthenium MNPs employing cross

polarization (CP) and rotational echo double resonance (REDOR) experiments is

demonstrated.4 These distance informations are important to understand their behavior

in catalytic reactions. Finally, some recent advances of temperature dependent studies of

ruthenium MNPs are shown which shed more light on the structure and dynamics of

hydrogen/deuterium on the surface of these particles.

(1) Gutmann, T., Gruenberg, A., Rothermel, N., Werner, M., Srour, M.,

Abdulhussain, S., Xu, Y., Breitzke, H., Buntkowsky G., Solid State NMR 55-56,

(2013), 1-11

(2) Grünberg, A., Gutmann, T., Rothermel, N., Xu, Y., Breitzke, H., Buntkowsky G.,

Z. Phys. Chem. 227, (2013), 901-915

(3) Abdulhussain, S., Breitzke, H., Ratajczyk, T., Grünberg, A., Srour, M., Arnaut, D.,

Weidler H., Kunz, U., Kleebe, H. J., Bommerich, U., Bernarding, J., Gutmann, T.*,

Buntkowsky, G, Chem. Eur. J. 20, (2014), 1159-1166

(4) Gutmann, T., Bonnefille, E., Breitzke, H., Debouttière, P.-J., Philippot, K.,

Poteau, R., Buntkowsky, G., Chaudret, B., Phys. Chem. Chem. Phys. 15, (2013),

17383-17394

(5) Gutmann, T., del Rosal, I., Chaudret, B., Poteau, R., Limbach, H.-H.,

Buntkowsky, G., Chem. Phys. Chem. 14, (2013), 3026-3033

(6) Rafter, E., Gutmann, T., Löw, F., Buntkowsky, G., Philippot, K., Chaudret, B.,

van Leeuwen, P. W. N. M., Catal. Sci. Technol. 3, (2013), 595-599


18

Advanced Solid State NMR Spectroscopy for Structural

Characterization of Supported Catalysts

Olga B.Lapina1,2

, Alexander A.Shubin1,2

1 Boreskov Institute of Catalysis, pr. Lavrentieva, 5, 630090, Novosibirsk, Russia

2 Novosibirsk State University, Pirogova, 2, 630090, Novosibirsk, Russia


The majority of the industrial catalysts are high-surface area solids on to which an

active component is dispersed in the form of very small particles. Catalyst performance

is sensitive to particle size since the surface structure and electronic properties can vary

greatly with the size range. The importance of small particles to the performance of

catalysts has stimulated extensive efforts to develop tools for their characterization. In

this presentation we are going to demonstrate the advanced solid state nuclear magnetic

resonance spectroscopy (SSNMR) for the characterization of supported oxide catalysts.

The following problems will be considered:

- dispersion of active sites: using high speed 1H MAS NMR it is possible to get

information about surface OH groups and their interaction with the supported active

component, thus to get information about the dispersion of active component;

- the structure of active sites: often active sites appear to be quadrupole nuclei (51

V, 93

Nb, 27

Al, 95

Mo, 7Li,

11B etc.), therefore the possibilities of modern multinuclear

SSNMR for quadrupole nuclei will be discussed. Special attention will be given to

applications of modern solid-state NMR methods, including very high magnetic

field (up to 21 Tesla) measurements, very fast magic angle spinning (MAS) up to 70

kHz speed of rotation, and specialized pulse techniques such as SATRAS, MASSA,

MQMAS, and CPMAS. Based on NMR data, several types of supported surface

domains could be revealed, the structure of these sites could be suggested using

known experimental correlations. To verify experimental model quantum chemical

calculations (DFT cluster and periodic GIPAW-DFT) are very useful to perform.

These approaches will be demonstrated on the example of supported binary

M1Ox/M2Ox and multilayered M3Ox/M1Ox/M2Ox catalysts (M1-3 = Si, Al, Ti, V, Nb).

Acknowledgement

This work has been supported in part by RFBR (13-03-00482) and by MES. The

Siberian Supercomputer Centre (Novosirirsk, Russia, http://www2.sscc.ru) is

acknowledged for granting access to its computational facilities (integration grant no.

130).


http://www2.sscc.ru/

19

Spin resonance of electrons localized in Ge/Si quantum dot

nanoheterostructures

Anatoly V. Dvurechenskii

Institute of Semiconductor Physics, Siberian Branch of Russian Academy of Science,

Novosibirsk State University. 630090 Novosibirsk, Russian Federation.


Electron spins in quantum dots are a promising object for the implementation of

quantum computation ideas and spintronics devices. One of the main requirements to

select materials for quantum computation is the spin coherence time. For information

exchange in quantum calculations the electronic states should be coupled usually by

exchange interaction. Quantum calculations need selective access to individual qubits

for implementation of one-qubit and two-qubit operations. There are many ideas to

realize access to individual qubits based on magnetic field, coherent light, and electric

field. One of the ability is to distinguish electrons by g-factor value. And qubit array

should be large enough for parallel computing. Many these requirements hold true in

silicon based quantum dot nanoheterostructure grown by molecular beam epitaxy. The

strain-induced potential wells in Si around Ge dots provide electron localization. The

weak spin orbit coupling in Si and existence of developed technology to reduce none

zero magnetic moment isotopes make provision for long decoherence time of electron

spin in Si. The present report aimed to review results on spin dynamics in array of Ge/Si

quantum dot nanoheterostructure. The main items of the talk are following:

• Electronic and atomic configuration of Ge quantum dot in Si.

• Electron localization in double quantum dot molecules grown with effect of

vertical alignment of nanocrystal nucleation. g-factor engineering.

• Spin relaxation in ordered quantum dot array Ge/Si structures by growth on

strained heterophase and pit-patterned substrates.


mailto:[email protected]

20

EPR in Solar Cell Research

Jan Behrends

Berlin Joint EPR Lab, Fachbereich Physik, Freie Universität Berlin,

Arnimallee 14, D-14195 Berlin, Germany


Although the electron spin does not play a central role in the operation of most

solar cells, it can provide valuable insight into charge transport and recombination

processes in these devices. Due to the fact that defects and impurities in semiconductors

are often paramagnetic or can be made paramagnetic (e.g. by illumination), EPR is the

method of choice to reveal quantitative as well as structural information. However, the

defect concentration in fully processed solar cells is often too low to be detectable by

EPR. The sensitivity limitation can be overcome by applying electrically detected

magnetic resonance (EDMR) spectroscopy. This technique measures changes in the

electrical conductivity of a semiconductor arising from manipulation of spin-dependent

transition rates that involve paramagnetic states. In this way we establish a connection

between microscopic transport and recombination pathways and the electrical

conductivity as an important macroscopic observable.

After a general introduction into the EDMR technique, its application to thin-film

silicon solar cells and their analogues based on organic semiconductors will be

presented. Besides discussing the impact of spin-dependent processes on charge

transport in solar cells, we will address the differences and similarities between radical

pairs in biological systems and spin pairs in organic and inorganic semiconductor

devices. In particular, we will outline how time-resolved EPR techniques, which are

commonly employed to investigate the role of radical pairs in biological processes, may

help to understand the kinetics of weakly-coupled polaron pairs created by

photogeneration and subsequent charge transfer at polymer/fullerene interfaces.


21

Spin-Orbit-Coupling Based Spin Chemistry

Ulrich E. Steiner

Department of Chemistry, University of Konstanz, D-78457 Konstanz, Germany


In spin chemistry, the role of spin-orbit coupling is manifested in two types of

effects: (i) the induction of intersystem crossing (ISC) processes between molecular

singlet and triplet states and (ii) the stationary entanglement of different spin-orbit states

in radicals or in general Kramers doublet species. In both cases, the resulting effects are

anisotropic.

In case (i), this means that ISC processes are selective for the population and

depopulation of triplet substates, which gives rise to electron spin polarization (CIDEP)

of the triplets and of the radicals, eventually formed from such triplets. Only under

conditions of triplet depopulation by ISC, magnetic field effects on the yield of radical

products may be observed (d-type triplet mechanism)[1].

In case (ii), the spin-orbit coupling effects are manifested as anisotropic g-tensors

of radicals with components that may significantly deviate from the free electron value

ge. Kinetic consequences are (a) enhanced spin-relaxation due (a1) to the modulation of

Zeeman interaction by rotational diffusion and (a2) to spin-rotational interaction, a

mechanism explicable in terms of adiabatic rotation of effective spin (ARES)[2,3],

furthermore (b) coherent coupling of S and T substates of radical pairs by the so-called

g- or Zeeman mechanism. Systems in which such effects of type (ii) are particularly

pronounced have been studied involve transition metal complexes of Ru[4] and Fe[5]

and the small inorganic radical NO[6].

The theoretical principles of the various spin-orbit coupling effects will be

presented and possible applications illustrated by experimental examples from the work

of the author.

References

(1) Katsuki, A.; Kobori, Y.; Tero-Kubota, S.; Milikisyants, S.; Paul, H.; Steiner, U.

E. Mol. Phys. 2002, 100, 1245.

(2) Steiner, U. E.; Serebrennikov, Y. A. J. Chem. Phys. 1994, 100, 7503.

(3) Serebrennikov, Y. A.; Steiner, U. E. J. Chem. Phys. 1994, 100, 7508.

(4) Bürßner, D.; Wolff, H. J.; Steiner, U. E. Angew. Chem. Int. Ed. 1994, 33, 1772.

(5) Gilch, P.; Pöllinger-Dammer, F.; Musewald, C.; Michel-Beyerle, M. E.; Steiner,

U. E. Science 1998, 281, 982

(6) Karogodina, T. Y.; Dranov, I. G.; Sergeeva, S. V.; Stass, D. V.; Steiner, U. E.

Chem. Phys. Chem. 2011, 12, 1714

.


22

Magnetoreception of Molecular Systems and Spin Selective

Chemical Reactions

Kiminori Maeda1)

, Paul Liddel2)

, Devens Gust2)

, and P. J. Hore3)

1)Department of Chemistry, Graduate School of Science and Engineering, Saitama

University, Saitama 338-8570, Japan.

2)Department of Chemistry and Biochemistry, Arizona State University, Tempe, Arizona,

85287-1604 USA

3)Department of Chemistry, University of Oxford, Physical and Theoretical Chemistry

Laboratory, Oxford, United Kingdom


Many experimental results of magnetic field effects (MFEs) on animal behaviour

suggested the photochemical reaction of blue light receptor proteins as the molecular

magneto reception mechanisms. Since then we have been seeing radical pair (RP)

mechanism in a new view point. Now, let us discuss the optimum conditions of RPs

for the high sensitivity to weak magnetic fields.

The coherent electron-nuclear spin motion of RP is an essential factor for the

sensitivity to extremely low magnetic field. Indeed, the low field effect (LFE) is very

sensitive to electron spin relaxation or dephasing. Since Kominis showed the doubt on

the conventional Haberkorn superoperator[1] from the quantum Zeno approach [2], the

theoretical debates about the spin dephasing accompanying with the spin selective

chemical reaction has continued. Some discussion was developed for supporting the

Haberkorn superoperators[3-5] and an alternative superoperator based on the theory of

quantum measurements was proposed by Jones et al.[6] (Jones superoperator).

Afterward, the relationship between Jones and Haberkorn superoperators was discussed

by various approaches [7-8]. However, the clear experimental test that discriminates

those two mechanisms has not been presented.

We present here the first experimental attempt to discriminate between Haberkorn

and Jones operators[9]. Pulse electron paramagnetic resonance (EPR) spectroscopy was

used to investigate in the radical pair of a carotenoid-porphyrinfullerene molecular

triad. The rate of transverse relaxation of the fullerene radical in the triad was found to

be inconsistent with the quantum measurement description (Jones) of the spin-selective

kinetics, and in accord with the conventional model (Haberkorn) combined with spin-

dephasing caused by rotational modulation of the anisotropic g-tensor of the fullerene

radical. References [1] R. Haberkorn, Mol. Phys. 32, 1491 (1976). [2] I. K. Kominis, Phys. Rev. E, 81, 029901 (2010): 83, 56118 (2011): 86, 026111

(2012). [3] P. A. Purtov, Chem. Phys. Lett. 496, 335 (2010). [4] A. I. Shushin, J. Chem. Phys. 133, 044505 (2010). [5] K. L. Ivanov, M. V. Petrova, N. N. Lukzen, K. Maeda, J. Phys. Chem. A,114, 9447

(2010). [6] J. A. Jones, P. J. Hore, Chem. Phys. Lett. 488, 90 (2010). [7] J. A. Jones, K. Maeda, and P. J. Hore, Chem. Phys. Lett. 507, 269 (2011). [8] M. Tiersch, U. E. Steiner, S. Popescu, H. J. Briegel, J. Phys. Chem. A,116, 4020

(2012). [9] K. Maeda, P. Liddell, D. Gust, P. J. Hore, J. Chem. Phys. 139, 234309 (2013)


23

The role of level-anti-crossings in spin hyperpolarization

Hans-Martin Vieth

Freie Universität Berlin, Institut für Experimentalphysik, Arnimallee14, 14195, Berlin,

Germany


The use of nuclear spin hyperpolarization is a successful strategy for increasing

the sensitivity of NMR in spectroscopy and imaging. Signal enhancements can be as

large as 3 to 4 orders of magnitude. In hyperpolarization experiments, usually the high

spin order of electronic spin systems or spin isomers is transferred to nuclei; moreover,

it is often desirable to transfer such initial polarization to other target nuclei of choice,

either protons or insensitive nuclei such as 13

C and 15

N. This situation arises in

hyperpolarization techniques such as Optical Nuclear Polarization (ONP), Chemically

Induced Dynamic Nuclear Polarization (CIDNP), Para-Hydrogen Induced Polarization

(PHIP), and the related Signal Amplification By Reversible Exchange (SABRE). Here

we give a tutorial introduction into polarization transfer mechanisms, in particular

focusing on the role of Level Anti-Crossings (LACs) therein.

So-called “spontaneous” polarization transfer may occur both at low and high

magnetic fields. Also, transfer of spin polarization can be accomplished by using

especially designed radio-frequency pulse sequences. It is now clear that at low field

spontaneous polarization transfer is primarily due to coherent spin-state mixing under

strong coupling conditions. However, thus far the important role of LACs in this

process has not received much attention. At high magnetic field, polarization may be

transferred by cross-relaxation effects. Another promising high-field technique is to

generate the strong coupling condition by spin locking using strong radio-frequency

fields. Here, an analysis of polarization transfer in terms of LACs in the rotating frame

is very useful to predict which spin orders are transferred depending on the strength and

frequency of the B1 field. Finally, we will examine the role of strong coupling and

LACs in magnetic-field dependent nuclear spin relaxation and the related topic of long-

lived spin-states.


24

Time resolved and field dependent CIDNP

Alexandra V.Yurkovskaya and Olga B.Morozova

International Tomography Center, Institutskaya 3a, 630090, Novosibirsk, Russia


Chemically induced dynamic nuclear polarization (CIDNP) is a useful tool for

studying elusive radical pairs, which are often beyond the reach of EPR spectroscopy

because of their short lifetimes and low stationary concentration. Nonetheless, spin

dynamics in transient RPs can produce significant CIDNP effects, which are stored in

the diamagnetic reaction products for the time periods equal to the nuclear T1-relaxation

times and can be studied by NMR spectroscopy. We have recently shown that in many

cases CIDNP formed after geminate recombination of RPs is directly proportional to

HFCs. This enables determination of relative HFC constants in RPs. However, when

one of the RP partners is a radical with precisely known HFC constants this method

allows one to obtain the absolute values of HFC constants of the other radical. Thus,

CIDNP gives an NMR way to obtain EPR parameters and enables investigating kinetics

of radical reactions in room-temperature solutions. At the same time, the analysis of

CIDNP is often more complicated than that in EPR and requires modeling of spin

evolution in RPs. A way to obtain the EPR parameters is measuring CIDNP dependence

on the external magnetic field strength; theoretical modeling of such field dependences

potentially allows one to obtain EPR parameters, in particular, hyperfine couplings

(HFCs) in RPs, the difference, Δg , in the electronic g-factors of the RP partners and

electronic exchange interaction. However, analysis of the CIDNP field dependence is

not as straightforward as it was previously believed. This is because at low magnetic

field spin dynamics in RPs is not the sole factor, which affects the observed CIDNP.

Coherent polarization re-distribution among scalar coupled spins creates problems in

interpreting CIDNP at low fields by transferring spin hyperpolarization. .


25

The study of practically important radical processes by spin

chemistry methods.

Tatyana V. Leshina

Voevodsky Institute of Chemical Kinetics and Combustion SB RAS, Institutskaya str., 3,

630090, Novosibirsk, Russia


The role of paramagnetic particles (ions and free radicals, singlet oxygen) in

chemical and biological processes is difficult to overestimate. Radical reactions that are

known to occur under mild conditions (room temperature, normal pressure) are

increasingly used for the organic synthesis. On the other hand growing attention paid to

the radical species involved in biological processes. Since free radicals and toxic

oxygen species are, according to modern concepts, the cause of many diseases,

medications with antioxidant properties are developed. All this makes studies of radical

transformations in organic and biological processes, as well as their role in the drugs

action high demand. One of the most powerful and modern methods of research into the

mechanisms of processes involving radical species are spin chemistry techniques. Spin

chemistry is a branch of physical chemistry that studies the effects of nuclear and

electron spins on the rates of radical chemical reactions. Two basic methods of spin

chemistry are chemically-induced dynamic nuclear polarization (CIDNP) and the

magnetic field effect. The latter studies the result of an external magnetic field action on

the rate and often also the direction of radical reactions. The basis of these phenomena

is the dependence of the spin evolution of the radical pair (RP) on the interaction of the

nuclear spins with the spins of unpaired electrons. Because of the differences in the RP

recombination rates for α and β orientations of the nuclear spins in the NMR spectra of

diamagnetic products, recorded during the reaction, the signals signs and intensities

differ from those of the equilibrium (Boltzmann) spectra. This is CIDNP effects

analysis of which allows high precision identification of free radicals involved in the

reaction. The same results can be obtained by analysis of the dependence of radical

reaction rate on the strength of the external magnetic field. This report discusses

examples of using spin chemistry techniques to determine the elementary stages of

enzymatic oxidation, the mechanisms of action of several drugs, and other important

practical processes.


26

Application of NMR in Medical Research

Nikolay E. Polyakov

Institute of chemical kinetics and combustion, Institutskaya 3, 630090, Novosibirsk, Russia


Nuclear magnetic resonance (NMR) spectroscopy is a powerful scientific

instrument which allows to shed light on molecular structure, but its greatest potential in

medical research probably lies in the information that it can reveal about molecular

interactions at the atomic level. NMR parameters, such as the chemical shift, are highly

sensitive to the exact environment of the atom, and therefore yield information about the

binding of small molecule with a target proteins or nucleic acids. Moreover NMR

technique allows to determine what parts of drug molecule are interacting with the

receptor, and to which part of the macromolecular target the drug molecule is bound.

Various NMR techniques, such as the saturation transfer, NMR relaxation

measurements (both T1 and T2), are sensitive to the overall molecular motion of organic

molecule in solution, which is very different for free and bound ligands. These simple

approaches can be used to elucidate the structure and stability of various drug delivery

systems, to identify potential ligands binding to the specific target, or to measure the

influence of various chemical compounds on the physical and functional properties of

cell membranes.

The important area of modern medical research is the investigation the

mechanisms of drug activity on molecular level, in particular, elucidation the role of

electron transfer and free radicals in drugs activity and toxicity. Some NMR

applications, for example, NMR based CIDNP technique (chemically induced dynamic

nuclear polarization), allow to determine the structure of free radical intermediates of

the drugs and their transformation into final or intermediate products by investigation

model processes in solution.

These possibilities of NMR application in medical research will be illustrated by

some recent results obtained in the Laboratory of magnetic phenomena of the Institute

of chemical kinetics and combustion (Novosibirsk).


27

EPR discovery and identification of dinitrosyl iron complexes

with thiol-containing ligands in living systems

Anatoly F. Vanin

Semenov Institute of Chemical Physics Russian Academy, Moscow, Kosygin Str.4, 119991, Russia

E-mail: [email protected] or [email protected]

EPR discovery and identification of paramagnetic mononuclear dinitrosyl iron complexes (M-DNIC) with thiol-containing (RS) ligands { formula [(RS)2Fe(NO)2]}in biological systems will be considered. The complexes were discovered by our group in the 1960

th due their characteristic EPR signal at g =2.04, g = 2.014, gav.=2.03 (2.03

signal) at first, in dry yeast cells and then in animal tissues. High shift of the g-factor values from pure spin value (g=2.0024), disappearance of 2.03 signal in yeast preparation at 80-90

0C as well as safe-keeping anisotropic shape of the signal when the

registration temperature was increased from 77K to ambient one pointed, firstly, to non-free organic nature of the paramagnetic centers responsible for the 2.03 signal, and, secondly, to these center binding with protein molecules. The identity of these centers was recognized when it was demonstrated that the shape and EPR spectroscopic parameters of 2.03 signal and EPR signals of low-molecular DNIC with cysteine or glutathione in a frozen solution were similar. Subsequent studies confirmed that the paramagnetic species giving 2.03 signal in cells and tissues are really protein-bound DNIC or DNIC with low molecular endogenous thiol-containing ligands. The properties of electronic structures of the latter underlying their ability to act as NO and NO

+

donors will be also discussed in my report. From our point of view this ability can be explained only from the paradigm of the model of the [Fe

+(NO

+)2]

+ core ([Fe(NO)2]

7

according to the Enemark-Feltham classification). Similarly, the {[(RS)2Fe(NO)2]+}

structure describing the distribution of unpaired electron density in M-DNIC corresponds to the low-spin (S=1/2) state with a d

7 electron configuration of the iron

atom and predominant localization of the unpaired electron on MO(dz2) and the square-plane spatial structure of M-DNIC. The chemical equilibrium characteristic of Fe

+(NO

+)2 fragment and its constituents {Fe

+(NO

+)2 Fe

2+ + NO + NO

+} ensures NO

and NO+ generation by the complexes. EPR and optical studies of M-DNIC as well

diamagnetic binuclear DNIC { formula [(RS)2Fe2(NO)4]} demonstrating NO and NO+

release from the complexes will be presented in the report.

Our opponents who studied M- and B-DNIC in crystalline state proposed that the distribution of unpaired electron density in M-DNIC is described as {[RS

-

2)Fe3+

(NO-)2]

-}. Spin-pairing of electron density on iron (Fe

3+, S=5/2) and two nitroxyl

ligands (NO-, S=1) resulted in the sum spin of the complexes S=1/2 with a d

9 electron

configuration of the iron atom ([Fe(NO)2]9 according to the Enemark-Feltham

classification). The complex in the crystalline state is characterized with tetrahedron structure. The investigators propose that electronic and spatial structures of the complexes do not change during the process of complex dissolving. In the frame of this model, it is hardly to explain the ability of DNICs with thiolate ligands to act as NO and NO

+ donors.

Miscellaneous effects of M- and B-DNIC with thiol-containing ligands as NO and NO

+ donors

on various physiological and biochemical processes will be considered.

The complexes hold considerable promise as a base in the design of a radically new generation of drugs with a broad spectrum of therapeutic activities.



28

ORAL PRESENTATIONS

OF YOUNG SCIENTISTS

29

Oral presentation of young scientists, September 9, 15:00-19:30

FMR study of Cr1/3NbS2 helical magnet

Fedor B. Mushenok Institute of Problems of Chemical Physics,

Ak. Semenova st., 1, 142432, Chernogolovka, Russia


Incommensurate magnetic structures are intrigue objects of the solid state

physics. The pressing problem is the influence of the magnetic anisotropy on a magnetic

phase diagram and a spectrum of the spin excitations. The aim of the present work is to

establish how magnetocrystalline anisotropy influents on spin excitation in the chiral

“easy-plane” helimagnet Cr1/3NbS2.

High frequency spin excitations were studied by ferromagnetic resonance (FMR)

method [1]. At low temperature (T < 50 K) FMR spectra consist of two lines with

different temperature dependences of resonance fields Hres (Fig. 1). The line I with

“usual” ferromagnetic temperature dependence of resonance field corresponds to

homogeneous (q = 0) magnetization precession in a helical phase. The resonance field

of the line I is determined by uniaxial magnetocrystalline anisotropy K2. The line II with

“abnormal” temperature dependence of resonance field corresponds to the Goldstone

mode with a wave factor q = ±Q (Q is wave vector of the modulated magnetic

structure). The finite value of the Goldstone mode energy q = ±Q is due to

magnetocrystalline anisotropy in basal ab plane. Unusual temperature dependence of

the resonance field is explained by decreasing of anisotropy constant K6 with

temperature increasing.

Figure 1. Temperature dependences of resonance fields of lines I and II for

Cr1/3NbS2 single crystal, H ┴ c (┴ Q). Critical field of transition to ferromagnetic state

is shown by dashed line. FMR spectra at T = 5 K is shown on inset.

The work was supported by grant of President of Russia MK-1474.2014.

[1] F.B. Mushenok, J.Eur. Phys. Journ. B, 86 (2013) 1-4.

30


Possibilities of EPR diagnostics for monitoring the

sportsmen’s state of health

Chushnikov A. I., Ibragimova M. I., Petukhov V. Yu., Cherepnev G. V.

Kazan E. K. Zavoisky Physical -Technical Institute, Sibirsky Tract, 10/7, 420029, Kazan, Russia, State

Autonomous Healthcare Institution Republican Clinical Hospital №2 Heath Ministry of Tatarstan Republic

Email: [email protected]

The work is devoted to study the possibilities of EPR application for monitoring

the professional sportsmen’s health state. Measurements of ~ 120 serum blood samples

collected from players of continental hockey league teams were carried out using

Bruker EMXplus spectrometer at a frequency ~ 9.5 GHz in the temperature range T=5-

80K and haematological and biochemical laboratory tests as well. The control group

included healthy individuals and patients with different diseases.

The main peculiarities of sportsmen EPR spectra are the appearance of the

additional absorption lines in comparison with norm. In particular, in the 20 spectra

measured at T=77 K the significant portion of new signals have the spectroscopic

parameters close to signals from the oxygenic active isolated form of cytochrome-c-

oxidases. Moreover, the anisotropic signals with g1 2.02; g2 1.94 and g3 1.86

registered in some spectra pointed to the sulfur-iron centers. In experiments carried out

at T=5K other additional lines with g-factors ~ 11, 8.6 and 5.85 were detected. In

accordance with literature data they correspond to lines from cytochrome-c-oxidases.

Intensity of these lines decreases with temperature and become almost zero at T=40K

(in agreement with literature review).

There was nearly linear correlation between the concentration of Fe3+

in transfferin

(Fe3+

-Tf) obtained from the EPR spectra and the serum iron concentration measured by

absorption photometry both for sportsmen and controls. The Spirmen correlation

coefficient for Fe3+

-Tf and serum iron values was of 0.84 in sportsmen versus r=0.97 in

controls. The possible reasons of lower correlation between Fe3+

-Tf and serum iron

concentration for sportsmen in comparison with controls are discussed.

Application of the EPR method can be useful for monitoring of sportsmen health

state so far as the routine biochemical and haematological tests are insufficient to

discover, for example, such enzymes as cytochrome-c-oxidase.

The work is supported by RFFR Grant #13-02-97065.


31


Highly efficient exciplex formation in case of X-ray

irradiation of non-polar solutions

Anatoly R. Melnikov1,2

, Evgeny V. Kalneus1, Valeri V. Korolev

1,

Igor G. Dranov1, Alexander I. Kruppa

1, Dmitri V. Stass

1,2

1 Institute of Chemical Kinetics and Combustion SB RAS, 3, Institutskaya Str., 630090

Novosibirsk, Russian Federation 2 Novosibirsk State University, 2, Pirogova Str., 630090 Novosibirsk, Russian Federation


This work reports the spectra of photo- and radiation-generated luminescence from

several donor-acceptor systems typical for radiation spin chemistry, i.e., alkane

solutions of naphthalene/N,N-dimethylaniline (DMA), p-terphenyl/DMA, and other.

One component of the system (DMA, positive charge acceptor) was held constant, and

as the other component (electron acceptor, luminophore) were chosen molecules with

widely varying lifetimes of the electronically excited state τf, from about 100 ns to about

1 ns and to about 10 ps. In this work we also studied the sensitivity of the obtained

emission spectra to external static magnetic field, and obtained the close to maximally

possible under these experimental conditions magnetic field effect (up to 20%) in

exciplex emission band for the system diphenylacetylene/DMA in n-dodecane.

300 350 400 450 500 550 600

0

5

10

15

20

0 mT

20 mT

N

I, a

.u.

, nm

A + D

A

D

= A

= D

hADDADA alkanerayX *, )()(

Figure 1. X-irradiation of alkane solution of DMA and diphenylacetylene produces exciplex from

luminophore with τf equals to 8 ps, and yields magnetic field effect of 20% in exciplex emission band.

The work was supported by the Council for Grants of the President of the Russian

Federation for Support of Leading Scientific Schools (project no. NSh 2272.2012.3) and

the Russian Foundation for Basic Research (project no. 13–03–00771).

32


Exploiting Level Anti-Crossings in the rotating frame for

transferring spin hyperpolarization

Andrey N. Pravdivtsev,a,b

Alexandra V. Yurkovskaya,a,b

Nikita N. Lukzen,a,b

Hans-Martin Vieth,c Mikhail S. Panov,

a,b Konstantin L. Ivanov

a,b

a International Tomography Center, Siberian Branch of the Russian Academy of Science,

Institutskaya 3a, Novosibirsk, 630090, Russia

b Novosibirsk State University, Pirogova 2, Novosibirsk, 630090, Russia

c Institut für Experimental Physik, Freie Universität Berlin, Arnimallee 14, Berlin, 14195,

Germany


A method of transferring hyperpolarization among scalar-coupled nuclear spins is

proposed, which is based on spin mixing at energy Level Anti-Crossing (LAC) regions.

To fulfill LAC conditions a resonant RF-field was applied with properly set frequency

and amplitude. In this situation LACs occur between the nuclear spin levels in the

rotating doubly tilted reference frame. The validity of the approach is demonstrated by

taking as an example the transfer of para-hydrogen induced polarization in a symmetric

molecule, whose coupled spin network can be modeled as a four-spin AA′MM′-system

with two pairs of ‘isochronous’ spins. For this spin system LAC positions have been

identified; rules for the sign of spin polarization have been established. The dependence

of the polarization transfer efficiency on the RF-field parameters and on the time profile

of switching off the RF-field has been studied in detail; experimental results are in

excellent agreement with the theory developed. In general, exploiting LACs in the

rotating doubly tilted frame is a powerful tool for manipulating hyperpolarization in

multispin systems.

The research was financially supported by the Russian Fund for Basic Research

(projects No. 13-03-00437, 14-03-00397) and grant of the President of Russian

Federation MD-3279.2014.2.

33


Experimental and Theoretical NMR Analysis of

Paramagnetic M(acac)3 (M = Cr, Mn) Coordination

Compounds

Kirill Levin, Scott Kroeker

Department of Chemistry, University of Manitoba, Winnipeg, Canada, R3T 2N2


Solid state nuclear magnetic resonance (NMR) spectroscopy is a widely used

technique for the characterization of materials. The versatility of NMR spectroscopy

stems from its sensitivity to variations in local structural environments. However, a

recognized drawback of NMR is its limited applicability to paramagnetic systems such

as organic radicals and many organometallic complexes, where the presence of unpaired

electrons introduces an additional layer of difficulty to spectral acquisition and

interpretation. Recent advances in instrumentation have reopened the investigation of

paramagnetic solids.

We are studying a series of isostructural metal acetylacetonate complexes to better

understand the experimental and analytical particularities of such systems. 13

C magic-

angle spinning NMR of M(acac)3 (M = Cr, Mn, Co, Al) reveals interesting spectral

differences which are related to the electronic structure and bonding, thereby providing

valuable clues about optimizing acquisition and inferring electronic distributions. For

example, Cr(acac)3 and Mn(acac)3 produce dramatically different NMR spectra due to

the presence of t2g3 and t2g

3eg

1 electronic configurations, respectively.

Density functional theory provides detailed electron distribution maps of the

complexes which are used to assign crystallographic sites and delineate spin-transfer

mechanisms. Molecular orbital theory renders the analysis more intuitive and facilitates

extensions to other materials. The use of simple model coordination compounds is

intended to provide the foundation for a more general approach to utilizing unpaired

spin density as a new tool for structural analysis of paramagnetic materials.

Figure 1. Spin density distribution through the molecular orbital for a ligand of

Cr(acac)3

34


The EPR Study Of Light-Induced Thermally Inaccessible

Spin State In Copper-Nitroxide Based Molecular Magnet

Irina Yu. Barskaya,a*

Evgeny V. Tretyakov,a Renad Z. Sagdeev,

a Victor I.

Ovcharenko,a Elena G. Bagryanskaya,

a,b Kseniya Yu. Maryunina,

c Takeji Takui,

d,e

Kazunobu Sato,d.e

Matvey V. Fedina

aInternational Tomography Center SB RAS, Institutskaya str. 3a, 630090, Novosibirsk, Russia;

bNovosibirsk Institute of Organic Chemistry SB RAS, Pr. Lavrentjeva 16, 630090, Novosibirsk, Russia;

cDepartment of Chemistry, Graduate School of Science, Hiroshima University, Japan;

dGraduate School of Science, Osaka City University, Osaka 558-8585, Japan;

eFIRST-Quantum Information Processing Project, JSPS, Tokyo 101-8430, Japan


Polymer-chain molecular magnets formed by Cu(hfac)2 and various nitroxide

radicals usually demonstrate the thermal transition between two different spin states:

weakly-coupled spin state (WS) with exchange interaction J between nitroxide and

copper spins smaller than thermal energy (J~1-10 cm-1

), and strongly-coupled spin state

(SS), where exchange interaction is higher than thermal energy (J~100-200 cm-1

). As a

rule, WS state is observed at high temperatures, whereas SS state is formed at lower

temperatures. However, a few compounds of this family could not be switched to WS

state within the temperature range of their stability (~2-350 K). Therefore, up to now the

existence of the excited spin state in such type of compounds was not realized and

evidenced. In this work we report the first example of photoswitching to the thermally-

inaccessible spin state of Cu(hfac)2Li-Pr

by visible light at cryogenic temperatures. One

of the main problems in photo-investigation of such compounds is their high optical

density. To overcome this, we developed specific method of synthesis performed in

PVC matrix and yielding thin, flexible film exhibiting photoswitching efficiency close

to 100%. Upon generation of the excited spin state spin state in Cu(hfac)2Li-Pr

by laser

illumination, we could detect and study it using continuous wave Q-band (34 GHz) and

time-resolved W-band (94 GHz) EPR. It was found that the electronic structure and

photoswitching properties of excited spin state in Cu(hfac)2Li-Pr

are very similar to its

thoroughly investigated sister compound Cu(hfac)2LPr

that does undergo thermal

transition at ~150 K. Similar to thermally switchable compounds of this family, the

relaxation rate in Cu(hfac)2Li-Pr

has a self-decelerating character due to the broad

distribution of activation energies. By analyzing the temperature dependence of

relaxation rates and the conversion depths we succeeded in estimation of the values of

energy barriers and distribution widths for both compounds. Acknowledgements: This

work was supported by the Russian Foundation for Basic Research (No. 14-03-00224)

and the RF President's Grant (МК-3241.2014.3, MD-276.2014.3).

[1] I. Yu. Barskaya, et. al., JACS, 2014, 136, 10132-10138.

35


Proton transfer process in C-H···X hydrogen bonds

Elena Yu. Tupikina, Gleb S. Denisov, Peter M. Tolstoy

Institute of Physics, Saint-Petersburg State University, Ulyanovskaya str., 3, 198504, Saint-

Petersburg, Russia;


Hydrogen bonds involving CH group are extremely important for many biological

systems, inasmuch as plays crucial role in structure stabilization and crystal packing.

For example, formation of a relatively weak hydrogen bond between OH-group of

ibuprofen and one of carbon atoms of tyrosine most likely is the basis of medical action

mechanism of ibuprofen [1]. Furthermore, formation of CH···X bond is also a primary

step of CH proton transfer – the most ubiquitous reaction in biochemical synthesis [2].

In this work we focused on proton transfer process between CH-acids (e.g. 1,1-

dinitroethane, trinitromethane) and different proton acceptors (e.g. acetone, pyridine,

2,4,6-collidine, fluoride anion). In such systems formation of relatively strong hydrogen

bonded complexes and even zwitterionic complexes is possible. Our main goal was to

investigate processes of hydrogen bond formation and proton transfer for complexes

with CH-acids, which schematically depicted for 1,1-dinitroethane and 2,4,6-collidine

system at figure 1. Using ab initio calculations and different experimental techniques

(NMR spectroscopy, X-Ray) we find some interesting features and correlations between

geometric and NMR parameters.

Figure 1. Scheme of hydrogen bond formation and proton transfer process for 1,1-

dinitroethane and 2,4,6-collidine complex.

[1] J. A. Kowalska-Baron1, M. Brychtova, I. Petrovic, I. Passos Sene, P.

Quinones, J. Sogorkova // Biotechnol Food Sci, , v. 75, № 2, p. 15, (2011).

[2] S. Scheiner // Curr. Org. Chem., v. 14, p. 106, (2010).

36


I nvestigation of some acetophenone derivatives in solution

by NMR

A.M.Maharramov, M.R.Bayramov, Y.V.Mamedova, A.E.Huseynzada,

I.G.Mamedov

Baku State University, Azerbaijan, Z.Khalilov-23, e-mail: [email protected]

Nuclear magnetic resonance (NMR) spectroscopy plays an important role in

studying various interactions in solution including hydrogen bond formation. NMR has

become an important method to evaluate the kinetics of reactions at equilibrium over a

very large dynamic range, its results have theoretical and practical significance.

Oxime compounds are used as antidotes for nerve agents, amides are widespread

in nature and technology as structural materials. Thiosemicarbazones also are used in

medicine, especially as anticancer chemotherapeutic agents, in the treatment of

tuberculosis. Because of the presence of different functionality in thiosemicarbazones

these compounds confer biological activities, such as cytotoxic and antimalarial. The

behavior of such molecules in solution as well as the presence or absence of molecular

association and dynamic processes is of considerable theoretical and practical interest.

This concerns, particularly, the dynamic transitions in solution for the some 2-hydroxy-

5-methylacetophenone derivatives.

N

O

HOH

H3C

O

N

CH3

N S

NH2H

H

N

CH3

N S

NH2

H

Br

The results confirmed the existence of two conformers for the molecule N-(2-

hydroxy-5-methylphenyl)acetamide, two conformers for the molecule (E)-4-

bromoacetophenone thiosemicarbazone and four conformers for the molecule (E)-2-

hydroxy-5- methylacetophenone thiosemicarbazone.

37


Fluorinated homocysteine derivatives as potential molecular

probes for 19

F magnetic resonance spectroscopy and imaging:

synthesis and characterization

Alexey S. Chubarov, Makhmut M. Shakirov, Viktor I. Mamatyuk, Dmitry

G. Knorre, Tatyana S. Godovikova

Institute of Chemical Biology and Fundamental Medicine, Lavrentyev ave, 8, 630090, Novosibirsk,

Russia

Novosibirsk State University, Pirogova st., 2, 630090, Novosibirsk, Russia


One of the most perspective molecular imaging modalities is magnetic resonance

imaging (MRI). It evolves as a prominent technique because MRI is a noninvasive and

nondestructive diagnostics with high spatial resolution including 3D imaging. In

addition to 1H MRI techniques, a number of attractive contrast agents based on

19F

NMR signals are increasingly emerging. The fluorine MRI is of interest for several

following reasons. Fluorine offers a strong NMR signal magnitude as large as 1H nuclei

due high gyromagnetic ratio, high natural abundance sensitivity and a much wider

frequency range thus is ideally suited for tracking objects and monitoring reactions in

vivo. Only externally administered fluorine can be imaged by the 19

F MRI because of

the absence of background signals in a living body. Highly fluorinated compounds with

a single resonance frequency are advantageous in these applications because they

provide large signal-to-noise rations, saving the acquisition time necessary for imaging.

In this study, fluorinated homocysteine thiolactone derivatives have been

synthesized and characterized as potential in vivo 19

F NMR agents. The latest

compounds have been used for preparing a fluorine-labeled N-homocysteinylated

protein, in particular 19

F-Hcy- N-Lys-human serum albumin. The protein was

characterized by SDS-PAGE, MALDI-TOF MS, UV-vis and 19

F NMR. Albumin has

been successfully modified resulting fluorine labeled biocompatible molecular probe

with useful NMR characteristics. Given the relatively high sensitivity of 19

F NMR, it

should be possible to detect exogenously administered 19

F-labeled probe molecules.

The work was supported by RFBR № 14-04-00531, President Grant (NS-

1205.2014.4) and Integration grant of SB RAS № 60.

38


2H NMR study of the rotational dynamics of terephatalate

phenylenes in metal-organic frameworks CoMOF, NiMOF

and ZnMOF: effect of different metal centers

A.E.Khudozhitkov† , D.I.Kolokolov

†,‡ , A.G.Stepanov

†,‡ , D.N.Dybtsev

†* ,

V.A.Bolotov†*

†Novosibirsk State University, Faculty of Natural Sciences, Department of Physical Chemistry,

Pirogova Street 2, Novosibirsk 630090, Russia

‡Boreskov Institute of Catalysis, Siberian Branch of Russian Academy of Sciences, Prospekt

Akademika Lavrentieva 5, Novosibirsk 630090, Russia

*Nikolaev Institute of Inorganic Chemistry, Siberian Branch of Russian Academy of Sciences,

Prospekt Akademika Lavrentieva 3, Novosibirsk 630090, Russia

[email protected]

Metal organic framework (MOFs) materials represent a new class of hybrid crystalline

porous materials whose pore structure and chemical properties can be very diverse depending

on the chemical composition and synthesis procedure. Their unique properties allow exploiting

of MOFs in many fields such as adsorptions or separation of gases and liquids, catalysis and

others. The MOFs are composed by inorganic nodes (i.e. the metal centers) bridged together by

organic linkers.

Fragments of organic framework may be mobile and their motion is a huge source of

structural information. There are two major mechanisms influencing the rate of molecular

motions: steric and the electronic structure. On the fundamental level there exists an unresolved

problem: what contribution does each of these mechanisms make?

To investigate this question a set of materials with identical structure but different nature of

the metal center was examined. In such approach the steric component remains the same for all

materials while the electronic component is affected by different electronic structure of the

metal cation. As result, the influence of the MOF metal center variation (Co, Ni, Zn) on the

dynamics of terephthalic fragment was observed.

The phenylene dynamics investigation was performed by experimental detection of the 2H

NMR spectra line shapes at different temperatures followed by numerical simulation of the

registered spectra.


39


Influence of glycyrrhizin on cell membrane properties

Selyutina O. Yu.1,2

, Polyakov N. E.1

1Institute of Chemical Kinetics and Сombustion SB RAS, Institutskaya st.,3, 630090,

Novosibirsk, Russia

2Novosibirsk State University, Pirogova st., 2, 630090, Novosibirsk, Russia


Glycyrrhizic acid or glycyrrhizin (GA) is natural oligosaccharide contained in the

extract of licorice roots, showing a wide spectrum of biological activity. GA and its

derivatives are widely used in medicine for the treatment of asthma, eczema, dermatitis,

ulcers of the stomach and duodenum. Due to its amphiphilicity GA is capable of

forming stable complexes with various drugs and biologically important molecules,

such as cholesterol [O.Yu. Gluschenko, N.E.

Polyakov, T.V. Leshina, Appl. Magn. Res., 41

(2011) 283-294]. This, coupled with the lack of

toxicity, makes glycyrrhizic acid promising agent

for targeted drug delivery. However, for its wide

application in this field, it is necessary to establish

a mechanism as its own biological activity, as the

enhancement of the drugs activity in the presence

of GA. One way to elucidate this mechanism is

studying the effect of GA on the properties of the

cell membrane.

In this work an attempt to clarify the molecular mechanism of effect of glycyrrhizic

acid (GA) on the properties of cell membranes was made. The effects of GA on the

functional properties of the membranes of living cells have been studied for a better

understanding of the mechanism of GA activity. The effect of GA on membrane

permeability, as well as on the mobility within the membrane lipids was investigated by

NMR techniques. RBCs were selected as a model object in or study, as the most

affordable and relatively resistant to external influences, and liposomes, as a system

with the controllable composition. The significant increase in permeability of

erythrocyte membranes in presence of GA was established by means of NMR

relaxation. This fact could explain some facts of increase in drugs bioavailability in

human body.

This work was supported by grant RUC-7067-NO-12 from the U.S. Civilian

Research & Development Foundation (CRDF Global) with funding from the United

States Department of State.

Fig. 1. The structure of

glycyrrhizic acid

40


Low-field NMR Spectroscopy and Imaging Via Parahydrogen

Based Hyperpolarization: Towards catalyst-free molecular

contrast agents and MRI of industrial hydrogenation

Danila A. Barskiya, Kirill V. Kovtunov

a, Igor V. Koptyug

a, Boyd M.

Goodsonb, Aaron M. Coffey

c, Milton L. Truong

c, Eduard Y. Chekmenev

c

International Tomography Center SB RAS, Novosibirsk State University, 630090, Russia

Southern Illinois University, Carbondale, 62901, USA

Vanderbilt University, Institute of Imaging Science, Nashville, 37232-2310, USA

High-resolution proton MRI/NMR was demonstrated at 47.5 mT magnetic field

endowed by Parahydrogen-Induced Polarization and Signal Amplification by

Reversible Exchange (SABRE). Low-field (milli-Tesla) parahydrogen-enhanced

molecular imaging (i.e. imaging of dilute hyperpolarized chemicals rather than the bulk

medium) is free from limitations of high-field magnetic resonance (MR), such as B0

susceptibility at phase interfaces, and potentially enable new application of MR in vivo

(lung imaging) and for industrial processes of hydrogenation and hydrogen exchange

for visualization of reactants, intermediates and products in chemical reactors.

Figure 1. 1H MRI of SABRE hyperpolarized

(HP) molecular contrast agent (pyridine - Py).

Two orthogonal projections of non-slice

selective MRI of a) in situ SABRE detection

(HP Py, Ir-hydride and orthohydrogen) at

47.5 mT with 0.75 0.75 mm2 in-plane spatial

resolution; b) ex situ SABRE (preparation at

5.75 mT and detection at 47.5 mT) of Py with

0.125 0.125 mm2 and 7.7 s temporal

resolution.

c) Photograph of ~3 mL solution of 100 mM

Py with 7 mM Ir catalyst in a 10 mm NMR

tube with 1/16 in. OD PTFE tubing for

parahydrogen bubbling at 1 atm.

This work is supported by the RAS (5.1.1), RFBR (12-03-00403-a, 14-03-00374-a,

14-03-31239-mol-a, 14-03-93183 МСХ_а), SB RAS (60, 61), the Ministry of

Education and Science of the Russian Federation, and the Council on Grants of the

President of the Russian Federation (MK-4391.2013.3). We also thank for funding

support NIH 5R00 CA134749-03, 3R00CA134749-02S1, DoD CDMRP Breast Cancer

Program Era of Hope Award W81XWH-12-1-0159/BC112431.

41

POSTERS

Poster 1

42

Investigation of some alkenylphenol derivatives in solution

by NMR

A.M.Maharramov, M.R.Bayramov, M.M.Agayev, I.G.Mamedov

Baku State University, Azerbaijan, Z.Khalilov-23


The NMR line shape is sensitive to temperature and chemical exchange

processes. For rational design and structure properties correlations of different systems

one need to know their structure and dynamics in solution. To this end variety of NMR

methods can be helpful. The DNMR results have theoretical and practical significance

for chemistry, medicinal chemistry, biochemistry and molecular physics.

The alkenylphenols and their aminomethyl, acetyl derivatives are used at

different organic synthesis as monomer stabilizers for polymerization, corrosion

inhibitors, and antimicrobial additives to oils and fuel, etc. All these compounds contain

hydroxyl, carbonyl groups, unsaturated bonds, sulphur and nitrogen atoms. The

behavior of such molecules in solution, the presence and absence of molecular

association are of considerable theoretical and practical interest. This concerns

particularly the formation of hydrogen bonds, inter- and intramolecular interactions in

solution for the molecules of alkenylphenols, their aminomethyl, sulfide, and acetyl

derivatives.

Our investigations confirm the formation of intermolecular hydrogen bonds in

alkenylphenols and its sulfide derivatives, and of intramolecular hydrogen bonds in

aminomethyl and acetyl derivatives. In CCl4 solution of 2-allyl-6-tert-butylaminomet-

hylphenol, no hydrogen bonds are observed due to steric effect of the tertbutyl radical.

The structure and hydrogen bond energy of the received phenols have an impact on their

practical properties. In alkenylphenol derivatives, free hydroxyl groups have high

antimicrobial and antibacterial properties. For example, as a result of joint effect of

nitrogen atom, unsaturated bond and free hydroxyl group, 2-allyl-6-tert-

butylaminomethylphenol has higher antimicrobial and antibacterial properties in jet fuel

TS-1 than other obtained alkenylphenol compounds.

Poster 2

43

Supramolecular complexes of macular carotenoids with

enhanced solubility and oxidation stability.

a,b

Irina E. Apanasenko, a

Nikolay E. Polyakov, a,b

Olga Yu. Selyutina, cLyubov P.

Suntsova, cAlexander V. Dushkin,

dLowell D. Kispert,

fPreejith Vachali,

fPaul S. Bernstein.

aInstitute of Chemical Kinetics and Combustion, Novosibirsk, Russia;

bNovosibirsk State University, Novosibirsk, Russia;

cInstitute of Solid State Chemistry and

Mechanochemistry, Novosibirsk, Russia; dUniversity of Alabama, Tuscaloosa, AL, USA;

fDepartment of Ophthalmology and Visual Sciences, Moran Eye Center, University of Utah

School of Medicine, Salt Lake City, UT, USA.


Macular carotenoids play a special role in the prevention and treatment of visual diseases. These

carotenoids are not produced by the human body and must be consumed in the diet. On the other hand,

instability of carotenoids in the presence of water, oxygen and metal ions, and their high photosensitivity

restricted their practical application as components of food or medicinal formulations. The preparation of supramolecular conjugates of macular carotenoids (zeaxanthin and lutein) with a

triterpene glycoside, glycyrrhizic acid (GA), and natural polysaccharide arabinogalactan (AG) allows to

minimize the aforementioned disadvantages when carotenoids are used in food processing (colors and

antioxidant capacity) as well as for production of therapeutic formulations considering the better

solubility and stability. We present a new approach for preparation of inclusion complexes of carotenoids

with natural oligosaccharides and polysaccharides using mechanochemical technique. This technique

allowed us to prepare water soluble complexes

of a series of very low soluble drugs and

carotenoids in one step without using of any

organic solvents [1]. It was found that complexation increases the

photostability of macular carotenoids as well as

their stability towards oxidation. In particular,

the rate of carotenoid oxidation by ozone in

aqueous solution reduced by orders of

magnitude in AG and GA inclusion complexes

(Figure 1). It is known that xanthophyll

carotenoids can self-assemble in aqueous

solution to form J- and H-type aggregates. This

feature significantly changes the photo-physical

and optical properties of these carotenoids, and

has an impact on solar energy conversion and

light induced oxidative damage. H-aggregates of

carotenoids exhibit higher photostability in

aqueous solutions as compared with monomers.

It was found that GA does not affect the

photostability of xanthophyll carotenoids. However, the significant increase (5−10 times) in

photostability was detected for AG complexes of these carotenoids [2]. Moreover, the increase in

photostability was detected for both monomer and H-aggregate of xanthophylls. This means that AG can

form inclusion complexes with monomers as well as with H-aggregates of carotenoids.

Acknowledgements. This work was supported by grant RUC-7067-NO-12 from the U.S. Civilian

Research & Development Foundation (CRDF Global) with funding from the United States Department of

State, and grant DE-FG02-86ER-13465 from the U.S. Department of Energy.

[1] N.E. Polyakov, T.V. Leshina, E.S. Meteleva, A.V. Dushkin, T.A. Konovalova, and L.D.

Kispert, J. Phys. Chem. B, 113, 275-282 (2009).

[2] N.E. Polyakov, A. Magyar, L.D.Kispert, J. Phys. Chem. B; 117, 10173-10182 (2013).

Figure 1. Kinetics of lutein decay in reaction with

ozone in 25% aqueous ethanol solution in pure form

and in the inclusion complexes.


Poster 3

44

Magnetic field effects in E.coli cells in the presence of the

isotope Mg

Avdeeva E.I., Letuta U. G., Berdinsky V.L.

Orenburg University, Orenburg, Tereshkova st. 134/2, 460000


Effects of nuclear spins of magnetic isotopes 25

Mg and nn

Zn in vitro and in vivo

have proved that enzymatic electron transfer processes producing intermediate ion-

radical pairs are spin dependent processes. For example, the presence of 25

Mg (nuclear

spin I = 5/2) in active cites of some enzymes in bacterial cells E. coli accelerates growth

rate and increases their viability [1,2]. Thus such processes should be magnetic field

dependent ones and could be primary steps responsible for biological magnetoreception

in any living organisms without special magnetosensitive organs . New effects of weak

magnetic fields (0 -100 mT) were shown to be dependent on presence of magnetic 25

Mg

or nonmagnetic 24,26

Mg isotopes in E.coli cells.

1. A. L. Buchachenko, Magnetic isotope effects in chemistry and biochemistry –

New York: Nova Science Publishers, Inc. – 2009. – 152 p.

2. Shevchenko U.G, Koltover V.K., Deryabin D.G., Berdinsky V.L. Magnesium

isotope effect on enzymatic phosphorylation and growth of E. coli cells

https://docviewer.yandex.ru/r.xml?sk=yd8e32837aeb397abeeb51c43fc85bb11&url=mailto%3Aavdeevaelenaosu%40yandex.ru

Poster 4

45

Self-Organization Features of the Copper(II)

3-Amino-4-Ethoxycarbonylpyrazole Compound.

A.S. Berezin1,2

, V.A. Nadolinny1, L.G. Lavrenova

1,2

1Nikolaev Institute of Inorganic Chemistry, 630090, Novosibirsk, Russia

2Novosibirsk State University, 630090, Novosibirsk, Russia

[email protected]

Synthesis and study of compounds with the magnetically active structure are both

of the fundamental and practical interest in the electronics, medicine, etc. The

investigation results of the self-organization features by EPR, XRD, SQUID and Raman

scattering of the CuL2Br2 compound are presented.

The EPR spectrum of the initial powder sample is a single line with the g=2.155

that is independent of temperature, the line width equals 830 G at 300K. By lowering

the temperature of the sample to T = 77K, ∆H is reduced to 720 G. Simultaneously the

sample changes the color reversibly. After the heat treatment of the sample (from 77K

to 300K) the new absorption line appears in the zero magnetic fields in the EPR

spectrum. The heat treatment reiteration leads to increase of the new line intensity and

decrease of the intensity of the line with g=2.155 in the EPR spectra. The XRD data

indicate, after the heat treatment the phase change occurs in the sample, presumably,

with the formation of the strained structures. In Raman spectra, the disappearance of the

pyrazole rings vibrations is observed in the treated sample. Stabilization of the pyrazole

ring is expected to be due to the bromide forks. However, the dispersion or dissolution

of the trained sample leads to the return to its original state.

In the EPR spectra of the sample with new absorption line, the hysteresis loop is

observed, the maximum value of which is reduced with increasing the temperature. All

of this indicates the formation of the magnetic domain structure in the sample.

Moreover, this sample immediately is attracted to a magnet. So, the trained compound

exhibits ferromagnetic properties and ability to nonresonantly absorb the high frequency

energy. But the new absorption line intensity and line width increases with increasing

temperature. Such behavior is characteristic for the spin glass.

Based on the data, the two models of self-organization are proposed. First, polymer

chains of the sample are moved towards to each other such that the bromide forks

stabilize pyrazole rings, whereupon the additional exchange interaction channels arise

between the copper atoms. Second model, angles between the ligands and the Cu plane

change, as stated above the bromide forks stabilize pyrazole rings, thereby the

interaction between the copper atoms in the chain is changed. After self-organization,

the CuL2Br2 has a residual magnetization. Moreover, the self-organization occurs both

in the polycrystalline form and in the film structures during thermal or pressure training.

Poster 5

46

The effect of chemical reaction on the spin states evolution

of spin-correlated radical ion pairs

A. O. Bessmertnykh, V. I. Borovkov, V. A. Bagryansky ICKC, Institutskaya 3, 630090, Novosibirsk, Russia


A way to create an ensemble of spin-correlated radical ion pairs (RIPs) is the

ionizing irradiation of solutions. The spin evolution of the ensemble can be observed via

the fluorescence, which originates from the recombination of the RIPs. If the singlet-

triplet spin states transitions are caused by hyperfine couplings (HFCs) of the unpaired

electron spins with magnetic nuclei of the RIP partners the evolution typically appears

as oscillations (quantum beats) in the fluorescence intensity decay. Reactions between a

partner of RIP and molecules in the solution change the magnetic environment of the

unpaired electron that affects the spin evolution. Thus the quantum beats analysis is

expected to allow measuring the reaction rate with simultaneous obtaining the

spectroscopic information about the reagents involved.

The above approach was used to study reactions of positive charge transfer to

aliphatic amines in irradiated alkane solutions as well as reactions of the amine radical

cations with nitroxide radicals. To reduce complications related to taking into account

the kinetics of the geminate RIP recombination the ratio of recombination fluorescence

kinetics in nonzero and zero magnetic fields, IB(t)/I0(t), respectively was analyzed. This

method is referred as the method of time-resolved magnetic field effect (TRMFE) in

recombination fluorescence. Both solutions irradiation and fluorescence detection were

performed using the nanosecond X-ray fluorometer, developed in the ICKC SB RAS.

An emphasis has been made to

investigate the spin-selective

reactions of the positive RIP partner

with a third paramagnetic particle,

nitroxide radical (TEMPON). The

figure exemplifies the experimental

(scatter) and theoretical (lines)

TRMFE curves obtained for n-

hexane solution of

tetramethylpiperidine ([C9H19N]=3

mM) and para-terphenyl-d14 ([p-TP-

d14]=0.4 mM). At the absence of

TEMPON, the quantum beats (triangles) are mainly caused by HFC with a single

nucleus N in the RIP (C9H19N)2+

/p-TP-d14 . An addition of TEMPON causes

quenching the quantum beats (circles), which take place in the RIP subensemble which

has escaped the reaction with TEMPON. It is shown that the spin-selective reaction

with a third paramagnetic particle can be described as an additional rate of both the

phase and spin-lattice relaxation, which is proportional to the reaction rate.

Poster 6

47

The Investigation of NMR Parameters of

Heptafluoroindenyl Cation

Dmitriy S. Fadeev, Igor P. Chuykov, Victor M. Karpov, Victor I. Mamatyuk

Novosibirsk Institute of Organic Chemistry, Lavrentiev ave., 9, 630090, Novosibirsk,

Russia


Polyfluoroindenyl cations are important intermediates in the reactions of

electrophilic substitution. They could be generated as long-lived ions at superacid media

of antimony pentafluoride for spectral

investigation by NMR spectroscopy. The

interest to this type of cations arises because of

their ambiguous nature. Formally they have

antiaromatic character and this fact is known for

nonfluorinated indenyl cation. But it was shown

that aromatic features increase with a number of

F atoms as substitutions which stabilize cation

[1]. At the same time heptafluoroindenyl cation still has not been investigated in detail

by NMR when it is well known that NMR-parameters reflect geometrical and electronic

character of structure [2]. We registered 19

F and 13

C NMR spectra and interpreted them

with a help of theoretically obtained data. In order to reach accurate correspondence

between calculated and experimental data the influence of anions on heptafluoroindenyl

cation should be taken in consideration. Even in a simple case of SbF6-

anion we

reached better agreement of calculated 19

F and 13

C chemical shifts with experimental. It

can witness indirectly the existence of heptafluoroindenyl cation with anion as close

ionic pair at a media of antimony pentafluoride. We also noted an increase of accuracy

of calculated spin-spin coupling constants JCF and JFF considering anion interaction.

Decomposition of these constants into Ramsey contributions allows us to find a number

of correlations with referring to chemical shifts and electronic structure of the cation.

This study was supported in part by the Russian Foundation for Basic Research (N14-

03-31279).

1. V.M. Karpov, V.E. Platonov, G.G. Yakobson, Tetrahedron, V.34, I.21, 1978, P.

3215-3218

2. V.M. Karpov, V.E. Platonov, L.N. Shegoleva, Zh. Org. Khim., V.34, I.11, 1998, P.

1732-1737.

Poster 7

48

Kinetics and mechanism of the reversible photoinduced

oxidation of purine nucleotides in aqueous solutions.

Natalya N. Fishman1,2

, Olga B. Morozova1, Mikhail S. Panov

1,2,

Günter Grampp3 and Alexandra V. Yurkovskaya

1,2

1International Tomography Center, Institutskaya 3a, 630090, Novosibirsk, Russia

2Novosibirsk State University, Pirogova 2, 630090, Novosibirsk, Russia

3Institute of Physical and Theoretical Chemistry, Graz University of Technology, Stremayrgasse 9,

8010 Graz, Austria


As photosensitized electron transfer from purine DNA nucleotides mediated by

triplet-excited exogenous chromophores, such as flavins, anthraquinones,

benzophenones, is important in biological systems, in present work we study the photo-

oxidation reaction of purine nucleotides adenosine-5′-monophosphate (AMP) and

guanosine-5′-monophosphate (GMP) by water-soluble benzophenone derivative –

3,3′,4,4′-benzophenone tetracarboxylic acid (TCBP). We have combined two

techniques, namely the Time-Resolved laser flash photolysis (LFP) and the Time-

Resolved Chemically Induced Dynamic Nuclear Polarization (CIDNP) and compared

reactivity of AMP and GMP towards TCBP triplets in aqueous solutions of different pH

at room temperature in order to provide further information on the acid-base properties

of radical intermediates observed in the photo-oxidation reactions of purines in aqueous

solution. The pH dependence of the observed quenching rate constant was measured by

LFP and explained in terms of reactants pKa values. As a result, the quenching rate

constants for each pair of reactants were determined by simulating the pH dependence

of the quenching rate constant observed. In acidic solution (pH<4.9), the quenching rate

constant is close to the diffusion-controlled limit kq=1.3×109 M

−1s

−1 (GMP), and

kq=1.2×109 M

−1s

−1 (AMP), whereas in neutral and basic solutions it is significantly

lower: kq=2.6×108 M

−1s

−1 (GMP, 4.9<pH<9.4), kq=3.5×10

7 M

−1s

−1 (GMP, pH>9.4),

kq=1.0×108 M

−1s

−1 (AMP, pH>6.5). Surprisingly, the strong influence of protonation

state of phosphoric group on the oxidation of AMP is revealed: deprotonation of the

AMP phosphoric group (6.5) decreases the quenching rate constant from 5.0×108

M−1

s−1

(4.9<pH<6.5) to 1.0×108 M

−1s

−1 (pH>6.5). A complimentary study on the pH

dependence of the geminate CIDNP intensity by time-resolved CIDNP enabled us to get

information on transient radical intermediates and to establish detailed mechanisms for

the reactions between the triplet TCBP and GMP or AMP.

This work was supported by the program of RFBR (Projects No. 13-03-00437, No.

14-03-31563, No. 14-03-00453, No. 14-03-00397), Grant No. MD-3279.2014.2 of the

President of the Russian Federation.

Poster 8

49

Photooxidation of histidine by 3,3′,4,4′-benzophenone

tetracarboxylic acid in aqueous solution studied by time-

resolved and field-dependent CIDNP

Mikhail S. Panov1,2

, Alexey S. Kiryutin1, Natalya N. Fishman

1,2,

Olga B. Morozova1, and Alexandra V. Yurkovskaya

1,2

1International Toomography Center, Institutskaya 3a, 630090, Novosibirsk, Russia



The interaction of excited triplet states of aromatic carbonyl compounds with amino

acids is of ongoing interest since many years. The nature of this interaction is attributed

to an electron transfer reactions, which play a significant role in biological processes

due to the migration of charge over long distance through peptide chains. Although, the

reactivity of histidine (His) toward the triplet-excited dyes is usually much lower than

that of tryptophan (Trp) and tyrosine (Tyr), earlier we found the new dye 3,3 ,4,4 -

benzophenone tetracarboxylic acid (TCBP), the excited triplets of which could be

quenched with comparable efficiencies by Trp, Tyr, and His in neutral to basic aqueous

solutions [1]. By the analysis of the pH dependences of both the geminate CIDNP and

the quenching rate constant for the His/TCBP at pH 6–9 it was proposed that the

mechanism of fully deprotonated 3TCBP quenching by His is the proton coupled

electron transfer. However the structure of radicals formed in the quenching reaction

was not determined. To remedy the situation and to determine magneto-resonance

parameters of His and TCBP radicals, in this work we used 13

C-Time-Resolved CIDNP

technique to get 13

C CIDNP spectra and field-cycling CIDNP to measure CIDNP field

dependence. As a result, relative values of 13

C isotropic HFCCs in TCBP and His

radicals were obtained from the 13

C-time-resolved CIDNP spectrum, recorded by the

photoreaction of TCBP with His with a natural abundance of magnetic isotope 13

C.

Good agreement was found for hyperfine coupling constants for TCBP ketyl radical

calculated using density functional theory methods and obtained by 13

C-time-resolved

CIDNP. The mechanism of the quenching reaction of triplet-excited TCBP by His in

neutral aqueous solution was established. 1H CIDNP field dependencies for the

photoreaction of TCBP with His were obtained and g-factor for histidyl radical was

found.

Financial support by the program of RFBR (Projects No. 13-03-00437, No. 14-03-

31563, No. 14-03-00453, No. 14-03-00397), Grant No. MD-3279.2014.2 of the

President of the Russian Federation is gratefully acknowledged.

[1] N. N. Saprygina, O. B. Morozova, G. Grampp, A. V. Yurkovskaya, J. Phys. Chem. A, 2014, 118,

339-349.

Poster 9

50

Atomistic molecular dynamics simulations of cyanobiphenyl

compounds

Egor Gerts, Andrei V. Komolkin

Faculty of Physics, St. Petersburg State University, 198504, Ulyanovskaya 3,

St. Petersburg, Russia


Liquid crystalline materials are very interesting objects for the researchers. They

are used not only in technological devices. Some biological systems also possess sort of

liquid crystallinity. Cell membranes form lamellar bi-layer mesophase, and this is the

case for cancer cells as well. One of the difficulties in the development of effective

anticancer drugs is the transportation of the drug inside the cell. And liquid crystals can

be rather useful in solving this problem. Some recent papers [1-3] showed that certain

cyanobiphenyl compounds can inhibit cell growth and even recognize normal and

cancer cells. Although the anticancer activity was observed, its mechanism still stays

unclear.

This work focuses on two cyanobiphenyl compounds: thermotropic nematic liquid

crystal 4-cyano-4’-(6-hydroxyhexyloxy)biphenyl (HO-6OCB) and 4-methyloxy-4’-(6-

hydroxyhexyloxy)biphenyl (HO-6OMeOB), that does not form mesophase. Local and

conformational structures of these substances and their equimolar mixture are studied

via fully atomistic molecular dynamics simulations. This information will help to

investigate the mechanisms of intermolecular interactions, thus giving insights into the

development of novel anticancer drugs.

Acknowledgements. It is a pleasure to thank Saint-Petersburg State University for

the research grant 11.37.159.2014. Research was carried out using computational

resources provided by Resource Center ”Computer Center of SPbU” (http://cc.spbu.ru).

References.

[1] Yoshizawa, Atsushi, et al. "Biological activity of some cyanobiphenyl

derivatives." Chemistry Letters 38, 6 (2009): 530-531.

[2] Takahashi, Yuuka, et al. "Supramolecular assembly composed of different

mesogenic compounds possessing a ω-hydroxyalkyl unit exhibits suppressive effects on

the A549 human lung cancer cell line." MedChemComm 2, 1 (2011): 55-59.

[3] Ishikawa, Junya, et al. "Suppressive effects of liquid crystal compounds on the

growth of U937 human leukemic monocyte lymphoma cells." Cancer Cell Int 12, 3

(2012).

http://cc.spbu.ru/

Poster 10

51

Functional EPR Imaging of Isolated and Perfused Rat Hearts:

Monitoring of Tissue pH and Oxygenation

Artem A. Gorodetsky, Denis A. Komarov

Novosibirsk Institute of Organic Chemistry, 9 Lavrent’ev Ave., 630090, Novosibirsk,

Russia


Ischemic heart disease is one of the most common causes of mortality in the

developed countries. Violation of the coronary blood supply leads to a lack of oxygen

supply and metabolic substrates to a myocardium, as a result significant changes occur

in the myocardial tissue microenvironment which can lead to permanent damage of the

cardiomyocytes.

Comprehensive studies of myocardial tissue microenvironment are necessary for

understanding the mechanisms of ischemic injury and for the development of new

therapeutic approaches in the treatment of ischemic heart disease. Electron

paramagnetic resonance technique in conjunction with paramagnetic probes allows

noninvasive monitoring functional parameters of living biological objects; furthermore,

the application of EPR imaging methods provides a unique opportunity for visualization

of the tissue microenvironment.

The main aim of this work was to visualize myocardial acidosis and oxygenation in

isolated and perfused rat hearts during local ischemia by EPR imaging technique.

Isolated rat hearts were perfused directly in a resonator of an L-band EPR spectrometer

by method of Langerdorff at a constant flow. Contractile function of the hearts was

continuously monitored during the experiment using a water-filled latex balloon

inserted into the left ventricular and connected to a pressure transducer. Local ischemia

was induced by ligation of the left anterior descending coronary artery. A specially

designed pH-sensitive nitroxide radical was used for visualization of myocardial pH. A

perdeuterated 15

N nitroxide radical was synthetised and employed as a pO2-sensitive

probe for visualization of myocardial oxygenation during ischemia and reperfusion.

A map of pH of an isolated and perfused rat heart during local ischemia was

obtained and a significant acidification of ischemic area was observed down to pH 6.7 -

6.9. Also the maps of oxygenation of a heart were obtained during ischemia using pO2-

sensitive nitroxide radical and a significant decrease in the oxygen concentration was

observed in the ischemic area. In summary, this work demonstrates capability of low-

field EPR technique in combination with specially designed soluble paramagnetic

probes for visualization of functional parameters of living tissues and organs.

Poster 11

52

Proton NMR study of hydrogen site occupancy and mobility

in hydrides of disordered transition metal alloys

V.O. Ievleva1, A.V. Vyvodtceva

1, M.G. Shelyapina

1, A.V. Ievlev

1,

S.A. Lavrov1, A. Privalov

2, N.E. Skryabina

3, A. Aleksanyan

4, D. Fruchart

5

1Faculty of Physics, St Petersburg State University, St Petersburg, Russia,

2Institute für

Ferstkoerperphysik, TU Darmstadt, Darmstadt, Germany, 3Faculty of Physics, Perm State

University, Perm, Russia, 4A.B. Nalbandyan Institute of Chemical Physics of Armenian

NAS, Yerevan, Armenia, 5MCMF Institut Néel, CNRS, Grenoble, France


Because of their potentially high hydrogen absorption capacity, the early transition

metal alloys with bcc lattice have been a subject of intensive experimental and

theoretical studies [1]. For better understanding of intrinsic mechanisms that govern the

hydrogen kinetics in these hydrides the deeper knowledge on local structure and

hydrogen mobility is required. Being a powerful tool to investigate metal-hydrogen

systems, nuclear magnetic resonance (NMR) can provide a comprehensive insight on

main characteristics (static and dynamic) of their microstructure. Here we report on the

result of our recent 1H NMR study (cw spectroscopy, relaxation measurements and

diffusometry) of hydrides of disordered binary Ti-Nb, Ti-V and ternary Ti-V-Cr alloys

with the H/M ratio close to 2. To treat the cw-NMR data the KKR-CPA calculation

were carried out. The result can be summarized as follows. In hydrides of ternary Ti-V-

Cr alloys the 1H NMR spectrum consists of two lines, narrow and broad ones, which

correspond to two states of hydrogen, more and less mobile, respectively. The broad

line can be attributed to the hydrogen localized in tetrahedral interstitial sites of the fcc

lattice [2]. In hydrides of binary Ti-V and Ti-Nb alloys an additional broad line appears.

This line can be attributed to the partly occupied octahedral hydrogen sites. The ratio

between the integral intensities of the broad and narrow components of the 1H NMR

line depends on temperature: at low temperature the hydrogen motion is frozen and the

narrow line disappears, whereas at high temperature all the hydrogen atoms are in

mobile state. However, in relaxation measurements only the narrow component is

observed, and the weight of the “faster” hydrogen fraction can be determined from the

free induction decay amplitude of the 1H NMR signal. The temperature dependence of

“faster” hydrogen fraction can be perfectly fitted by the logistic distribution function.

To explain the temperature dependencies of the spin-lattice relaxation times we

developed a model, which supposes an exchange between hydrogen states with different

mobility [3]. Using this model we have determined parameters characterizing the

hydrogen mobility: activation energies and correlations times. Spin-lattice relaxation

measurements of Ti-V-Cr hydrides, treated within the exchange model, confirm that

activation processes starts earlier in the vanadium reach hydrides. That is also in

agreement with our diffusion measurement.

References

[1] E. Akiba, H. Iba, Intermetallics 6 (1998) 461.

[2] V.S. Kasperovich et al., J.Alloys Compd. 509 (2011) S804.

[3] V.I. Chizhik et al., Int. J. Hydrogen Energy 36 (2011) 1601.

Poster 12

53

Investigation of antimicrobial peptide alamethicin pore

formation in the membrane of Bifidobacteria cell by EPR

Isaev N.P.1, Samoilova R.I.

1, De Zotti M.

2, Formaggio F.

2 Toniolo C.

2 and Raap J.

3

1Institute of Chemical Kinetics and Combustion, Institutskaya-3, 630090

2UniVersity of Padova, 35131 Padova, Italy

3Leiden Institute of Chemistry, Gorlaeus Laboratories


The development of antibiotics may be the greatest scientific invention that saved

millions of lives and significantly increased life expectancy. However its excessive

usage formed bacterial resistance that grows faster than new drugs are designed.

Antimicrobial peptides which are the part of organism defense system may be a

possible alternative to classical antibiotics. Its mechanism of action is under hard

investigation. The most common approaches use model membrane systems and it was

shown that some peptides may form membrane pores at high peptide/lipid concentration

(around 1/20) via barrel stave or toroidal pore mechanisms. Pores formation leads to

increased membrane permeability and cell death. Bacterial membrane morphology and

composition differs a lot from model ones, but to our very best knowledge so far there

are only three works that attempt to investigate peptides mechanism of action directly in

bacteria cells [1-3].

In this work we investigated pore formation mechanism of spin-labeled peptide

alamethicin in Bifidobacterium cells using CW EPR and PELDOR. Alamethicin is

water insoluble, so we also studied efficiency of its delivery to bacteria by unilamellar

liposomes and SDS micelles.

1. A. D. Milov, R. I. Samoilova, Yu. D. Tsvetkov, V. A. Gusev, F. Formaggio, M.

Crisma, C. Toniolo, J. Raap; Appl. Magn. Reson. 23, 81-95 (2002)

2. Gee M.L., Burton M., Grevis-James A., Hossain M.A., McArthur S., Palombo E.A.,

Wade J.D., Clayton A.H., Sci Rep., 3:1557 (2013)

3. Avitabile C., D'Andrea L.D., Romanelli A., Sci Rep., 4:4293 (2014)

Poster 13

54

Theory of pulsed reaction yield detected magnetic resonance

Egor Nasibulov1,2

, Leonid Kulik3, Jan Behrends

4, Robert Bittl

4, Konstantin Ivanov

1,2

1 International Tomography Center SB RAS, Institutskaya 3a, Novosibirsk 630090, Russia. E-mail:

[email protected]

2 Novosibirsk State University, Pirogova 2, Novosibirsk 630090, Russia

3 Institute of Chemical Kinetics and Combustion SB RAS, Institutskaya 3, Novosibirsk 630090, Russia

4 Freie Universität Berlin, Arnimallee 14, Berlin 14195, Germany

We have developed the theory of pulsed Reaction Yield Detected Magnetic Resonance

(RYDMR) and suggest analogues of the main EPR pulse sequences in the case of non-

selective mw-pulses. We have used refocusing of the zero-quantum coherences in the

Radical Pair (RP) and formulated a criterion for observing spin echoes in RYDMR

where not the spin magnetization but the singlet state population is used as an

observable. An alternative way to monitor the spin echo is given by monitoring the

longitudinal magnetization in an RP after applying an additional 90-degree non-

selective pulse. The primary echo sequence has been studied, which can be extended to

an analogue of the Carr-Purcell sequence with multiple echoes coming from subsequent

pulses. We have suggested an Electron Spin Echo Envelope Modulation (ESEEM)

pulse sequence for observing modulations caused by the electronic spin-spin

interactions that can be used to probe the distance between the radicals in the RP.

Finally, analogues of the stimulated echo sequence and the Mims ENDOR (Electron

Nuclear Double Resonance) sequence have been proposed. The treatment was also

extended to RYDMR with selective pulses; in this case we considered refocusing of

both zero-quantum and single-quantum coherences. This enables extending the

capabilities of pulsed RYDMR even further, for instance, by using pulse sequences of

the ELDOR (Electron Electron Double Resonance) type, which can be used for

measuring electron-electron interactions in the RP.

The theoretical results can be used to extend the scope of RYDMR spectroscopy

and fully exploit its potential. In combination with the high sensitivity of RYDMR,

techniques using pulsed methods can provide new attractive options for more detailed

study of structure, dynamics and reactivity of the short-lived RPs and properties of

paramagnetic charge carriers in organic semiconductors.

This work was supported by grant MD-3279.2014.2 of the President of RF and

Alexander von Humboldt Foundation.

Poster 14

55

Spin dynamics of ZnTPP in room-temperature ionic liquids

studied by Time-Resolved EPR

Ivanov Mikhail Y., Veber Sergey L., Fedin Matvey V.

International Tomography center, SB RAS, Intitutskaya 3a, 630090, Novosibirsk, Russia


Room temperature ionic liquids (RTILs) have drawn a significant attention of

scientific community during last few decades. This interest is caused by unique

properties exhibited by RTILs on macro- and microscopic scales, including their

thermo-stability, negligible vapor pressure, high viscosity and ability to form micro-

ordered structures in supercooled state. One of the interesting applications of ILs

concerns their influence on the formation of chemical induced electron polarization

(CIDEP) in photo-excited triplet molecules and during photochemical reactions. Up to

date, only one study of CIDEP in photo-excited triplet molecules in ILs using time-

resolved electron paramagnetic resonance (TR EPR) has been reported [1].

In this work we have studied CIDEP of zinc tetraphenylporphyrin (ZnTPP) in two

ILs ([bmim]PF6 and [bmim]BF4) of significantly different viscosity. It has been

assumed that high micro-viscosity of IL should affect the rotational motion of ZnTPP

and, consequently, the electron relaxation times between triplet sublevels. We used X-

band (9 GHz) TR EPR as one of the most appropriate methods for studying spin

dynamics of triplet molecules. The temperature dependence of micro-viscosity of

[bmim]PF6 and [bmim]BF4 in the range of 230÷294 К has been preliminarily studied by

EPR of nitroxide spin probes. Inhomogeneous freezing and micro-structuring

phenomena have been found in IL [bmim]PF6. Remarkably, owing to the high viscosity

of ILs used, the photo-excited triplet state of ZnTPP has been detected even at room

temperature, in agreement with [1]. The detailed analysis of temperature-dependent TR

EPR kinetics has been performed, which revealed crucial influence of micro-ordered

structure of RTILs on the electron relaxation rates in photo-excited triplet ZnTPP.

[1] Kawai A., Hidemori T., Shibuya K.: Molecular Physics, 2006, 104:10-11,1573–

1579.

Poster 15

56

Adaptation of NMR Imaging Techniques for Experimental

Mapping of the Static Magnetic Field

Viacheslav A. Ivanov, Viacheslav V. Frolov

Saint-Petersburg State University

Ulyanovskaya 1, Saint-Petersburg, 198504, Russia


Problem of static magnetic field homogeneity and getting the spatial field

distribution has always been an actual problem in NMR spectroscopy and imaging.

Conventional method of field scanning realized by small-size sample moving through

the volume of magnetic system and point-by-point field measuring is time-consuming,

not accurate and requires special equipment, therefore such methods which present field

map of the whole sample or at least its section after computer processing of NMR data

are an object of interest. Such methods can be developed on the basis of NMR imaging

techniques.

Tomographic methods of getting magnetostatic field spatial distribution realized

previously by their authors in strength field were studied. Experimental MRI scanner

control program in LabVIEW development environment was modified to perform the

experiments. Picture of field distribution on cylindrical sample, 35mm in diameter was

obtained as a result of the experiment. Thus the possibility of getting spatial field

distribution in relatively short time using standart equipment with minimal control

program modification in weak magnetic field was demonstrated.


Poster 16

57

Controlled radical polymerization of styrene in the

presence of nitroxides at low temperatures

Beket B. Kanagatov,

a Dmitriy A. Parkhomenko,

a,b Maria V. Edeleva,

b Ludmila E.

Tatarova,c Vadim K. Khlestkin

a

a Novosibirsk State University, Pirogova str., 2, 630090, Novosibirsk, Russia

b Institute "International Tomografic Center", Institutskaya str., 3, 630090, Novosibirsk, Russia

c Institute of Cytology and Genetics, Lavrentieva pr., 10, 630090, Novosibirsk, Russia


Controlled radical polymerization (CRP) in the presence of nitroxides is a modern

method of producing polymers with a given structure, molecular weight and low

molecular mass distribution. CRP is usually carried out at elevated temperature, which

makes polymerization process energy consuming. Typical temperature for styrene

polymerization in the presence of nitroxide is 100-140oC. Lowering the temperature of

polymerization even by 10-20°C can provide significant economic and environmental

effects. There are only a few examples of the CRP at low temperature. For example,

Guillaneuf et al. [1] describe the use of α-hydrogenated linear nitroxides, which enables

the polymerization of styrene in a controlled manner at 60oC.

This work presents synthesis of a new cyclic nitroxide of imidazole series (Figure

1). Synthetic procedure consist of six stages. NMR and EPR spectroscopy were

employed to characterize the target product and intermediates of synthetic stages. The

nitroxide was used for the polymerization of styrene at 60oC. The kinetics of

polymerization was studied by means of NMR spectroscopy. It was shown that the

polymerization is possible up to high monomer conversion (80-90%). Gel permeation

chromatography allowed to determinate molecular mass and molecular mass

distribution of the final polymer. It is shown that the polymerization proceeded in a

controlled manner as the obtained polydispersity of the polymer was 1.45 at 50% of

monomer conversion, which is below the theoretical limit for a regular uncontrolled

radical polymerization.

Figure 1

1. Guillaneuf, Y., Lamps, J. P., Catala, J. M., Gigmes, D., Drockenmuller, E. J. Polym. Sci. Part A:

Polym. Chem.2012, 50, 3750-3757.

This work was supported by RFBR (project number 12-03-01042a), OHNM 5.1.1,

President grant MK-1654.2013.3


Poster 17

58

Application of pulse EPR for investigation of lipid-

cholesterol rafts in membranes

Maria E. Kardash, Nikolay P. Isaev, Sergey A. Dzuba

The Institute of Chemical Kinetics and Combustion, Institutskaya, 3, 630090, Novosibirsk, Russia


Lipid rafts are ordered regions of the lipid bilayer of the cell membrane. Rafts play

important role in membrane proteins functions regulation, but its molecular structure is

still unknown.

Lipid rafts are known to form in a ternary mixture of cholesterol and two lipids

with different melting points. The "solid" lipid aggregates with cholesterol. Here we

investigated the aggregation of cholesterol in model membranes of different lipid

composition.

In the present study spin echo phenomenon, so-called "instantaneous spectral

diffusion", was used to investigate the stage of cholesterol aggregation. Instantaneous

diffusion arises due to the dipole-dipole interactions between neighboring electron spins

and contributes echo decay exponentially. Its rate is proportional to the local

concentration of spin labels.

It was shown that method of "instantaneous diffusion" is applicable to investigate

the aggregation of cholesterol in biological membranes. Local concentration of

aggregated spin-labeled cholesterol increases several times relative to its average

concentration in the membrane.

.

Poster 18

59

EPR Study of Electron-Acceptor Sites during Catalytic

Dehydrochlorination of 1-Chlorobutane over

Nanocrystalline MgO

Roman M. Kenzhin1, Tatyana N. Akimova

2, Ekaterina I. Shuvarakova

1,3, Vladimir V.

Chesnokov1,2

, Alexander F. Bedilo1,3

1 Boreskov Institute of Catalysis SB RAS, pr. Lavrentieva, 5, 630090, Novosibirsk, Russia

2 Novosibirsk State Technical University, pr. K. Marksa, 20, 630078, Novosibirsk, Russia

3 Novosibirsk Institute of Technology, Moscow State University of Design and Technology, Potaninskaya,

5, 630099, Novosibirsk, Russia


It was shown earlier that the catalytic activity in dehydrochlorination of 1-

chlorobutane over nanocrystalline MgO substantially increases with time due to the

MgO conversion to MgCl2 [1]. This increase coupled with a decrease of the surface area

indicates that more active catalytic sites are formed on the surface during this reaction.

Recently we reported that weak electron-acceptor sites formed due to the MgO

halogenation may be responsible for solid-state reaction between nanocrystalline MgO

and CF2Cl2 [2]. In this study we characterized by EPR weak electron-acceptor sites

formed during this reaction using perylene as a spin probe, and found a good correlation

between their concentration and the catalytic activity.

Samples of aerogel-prepared nanocrystalline MgO and a commercial MgO sample

were studied in catalytic dehydrochlorination of 1-chlorobutane. 1-Chlorobutane

conversion to a mixture of butenes was monitored by gas chromatography. The

electron-acceptor sites were characterized using perylene adsorption from 2x10-2

M

solution in toluene. The catalytic activity was found to increase significantly during the

1-chlorobutane dehydrochlorination reaction, which is accompanied by modification of

the MgO surface and bulk with chloride ions. No electron-acceptor sites were observed

on the surface of initial MgO samples. They appeared only during the reaction. Their

concentration normalized per unit mass gradually increased during the reaction due to

the surface chlorination. A good correlation was observed between the catalytic activity

and the concentration of weak electron-acceptor sites. The obtained results indicate that

weak electron-acceptor sites tested using perylene may be the active sites accounting for

1-chlorobutane dehydrochlorination in the active state of the catalyst.

This study was supported in part by Russian Foundation for Basic Research (Grant

13-03-12227-ofi-m).

[1]. I.V. Mishakov, A.F. Bedilo et al., J. Catal. 206, 40-48 (2002).

[2]. A.F. Bedilo, E.I. Shuvarakova et al., J. Phys. Chem. C, 118, 13715-13725 (2014)

Poster 19

60

CIDNP in Naproxen - Pyrrolidine Dyads as a Model of Drug-

Enzyme Binding.

Ekaterina A. Khramtsova, Viktor F. Pluysnin, Ilya M. Magin, Tatyana V.

Leshina

Voevodsky Institute of Chemical Kinetics and Combustion SB RAS, Institutskaya str., 3,



At present a timely problem is the investigation of the mechanisms of remedies

action on cellular and molecular levels. According to a modern view the mechanism of

medicine’s action accounts for the interaction of the active part of remedy molecule

with an enzyme. On a molecular level it generalizes to various so-called weak

interactions such as the formation of charge transfer complexes, hydrogen bonds, Van

der Waals and dipole-dipole interactions. It is widely thought that such interactions are

originated between a medicine and an amino-acid residue in the active site of an

enzyme. Under studying the regularities by which these interactions are obeyed model

systems are often used. Linked systems are most popular, such molecules contain a

donor and an acceptor connected with covalent bridges. Typically photoinitiation is

used for modeling and then the main mechanism of donor-acceptor interaction turns out

electron transfer (ET).

In this study the effects of photo CIDNP and the rates of fluorescence quenching in

three linked systems in different polarity media are analyzed, molecules contain N-

methyl pyrrolidine as a donor and naproxen as an acceptor group. The choice of the

system is due to following facts: the molecular mechanism of the action of non-steroidal

anti-inflammatory drugs, including well-known brand “Naproxen” – (S)-2-(6-methoxy-

2-naphtyl) propionic acid, lies in the binding of a remedy with amino-acid residues in

the cyclooxygenase (COX) active site. COX is a bifunctional enzyme, which performs

two activities – the cyclization of the natural substrate’s molecule and the transfer of

two electrons, that is why the ET investigation in model system is of some interest.

Obtained in this work results have demonstrated the high sensitivity of CIDNP

effects and the rates of fluorescence quenching in dyads to the influence of solvent

polarity and also to the donor/acceptor spatial position. It is quite well agreed with

previously postulated conclusions in molecular biology about the role of steric factors in

the process of naproxen-binding in COX active site.

The work was supported by the Russian Foundation for Fundamental Research

(grant 14-03-00192 A).

Poster 20

61

FMR of iron-containing nanocomposites of natural

polysaccharides

Khutsishvili S.S., Alexandrova G.P., Vakul’skaya T.I., Sukhov B.G.

A.E. Favorsky Irkutsk Institute of Chemistry Siberian Branch of the Russian Academy of

Sciences, Favorsky street, 1, 664033, Irkutsk, Russia


The ferromagnetic properties of nanocomposites based on natural

polysaccharides (arabinogalactan, galactomannan, carrageenan) and iron oxides

(magnetite nanoparticles), that, being covered by natural high molecular polymers, form

stable aggregation magnetic nanomaterials, have been investigated.

All the nanocomposites to a greater or lesser extent possess the ferromagnetic

properties at room temperature that has been confirmed by measurements of their

magnetization. By example arabinogalactan, the similar characteristics of FMR spectra

of the investigated nanocomposites are the asymmetric broad absorption lines,

indicating small changes in size and shape of the nanoparticles formed (for the

nanocomposites containing iron from 3.5 to 6.4%). The greatest change in the magnetic

properties of iron-containing nanomaterials is connected with the change of the domain

structure of magnetic-ordered systems at increasing particles' sizes. Dramatic changes in

the spectra character are observed at increasing iron content up to 9.2-12.5%. The

appearance of several absorption lines, which position varies at different amount of

microwave power, testifies the substantial change of nanoparticles' distribution, the

increasing of the latter sizes and the possible change of domain structure. It accords

with the appearance of inflection point at iron content 6.4% in the nanocomposites on

the dependences of geff-factor and width of EPR signal, magnetization parameters and

nanoparticles' sizes on percentage iron content in the nanocomposites and with the

found relation of magnet-activity to the sizes of the nanoparticles.

Prolonged storage of the nanocomposites has shown that at least a year there are

the stable metal nanoparticles, maintaining the EPR characteristics.

This work was supported by the Russian Foundation for Basic Research (Grants 11-

03-00022 and 14-03-00859_a).

Poster 21

62

Lipid peroxidation. Bistability and bifurcation phenomena.

Magnetic field effects

A. A. Kipriyanov, Jr.1,♦

and P. A. Purtov1,2,♠

1Voevodsky Institute of Chemical Kinetics and Combustion Siberian Branch of the Russian Academy of

Sciences, Institutskaya 3, 630090, Novosibirsk, Russia


♦Email: [email protected]

♠Email: [email protected]

The response of living organisms to the change in the environment, including the

change of external magnetic field, is quite different. One of the feasible defense

mechanisms of organism adaptation to varying conditions is the activation of lipid

peroxidation reaction (LPR) which plays a key role in the life of cells (e.g., apoptosis or

necrosis). It is known that the normal conditions of cell vital activity involve a certain

level of LPR induced by the formation of active oxygen forms. Taking into account the

necessary of keeping certain LPR level under stationary conditions, it is assumed that

any change of LPR produces base response of living system to external action which

initiates other defense mechanisms of organism as a whole.

On the other hand, it is known that the reaction of lipid peroxidation follows a free-

radical chain mechanism in which the key role belongs to peroxide radicals LO2.

Therefore, according to the mechanism of radical pairs, this reaction is a potential target

of magnetic field effect on living systems.

We present theoretical results of investigation of magnetic field effect on LPR in

steady state condition. The model system under the investigation is an open

continuously stirred tank reactor which describes a living cell on the approximate level.

We show that under certain conditions in this reaction system, three steady states may

arise, two of which are stable and the third state is unstable. It is assumed that external

magnetic field could effect on the rates of radical reactions occurring in the system.

This, in turn, leads to bifurcation of the non-equilibrium stationary state and, thus, to a

drastic change in the concentration of reactants

.

Poster 22

63

EPR study of the hydrogen center in HPHT diamonds grown

in carbonate medium

Andrey Yu. Komarovskikh1, Vladimir A. Nadolinny

1, Yuri N. Palyanov

2, 3,

Igor N. Kupriyanov2, 3

, and Alexander G. Sokol2, 3

1Nikolaev Institute of Inorganic Chemistry SB RAS, Acad. Lavrentiev Ave., 3, 630090,

Novosibirsk, Russia 2Sobolev Institute of Geology and Mineralogy SB RAS, Acad. Koptyuga Ave., 3, 630090,

Novosibirsk, Russia 3Novosibirsk State University, Pirogova str., 2, 630090, Novosibirsk, Russia


The issue of hydrogen incorporation into a diamond is one of the topical problems

of diamond field. Hydrogen is very widespread contamination, it being found both in

natural and synthetic diamonds. Hydrogen is technologically important impurity in

diamond effecting its conductivity. Up to date hydrogen-containing paramagnetic

centers have been found only in synthetic CVD diamonds. And hydrogen incorporation

in this case is connected with large amount of hydrogen in the precursor gas.

In this work new hydrogen containing paramagnetic center has been revealed by

EPR in diamonds grown at HPHT conditions in the Na2CO3–CO2–H2O–C system. In

the EPR spectra of the studied samples there are spectra of the substitutional nitrogen

atom, previously detected defects attributed to oxygen and the new spectrum (labeled

VOH). Study of the EPR spectra in X and Q frequency bands has shown that new

spectrum is characterized by the appearance of forbidden transitions along with allowed

ones. The analysis of the angular dependence of the spectrum in single crystal and the

analysis of powder spectra give an information that the spectrum is caused by

interaction with the nucleus of a hydrogen atom 1H and described by the spin

Hamiltonian with the following parameters: S=1/2, I=1/2, g =2.0030(1), g||=2.0023(1),

A(H) =10.7(3) Gs, A(H)||=11.8(3) Gs.

The high concentration of oxygen centers in the studied samples indicates a

possibility of oxygen incorporation into the structure of this defect. So on the basis of

EPR data on electronic state and symmetry of the VOH center the center is supposed to

have a model of vacancy–oxygen–type defect containing a hydrogen atom. In such a

model, the motional averaging may result in the C3v symmetry of the EPR spectrum.

In the IR absorption spectra of the studied diamonds a group of lines (in the range

of 3000 cm-1

) indicating the formation of C–H bonds was detected. This is

complementary evidence of hydrogen incorporation into the structure of the considered

diamond crystals.

Poster 23

64

The study of influence of sugars on the mobility of

phospholipid bilayer

K. B. Konov1, N. P. Isaev

2, S. A. Dzuba

2,3

1 Kazan Physical -Technical Institute, Kazan, 420029, Russia

2 Institute of Chemical Kinetics and Combustion, Novosibirsk, 630090, Russia

3 Novosibirsk State University, Novosibirsk, 630090, Russia


Sugars, such as sucrose and trehalose, can protect biological cell and its interior

from damaging by freezing and desiccation [1]. There are two main hypothesis about

how sugars protect the cell. The water replacement hypothesis asserts that sugars

aggregate in vicinity of polar heads of phospholipids replacing the surrounding water

[2]. Sugars form hydrogen bonds with lipids polar groups stabilizing phospholipid

bilayer [3]. The another hypothesis states that sugars are excluded from membrane

surroundings and act only by changing a properties of intercellular liquid.

In this work we study the mobility of lipid bilayer by electron spin echo technique.

The model bilayer was made of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC)

lipid and spin labeled stearic acid. Spin labels were attached at 5th

and 16th

position of

acyl chain. Electron spin echo technique can give useful information about the mobility

in the middle of lipid bilayer and near the surface level at temperature range from 80K

to 250K.

The obtained data shows that the action of trehalose and sucrose differ from each

other.

[1] Crowe J.H., Crowe L.M. et al., Carpenter etal., Biochimica et Biophysica Acta,

1988, 947(2), 367-84.

[2] Golovina E. A., Golovin A. V. etal., Biophysical Journal, 2009, 97, 490–499

[3] Geert van den Bogaart, N. Hermans etal., Biophysical Journal, 2007, 92, 1598–

1605

Poster 24

65

Effect of a heavy atom on magnetic anisotropy of

monobromine substituted septet trinitrene. Experimental

and theoretical (ab initio and DFT) study.

Denis V.Korchagin, Artem A. Mazitov, Aleksander V.Akimov, Sergey V. Chapyshev

and Eugenii Ya. Misochko

Institute of Problems of Chemical Physics Russian Academy of Sciences, Russian

Federation [email protected]

Recently we have been observed the effect of a heavy atom in the high-spin

molecules of nitrenes, which consisted of the large spin-orbit contribution to the

parameter D (DSOC

) and, as the result, a significant change not only the magnitude but

even the sign of the magnetic anisotropy parameter Dtotal

[1]. In continuation of this

work we present an experimental and theoretical study of the ZFS parameters of 1-

bromo-3,5-dichloro-2,4,6-trinitrenobenzene molecule (1).

1

EPR spectrum of matrix-isolated in solid argon (5K) of this septet (S = 3) in the

ground state molecule of trinitrene 1 was detected. From EPR spectra it has been

determined with high precision the parameters of tensor D. The values obtained were

used as reference for a detailed theoretical analysis of the ZFS parameters of molecule

1. By the high-level ab initio and DFT methods the calculations of the tensor D

parameters were performed, including both analysis spin-spin and spin-orbit

contributions to the total D value, and also orientations of DSS

and DSOC

tensors. The

high-level ab initio quantum chemical calculations have shown that the main

contribution to the DSOC

make transitions involving p-orbitals of the heavy halogen

substituent in the plane (right figure).

[1] Misochko, E. Ya.; Akimov, A. V.; Masitov, A. A.; Korchagin, D. V.;

Yakushchenko, I. K.; Chapyshev, S. V. J. Chem. Phys. 2012, 137, Article No. 064308.

Acknowledgements – This work was financially supported by the Russian Foundation for Basic Research (grant 13-03-00757) and the Russian Academy of

Sciences (program OX-1).


Poster 25

66

Inclusion compound of threonin with cucurbit[7]uril -

supramolecular chemistry in solution

Ekaterina A. Kovalenko

Nikolaev Institute of Inorganic Chemistry SB RAS, Acad. Lavrentiev Ave., 3,


[email protected]

NMR is one of the method which can yield information about the inclusion complex on

an atomic level. This method offers the advantage of providing insights into dinamic

processes as well as structural information at a molecular level. Complexation of CB[n]

with guests molecules causes changes in the chemical shifts of the protons belonging to

the CB[n] and/or guest molecule. We measured 1H NMR spectra for system D,L-treonin

and cucurbit[7]uril in different conditions: concentration, temperatire, pH values.

Sequential adding of three fixed CB[7] amounts resulted in each aminoacid proton

signal chemical shift up field change by a different value, the multiplet structure of

aminoacids lost forming unresolved signals. 1H NMR spectra of aminoacid and CB[7]

mixture in solution demonstrated the existence of chemical equilibrium between free

aminoacid molecules (racemic mixture of treonin and allo-treonin) and associated with

CB[7] aminoacid molecule. With a change of concentration the CB[7] signals are

practically stable to be singlet, doublet and doublet.

Fig. 1. Threonine Fig. 2. 1H NMR spectra of Thr racemate, Thr racemate:

CB[7] in the molar ratio 3,4:1, 1,7:1, 1,1:1

(upwards) in DCl

The work is financially supported by Russian Federation President Grant MK-

2514.2014.3 and RFBR 14-03-31177.


Poster 26

67

Advanced SDSL with Nitroxyl and Trityl Radicals for

Distance Measurements in Nucleic Acids

O.А. Krumkacheva1,2

, M.V. Fedin1,2

, E.G. Bagryanskaya1,2,3,

, A.A. Kuzhelev2,3

,

V.M. Tormyshev2,3

, I.A. Kirilyuk

2,3, A.V. Ivanov

4, A.A. Malygin

2,4, E.S. Babaylova

2,4,

G.G. Karpova2,4

, G.Yu. Shevelev2,4

, A.A. Lomzov2,4

, D.V. Pyshnyi2,4

1 International Tomography Center SB RAS, Novosibirsk, Russia

2 Novosibirsk State University, 630090, Novosibirsk, Russia.

3 N.N. Vorozhtsov Novosibirsk Institute of Organic Chemistry SB RAS, Novosibirsk, Russia

4Institute of Chemical Biology and Experimental Medicine SB RAS, Novosibirsk, Russia


Site-directed spin labeling (SDSL) is widely applied for structural studies of

biopolymers by EPR. In particular, huge attention has been drawn recently to pulsed

dipolar EPR spectroscopy (PELDOR/DEER and DQC methods) allowing distance

measurements in many biologically-important systems. Although significant progress

has been achieved in this field, a number of challenges still remain. One of these

challenges is SDSL of long (exceeding 50-70 base pairs) natural nucleic acids that is not

possible using common solid-phase synthesis. In this work, we propose novel SDSL

approach suitable for long natural RNAs, which is based on the attachment of linker

containing aliphatic amino group to the target nucleotide residue and following selective

coupling of spin label to this amino group [1]. Such linker can be attached to the desired

RNA residue via sequence-specific reaction with the derivatives of

oligodeoxyribonucleotides. To verify this approach, we applied it to model RNA duplex

with known structure and expected distance between corresponding residues. The

distance measured using Q-band pulse DEER corresponds well to the expected one.

Another current challenge in pulsed dipolar EPR spectroscopy is a design of spin

labels and SDSL strategies for distance measurements in nucleic acids at 300 K. For this

purpose, relaxation properties of trityl radicals represent a significant advantage. In this

work we report room-temperature distance measurement in trityl-labeled immobilized

DNA duplexes [2]. We succeeded to develop optimal trityl-based spin labels, efficient

SDSL and immobilization approaches that, working together, allowed us to measure as

long distances as ~4.6 nm with high accuracy at room temperature. This work was

supported by RFBR (No. 14-03-31839, 13-04-00680, 12-04-01435).

(1) Babaylova, E. S.; Ivanov, A. V.; Malygin, A. A.; Vorobjeva, M. A.; Venyaminova, A. G.; Polienko,

Y. F.; Kirilyuk, I. A.; Krumkacheva, O. A.; Fedin, M. V.; Karpova, G. G.; Bagryanskaya, E. G. Org.

Biomol. Chem. 2014, 12, 3129.

(2) Shevelev, G. Y.; Krumkacheva, O. A.; Lomzov, A. A.; Kuzhelev, A. A.; Rogozhnikova, O. Y.;

Trukhin, D. V.; Troitskaya, T. I.; Tormyshev, V. M.; Fedin, M. V.; Pyshnyi, D. V.; Bagryanskaya, E. G.

J. Am. Chem. Soc. 2014, 136, 9874.

Poster 27

68

Development of spin labels based on triarylmethyl radicals:

pulse and CW EPR study

A.A. Kuzhelev1,2

, O.A. Krumkacheva3,1

, O.Yu. Rogozhnikova2,

V.M. Tormyshev2,1

, M.V. Fedin

3,1, E.G. Bagryanskaya

2,3,1

1 Novosibirsk State University, 630090, Pirogova str., 2, Novosibirsk, RUSSIA.

2 N.N. Vorozhtsov Novosibirsk Institute of Organic Chemistry SB RAS, 630090, ave. Lavrentiev, 9,

Novosibirsk, RUSSIA.

3 International Tomography Center SB RAS, 630090, Institutskaya str., 3A, Novosibirsk, RUSSIA.

E-mail: [email protected].

Triarylmethyl (trityl) radicals represent a relatively new class of spin labels having

long Tm on the order of microseconds in liquids at room temperature. This profoundly

long relaxation makes trityls a promising alternative for nitroxide spin labels. Recently

we demonstrated first distance measurement of ~4.6 nm at physiological temperature

310 K (37 0C) in model DNA duplex (1). The development of this research area implies

further improvement of trityl-based labels in order to achieve longer phase memory time

Tm and identification of the factors affecting the Tm for trityl radicals at 300 K.

In this work we studied the magnetoresonance properties of mono-, di-, tris-ester

derivatives of trityl radicals by CW and pulse EPR. It was found that at room

temperature Tm depends on structure of trityl radicals, resonance frequency and solvent

polarity. We observed the reduction of Tm values with increasing of resonance

frequency (from 10 to 35 GHz) at room temperature. At the same time we found that in

frozen solution the line width of the EPR spectra at Q band 2-3 times more than at X

band. It indicates that the spin-spin relaxation for studied compounds defines by

incomplete motional averaging of g- anisotropy. It was shown that the value of g-

anisotropy is reduced by increase of the number of ether substituents and is greater in

polar solvents (H2O and CH3OH) compared with nonpolar solvent (CH2Cl2).

This work was supported by RFBR (No. 14-03-31839, 13-04-00680).

(1) Shevelev, G. Y.; Krumkacheva, O. A.; Lomzov, A. A.; Kuzhelev, A. A.;

Rogozhnikova, O. Y.; Trukhin, D. V.; Troitskaya, T. I.; Tormyshev, V. M.; Fedin, M.

V.; Pyshnyi, D. V.; Bagryanskaya, E. G. J. Am. Chem. Soc. 2014, 136, 9874.

Poster 28

69

1,2,3,5 Tetrafluorobenzene Anion Radical As Studied by

the Method of Time-Resolved Magnetic Field Effect

Gleb A. Letiagin,1,2

Irina V. Beregovaya,3 Lyudmila N. Shchegoleva,

3

Vsevolod V. Borovkov1,2

1Novosibirsk State University,Pirogova str, 2, 630090, Novosibirsk, Russia

2Voevodsky Institute of Chemical Kinetics and Combustion SB RAS, Institutskaya , 3

3N. N. Vorozhtzov Novosibirsk Institute of Organic Chemistry SB RAS, pr. Lavrentieva 9


Fluorescence response of organic solutions to an ionizing irradiation bears the

imprint of the precursors of fluorescing states. These are radical ions formed by

irradiation as spin correlated geminate cation/anion pairs. Time-resolved detection of

the fluorescence intensity, I(t), allows monitoring of the ion pair recombination while

the evolution of the spin state of the geminate pairs can be extracted from the ratio

IB(t)/I0(t). Here symbols B, 0 denote the presence of high or zero external magnetic

field, respectively. This ratio, so called Time-Resolved Magnetic Field Effect (TR

MFE), exhibits peculiarities, whose temporal behavior is determined by interactions of

unpaired electron spin in the geminate radical ions. In particular, the TR MFE method is

sensitive to hyperfine coupling (HFC) constants of magnetic nucleus in the radicals thus

allowing identification of these short-lived particles at nanosecond time scale.

In this work, the TR MFE method

has been applied to study 1,2,3,5-

tetrafluorobenzene radical anion (RA)

in nonpolar solution. As shown by

DFT quantum chemical calculations,

the potential energy surface of the RA

is the surface of pseudorotation, in

which local minima are separated by

low barriers. The motion along the

pseudorotation path effectively

averages HFC constants with fluorine

nuclei to 15 mT for F1 and F3, 14 mT

for F2, and 1.4 mT for F5.

In the figure, typical experimental TR MFE curve obtained in the experiment with

irradiated solution of ~10 mM 1,2,3,5-tetrafluorobenzene in isooctane is presented

(noisy line). It is compared with the calculated TR MFE curve (bold line). To calculate

this we have taken into account only HFC with F1, F2, F3 in the radical anion while the

counterion, solvent radical cation, was treated quasiclassically.

Positions of the peculiarities in the calculated TR MFE curve (about 0.5 ns and

2.5 ns) qualitatively agree with the experimental TR MFE curve. Possibly, the

difference in the amplitude of the peculiarities partially could be explained by the effect

of relatively wide instrumental response function (FWHM of about 1 ns).

Therefore, we conclude that comparison of the experimental results and

calculations approve that radical anion of 1,2,3,5 tetrafluorobenzene is observed in the

solution for the first time.


Poster 29

70

Charge Recombination in Р3НТ/РС70ВМ Composite

Studied by Light-Induced EPR

E.A. Lukina1,2

, M.N. Uvarov2 and L.V. Kulik

1,2

1 Novosibirsk State University, Pirogova 2, 630090, Novosibirsk, Russia

2 Institute of Chemical Kinetics and Combustion, Institutskaya 3, 630090, Novosibirsk, Russia


Composites of conducting polymers and fullerene derivatives attract attention of

many researchers as a promising material for active layer of organic solar cells. Free

charge carriers are formed in such composites under the light illumination. Their

recombination is one of the main processes limiting power conversion efficiency of

organic photovoltaic devices; therefore numerous works are devoted to its mechanism

determination. It is known, that recombination in widely studied composite of

conducting polythiophene Р3НТ and soluble fullerene derivative РС60ВМ is complex

and can not be described by bimolecular Langevin model.

In this work a composite of P3HT and other fullerene derivative РС70ВМ was

studied by light-induced EPR (LEPR). In contrast to Р3НТ/РС60ВМ composite, LEPR

signal in Р3НТ/РС70ВМ can be detected in a wide temperature range up to room

temperature. This signal was attributed to free charge carriers Р3НТ+ and РС70ВМ

–. The

dependence of the intensity of LEPR signal on light intensity and the decay of LEPR

signal upon switching light off are interpreted in frame of trap-limited bimolecular

recombination model with finite rate of back electron transfer kr in [P3HT+/РС70ВМ

–]

encounter complex formed at polymer-fullerene interface during recombination

reaction. The effective recombination order was found to be close to p = 3.5 for the

temperature range from 100 K to room temperature. For temperatures above 150 K

Arrhenius behavior of effective recombination rate constant was obtained with the

activation energy Ea=0.16±0.01 eV, which is larger than analogous values for

Р3НТ/РС60ВМ reported previously (Ea=0.09 eV [1]). The difference of the observed

activation energy of bimolecular recombination in Р3НТ/РС60ВМ and Р3НТ/РС70ВМ

composites is supposed to originate from the difference of kr for the encounter

complexes [P3HT+/РС60ВМ

–] and [P3HT

+/РС70ВМ

–], which can be caused by different

geometries of the encounter complexes: РС70ВМ molecule is larger than РС60ВМ and

hence larger distortion of P3HT chains is expected for Р3НТ/РС70ВМ interphase. The

weak temperature dependence of k0(T) at temperatures below 125 K was explained by

contribution of another recombination channel, namely, tunneling of charge carriers.

The work was supported by RFBR grant №12-03-00238-a, by project of Presidium

of RAS № 23/24.48 “Nanodynamics of disordered media” and by Scholarship of the

President of Russian Federation SP-3596.2013.1.

[1] H. Tanaka, Y. Yokoi, N. Hasegawa et al. J. Appl. Phys. 2010, 107, 083708

Poster 30

71

. The study of redox reactions involving anticancer

quinone-chelator in the presence of metal ions.

I.D. Markova, O.Yu. Selutina, K.Yu. Fedotov, L.G. Fedenok, N.E. Polyakov, L.M.

Weiner*

Institute of Chemical Kinetics and Combustion, 630090, Institutskaya 3,

Novosibirsk, Russia;

*Weizmann Institute of Science, Rehovot, 76100, Israel.

e.mail: [email protected]

Currently, elucidation of the mechanisms of

drug activity at the molecular level and finding ways

to increase their efficiency is an important scientific

problem. At the present work quinone which can

form complexes with various metal ions: (2-phenyl-

4-(butylamino)naphtho[2,3-h] quinoline-7,12-dione)

has been synthesized to study the effect of chelation of metal ions on the generation of

free radicals by quinone in photoinduced processes. The anticancer activity of this

compound was demonstrated earlier [1]. The purpose of the present work is to figure

out how the binding with the metal ion affects the ability of the quinone to generate free

radicals. We tried to investigate this question by using the NMR and CIDNP

(chemically induced dynamic nuclear polarization) techniques.

The chelate complex formation of this quinone with the metal ions (Fe 2+

, Ca2+

and Zn2+

) was proved using the optical absorption method. It was demonstrated that

binding with metal ions results in significant changes in absorption spectrum of

quinone. The stoichiometry of chelate complexes are 1:1 with Zn ions, and 2:1 with Fe

and Ca ions. The stability constants and extinction coefficients of all complexes were

calculated.

To study the influence of metal binding on the efficiency of the generation of

free radicals by NMR and CIDNP techniques, the photoinduced oxidation of NADH

and its synthetic analog, 2,6-dimethyl-3,5-dicarbomethoxy-1,4-dihydropyridine (DHP)

by quinone was investigated in the presence of Zn and Ca ions. The significant increase

of polarization intensity and the yield of reaction products after photolysis was observed

in the presence of metal ions. Increase in the CIDNP intensity and the yield of reaction

product allows one to suggest that the reactivity of the quinone increased in the presence

of metal ions. Taking into account that the free radicals production is the key step of

anticancer activity of this quinone, the present results indicate the perspectives of its

practical application.

[1] S.I. Dikalov, G.V. Rumyantseva, A.V. Piskunov, and L.M. Weiner, Role of

Quinone-Iron(III) Interaction in NADPH-Dependent Enzymatic Generation of

Hydroxyl Radicals. Biochemistry (1992), 31, 8947-8953.


Poster 31

72

New Spin-Labelled Photochromic System

2Andrei V. Tarataiko,

1Anna G. Matveeva,

2Denis A. Komarov,

1Victor F.

Plyusnin, 2Vladimir A. Reznikov

1Voevodsky Institute of Chemical Kinetics and Combustion SB RAS, Institutskaya, 3,

630090, Novosibirsk, Russia; 2N.N.Vorozhtsov Novosibirsk Institute of Organic Chemistry

SB RAS, pr. Lavrentieva, 9, 630090, Novosibirsk, Russia


We have synthesized a series of new members of the class of spin-labeled

photochromic systems - benzopyranes and naphthopyranes whose spin label

incorporated directly in the "nitrogen" heterocycle, and located maximally close to the

photochromic system compared to existing analogues [1].

As expected, the synthesized compounds have typical for all spiropyranes

photochromic activity (quantum yield of «spyropyran-merocyanine» photoconversion is

equal to 0.3%), and have typical for all merocyanines pH sensitivity (pKa = 2.9).

However, a close relative positioning of functional fragments firstly allowed us to

observe the processes in this photochromic system through the changes of EPR spectra

of the spin label. Note that in previous studies [1] of spin-labeled derivatives of

spyropyranes during the photoconvertion one can observe changes only macroscopic

magnetic susceptibility of the solid phase.

[1] Kaneko, T., T. Amano, H. Akutsu, J. Yamada and S. Nakatsuji (2003) Photochromic

radical compounds based on a naphthopyran systems. Org. Lett. 5, 2127–2129

Poster 32

73

Quadrupolar Magic Angle Spinning NMR Spectra Fitted

Using the Pearson IV Function

Roman M. Mironenko, Olga B. Belskaya, Valentin P. Talsi

Institute of Hydrocarbons Processing, Siberian Branch of Russian Academy of Sciences,

Neftezavodskaya st., 54, 644040, Omsk, Russia


Solid-state NMR spectroscopy is a powerful tool allowing to provide information

about the structure of materials. Important structural information contained in the NMR

spectrum can be extracted by decomposition of spectral contour into components.

Presently, an analysis of quadrupolar solid-state NMR spectra from disordered materials

is often made using the Czjzek model [1] describing the distribution in quadrupolar

interaction parameters, which can be estimated by application of averaging technique

(MQMAS). But it is not always needed to know the parameters of internal interactions;

it is only required to fast estimate the integral intensities of lines attributed to different

structural units (as in the case of routine studies of solid catalysts).

In the present work, the possibility of application of the Pearson IV function [2] for

analysis of asymmetric 27

Al MAS NMR spectra of alumina based catalysts is

demonstrated. The study was carried out using high-purity -Al2O3 and the samples of

ZnAlOx with different Zn/Al molar ratio (2.0, 3.0 and 4.0). The 27

Al MAS NMR spectra

were recorded at room temperature and a Larmor frequency of 104 MHz on a Bruker

Аvance-400 spectrometer. The fitting of spectral contours was carried out by variation

of parameters of the Pearson IV distribution. Convergence of experimental and

simulated spectrum was achieved by numerical minimization of chi-square.

As a result of fitting, a high convergence (r2 is no less than 0.997) between

experimental and simulated spectra was achieved. According to the analysis of the

spectrum of -Al2O3, about 70 % of Al atoms are in octahedral oxygen environment

(chemical shift at 11 ppm), about 30 % – in tetrahedral (68 ppm) and less than 1 % – in

pentahedral (37 ppm). This result agrees with published data [3]. The decomposition of

the 27

Al MAS NMR spectra of ZnAl mixed oxides with different Zn/Al molar ratio

revealed an increased fraction (6-9 %) of pentacoordinated Al atoms in these oxides as

compared to -Al2O3. As the Zn/Al ratio is raised, the fraction of [AlO6] octahedral

units decreases, while the fraction of [AlO4] tetrahedra increases.

References:

[1] J.-B. d’Espinose de Lacaillerie et al., J. Magn. Reson. 192 (2008) 244-251. [2]

W.P. Elderton, Frequency Curves and Correlation, Cambridge University Press,

London, 2011. [3] C. Pecharromán et al., J. Phys. Chem. B 103 (1999) 6160-6170


Poster 33

74

Interatomic Interactions and NMR of [Cp*3M3Se2]2+

M = Rh, Ir

Irina V. Mirzaeva

Nikolaev Institute of Inorganic Chemistry SB RAS, Ave. Akad. Lavrentiev, 3, 630090,

Novosibirsk, Russia


NMR of transition metal complex and cluster compounds may give lots of

measurable parameters for interpretation. Unfortunately, today in this area there are no

well established structure-property relations. Two complex cations [Cp*3M3Se2]2+

M =

Rh, Ir[1,2] have almost identical geometrical structures. Nevertheless, NMR shifts for 77

Se (1683 ppm for [Cp*3Rh3Se2]2+

and 943 ppm for [Cp*3Ir3Se2]2+

) are noticeably

different. Here, we try to find if this difference is associated rather with the relativistic

effects (which should give greater impact for the Ir cation) or with the bonding structure

of the cations. Although calculated without Spin-Orbit relativistic effects, 77

Se NMR

shifts are close to experimental values (1849 ppm for [Cp*3Rh3Se2]2+

and 1131 ppm for

[Cp*3Ir3Se2]2+

), while topological analysis of electron density of [Cp*3M3Se2]2+

M =

Rh, Ir shows the presence of M-M bonds for the Ir complex and the absence of such

bonds for the Rh complex. Therefor, we consider the change in the bonding structure to

be responsible for the difference in 77

Se NMR of the two cations.

DFT calculations were performed in ADF program suit[3] using TZP basis and

BP86 functional. To account for relativistic effects, zeroth-order regular approximation

was used. NMR parameters were calculated with GIAO method. To characterize

interatomic interactions, the topological analysis of electron density and Electron

Localization Function (ELF) was performed within DGrid-4.6[4].

This work was supported by RFBR grant 14-03-31333. The author is also grateful

to Dr. Abramov P.A. for providing the author with such interesting research objects.

1. Abramov, P. A.; Sokolov, M. N.; Mirzaeva, I. V.; Moroz, N. K. Russ. J. Coord.

Chem. 2013, 39, 379.

2. Abramov, P. A.; Zakharchuk, N.F.; Virovets, A. V.; Mirzaeva, I. V.; Sokolov, M.

N.; J. Organomet. Chem. 2014, 767, 65.

3. ADF: SCM, Vrije Universiteit, Theoretical Chemistry: Amsterdam, The

Netherlands, http://www.scm.com.

4. Kohout, M. DGrid 4.6, Radebeul, http://www.cpfs.mpg.de/~kohout/dgrid.html

Poster 34

75

Huge Spin-Orbit Relativistic Effects in NMR of Bimetallic

Rh-Sn3 and Ir-Sn3 Complexes

Irina V. Mirzaeva

Nikolaev Institute of Inorganic Chemistry SB RAS, Ave. Akad. Lavrentiev, 3, 630090,

Novosibirsk, Russia


In this work, we study two complex anions [Cp*M(SnCl3)3]– M = Rh, Ir[1] that

have almost identical geometrical and bonding (according to electron density, Electron

Localization Function (ELF), and MO analysis) structures. Nevertheless, NMR shifts

for 119

Sn nuclei are noticeably different (19 ppm for [Cp*Rh(SnCl3)3]– and –307 ppm

for [Cp*Ir(SnCl3)3]–). Calculated with only scalar relativistic effects,

119Sn NMR shifts

are close to each other and far from experimental values (220 ppm for [Cp*Rh(SnCl3)3]–

and 209 ppm for [Cp*Ir(SnCl3)3]–). But when we introduce Spin-Orbit relativistic

effects into the calculations, the 119

Sn NMR shifts move to 42.5 ppm for

[Cp*Rh(SnCl3)3]– and –257.5 ppm for [Cp*Ir(SnCl3)3]

–, which is much closer to

experimental data. Thus, here we observe large Spin-Orbit HALA (heavy-atom-on-

light-atom) relativistic effects, which may be explained with a great portion of 5s Sn

orbital in M–Sn bond (according to MO analysis).

DFT calculations were performed in ADF program suit[2] using TZP basis and

BP86 functional. To account for relativistic effects, zeroth-order regular approximation

was used. NMR parameters were calculated with GIAO method. To characterize

interatomic interactions, the topological analysis of electron density and ELF was

performed within DGrid-4.6[3].

This work was supported by RFBR grant 14-03-31333. The author is also grateful

to Dr. Abramov P.A. for providing the author with such interesting research objects.

1. Abramov, P. A.; Sokolov, M. N.; Mirzaeva, I. V.; Virovets, A. V. J. Organomet.

Chem. 2014, 754, 32.

2. ADF: SCM, Vrije Universiteit, Theoretical Chemistry: Amsterdam, The

Netherlands, http://www.scm.com.

3. Kohout, M. DGrid 4.6, Radebeul, http://www.cpfs.mpg.de/~kohout/dgrid.html.

http://www.cpfs.mpg.de/~kohout/dgrid.html

Poster 35

76

NMR Study on Methane Activation and Transformation

over In-modified ZSM-5 Zeolite

Ilya B. Moroz, Anton A. Gabrienko, Sergei S. Arzumanov, Alexander G. Stepanov

Boreskov Institute of Catalysis SB RAS, pr. Lavrentieva 5, 630090, Novosibirsk, Russia

[email protected]

Solid-state NMR spectroscopy is a very useful tool for detection of intermediates

forming on the surface of heterogeneous catalysts during hydrocarbon conversions. In

this work, it was applied to study on the mechanism of methane activation over the In-

modified zeolite, In/H-ZSM-5, which was considered as the promising catalyst for

methane transformation to aromatic hydrocarbons. It has been suggested that activation

of CH4 over In/H-ZSM-5 proceeds by dissociation of the C–H bond on indium cations

with the formation of the indium-hydride and the surface methoxide. However, there is

still no evidence for this “carbenium” pathway, as well as it is unclear which of the

indium cations (In+ or InO

+) are responsible for the methane transformation. Thus, our

research had the following goals: (1) to elucidate the mechanism of CH4 transformation

over this catalyst and (2) to determine which of the indium species are involved in this

reaction. For this purpose, we prepared the samples with predominant content of In+ and

InO+

cationic centers (denoted as In+/H-ZSM-5 and InO

+/H-ZSM-5, respectively) and

compared them to each other using 13

C CP/MAS NMR spectroscopy for monitoring the

surface species formed from CH4 at elevated temperatures. In addition, the kinetics of

H/D exchange between methane and Brønsted acid sites (BAS) of the In+/H-ZSM-5 and

InO+/H-ZSM-5 zeolites was investigated by

1H MAS NMR spectroscopy in situ at 453-

568 К. It was found that the rates of H/D exchange between CH4 molecules and BAS of

the InO+/H-ZSM-5 and In

+/H-ZSM-5 samples exceed that over the H-ZSM-5 zeolite

lacking indium by two and one orders of magnitude, respectively. The fact that the H/D

exchange involving the InO+/H-ZSM-5 sample is much faster with a lower activation

energy in comparison with the In+/H-ZSM-5 sample (74±6 kJ mol

-1 vs 127±27 kJ mol

-1)

indicates that not only BAS, but also InO+ cations participate in the exchange reaction

and, hence, in the methane activation. The results of the 13

C MAS NMR study

confirmed that the InO+

cations unlike the In+ ones provide the dissociative adsorption

of CH4. Contrary to the previously suggested, it proceeds with the formation of the

oxyindium-methyl, CH3–In=O species as the primary products (the “alkyl” pathway).

The secondary products of transformation of CH3–In=O species are the oxyindium-

methoxy, CH3–O–In=O, and formate species, as well as ethane and acetaldehyde.

Furthermore, it has been shown that upon ethylene adding, the CH3–O–In=O species

may react with simple aromatic hydrocarbons, which were formed from ethylene over

the InO+/H-ZSM-5 catalyst, with the formation of higher methylbenzenes.

This work was supported by RFBR (Grant Nos. 14-03-00040)

Poster 36

77

In Situ Spin Probe Studies of the Effect of Terahertz

Radiation on Proteins

Eugenia F. Nemova1, Tatyana V. Kobzeva

2

1 Institute of Laser Physics SB RAS, Lavrentyev ave., 13/3. 630090, Novosibirsk, Russia

2 Voevodsky Institute of Chemical Kinetics and Combustion SB RAS


Methods based on magnetic resonance provide powerful tools to study the effects

of terahertz radiation (THR) on biological systems. Proteins play exclusively important

part in vital functioning, so they comprise informative model to survey the biological

effects of radiation. The present study deals with the EPR investigation of the

conformational changes caused by tetrahertz radiation in albumin, a convenient

representative of globular proteins. It was shown in previous studies [1] that the

irradiation of bovine serum albumin (BSA) within the terahertz range induces changes

in the UV and IR spectra, intensity of native fluorescence and degree of BSA binding

with biologically active ligands. It was assumed that THR excites collective transitions

in BSA molecule resulting in conformational changes. Though the energy of THR is too

low to induce direct chemical transformations, it is sufficient to cause conformational

changes manifesting themselves as changes in BSA reactivity. We used a diamagnetic

dinitrone (1,4-dihydropyrazone dioxide synthesized at Vorozhtsov Novosibirsk Institute

of Organic Chemistry SB RAS) as a precursor of spin probe to be formed in the

interaction with BSA film irradiated with THR.

Dinitrone interacted with reaction centers of BSA to form a nitroxide; its EPR

spectrum was recorded. It was discovered that irradiation causes changes in EPR signal

width and intensity. Line broadening in the case of irradiated BSA sample provides

evidence of lower rotational mobility of the paramagnetic centre in comparison with

non-irradiated BSA, i.e. THR causes changes of probe localization on BSA. The

intensity of EPR signal in irradiated BSA sample is twice as high as that in non-

irradiated one. This means that irradiation simplifies the oxidation of spin probe

precursor on the reaction centers of BSA. Special attention was paid to the time after

irradiation within which the changes in BSA reactivity are conserved. Surprisingly, this

time was found to be several hours.

Structural modeling was involved to explain the observed phenomena.

Simulation results suggest that THR-induced conformational changes in alpha helix can

be responsible for changes in oxygen sorption on BSA functional centers, which in turn

affects the transformation of dinitrone into nitroxide and the mobility of the latter.

1. Cherkasova O.P., Fedorov V.I., Nemova E.F., Pogodin A.S. Optika I

Spektroskopiya, 2009, v. 107, No. 4, p.565-568.

Poster 37

78

Time resolved and magnetic field dependence CIDNP

study of mechanism of photoreaction involving radicals of

S-methylcysteine and S-methylglutathione

Mikhail S. Panov1,2

, Olga B. Morozova1, and Alexandra V. Yurkovskaya

1,2

1International Tomography Center, Institutskaya 3a, 630090, Novosibirsk, Russia



The photoreactions of sulfur-containing amino acids and oligopeptides with excited

triplet states of aromatic carbonyl compounds have drawn some attention because of the

biological importance of these substrates and the model character of these reactions for

the damage of cell components. It has been shown that the primary photochemical

process is electron-transfer quenching of the excited triplet state of the sensitizer by the

amino acid. One of the most important reactions of the radical cations is elimination of

CO2 to give α-aminoalkyl radicals, which are key intermediates with respect to the

secondary chemistry in these systems. There is the question: what is the structure of

transient radicals in this process?

To answer this question, in present study we have investigated photoreactions

between 3,3 ,4,4 -benzophenone tetracarboxylic acid (TCBP) and S-methyl-L-cysteine

(Cys(Me)), and photo oxidation of S-methylglutathione (GSMe) by exited triplets of 4-

benzophenone carboxylic acid (4-CBP). From pH dependence of CIDNP kinetics

pKa=3.2±0.5 and pKa=9.7±0.5 were determined for amino groups of Cys(Me)• and

GSMe• radicals, respectively. At pH above these values fast decarboxylation reaction

was revealed. To determine the structure of the intermediate radicals, magnetic field

dependence of CIDNP signal intensities was measured. From comparison of

experimental data with model calculations, the g-factors of radicals

g(Cys(Me)•)=2.0077±2 and g(GSMe

•)=2.0082±3 were extracted. These g-factors are

significantly lower than typical values of S-centered radicals, which indicates that spin

density delocalization incorporates light atoms such as oxygen or nitrogen. Based on

this fact, confirmed by results of quantum-chemical calculations and CIDNP pattern we

suggest five-membered ring structure with [S∴O] bond for the Cys(Me)• radical. Close

g-factor value, influence of charge of the amino group on proceeding of decarboxylation

reaction and CIDNP pattern proves ten-membered cyclic structure to GSMe• with

[S∴O] bond between thioether group and carboxylic group of glutamic acid residue, in

contrast to what has expected on the basis of analysis of transient absorption spectra [1].

Financial support by the program of RFBR (Projects No. 13-03-00437, No. 14-03-

31563, No. 14-03-00453, No. 14-03-00397), Grant No. MD-3279.2014.2 of the

President of the Russian Federation is gratefully acknowledged.

1. [1] P.Filipiak, G.L.Hug, K.Bobrowski et al. J. Phys. Chem. B, 2013, 117, 8, 2359-2368


Poster 38

79

Spin exchange effect in solutions of α-diimine radicals

Petrovskii S.K., Kuznetsova E.B., Gurinovich N.S., Saraev V.V.

Irkutsk State University, 664003, Russian Federation, Irkutsk, K. Marx str., 1


Diimine ligands have attracted substantial attention in last two decades. They are used

in plenty of catalytic systems especially for ethylene [1] and olefins [2] co- and

polymerization. One of the most important features of these ligands is the ability to

accept electrons (especially in the case of α-diimines) which leads to formation of

radical anions [3]. In our latest work we have shown [4] that in catalytic systems based

on α-diimine complexes of nickel (known as Brookhart catalysts) two types of

paramagnetic species are formed under real conditions of activation and catalysis. They

are complexes of Ni(I) with diimine ligands and radical-anions of diimine ligands bound

with Aluminium centers of cocatalyst. In the course of research of these radical anions

nature we have registered a lot of ESR spectra of diimine radical-anions bound with

different alkaline metals (Li, Na and K). It was found that Li+DAB

.- and K

+DAB

.-

complexes have normal count of lines in the spectrum, but Na+DAB

.+ one typically has

one extra line. E.g. in the case of (2,6-diisopropylphenyl)-diazabutadiene reduced by Na

in toluene we registered 8 lines in the spectrum instead of 7 lines registered when the

reduction was performed by Li or K. The fact cannot be explained by hyperfine

interaction with any nucleus in molecule. It is known that an effect of spin exchange

takes place in structured solid systems. We have applied the technique [5] described for

solid state systems for associates in solution. We have developed the technique that

allows modeling of ESR spectra in which spin exchange effect takes place. The results

of modeling have good agreement with experimental data (see the figure). These results

suggest that in some cases diimine radicals bound with Sodium exist as structured

associates in which spin exchange effect takes place. This effect has not been described

in literature for liquid systems by the present moment.

ESR spectrum of radical-anion of (2,6-diisopropylphenyl)-diazabutadiene with Sodium (a), model

spectrum with spin exchange effect (b) and model spectrum without spin exchange (c)

References:

1. Ittel S.D. et al., Chem. Rev. 2000, 100, 1169-1203

2. Gibson V.C. et al., Chem. Rev. 2003, 103, 283-315

3. Liu Y. et al., Organometallics 2008, 27, 5830–5835

4. Petrovskii S.K. et al., Russ. Chem. Bull. Int. Ed. 2013, 62, №6, 1323—1326

5. Yablokov Y.V. et al.. Moscow: Nauka, 1988, 181p.


Poster 39

80

2D NOESY/EXSY study of azide-tetrazole equilibrium of

2,4-diazidopyrimidines

Nadezhda V. Pleshkova, Elena B. Nikolaenkova, Georgy E. Sal’nikov, Victor P.

Krivopalov, Victor I. Mamatyuk.

N.N. Vorozhtsov Institute of Organic Chemistry, pr. Lavrentieva 9, 630090, Novosibirsk, Russia.


The specific nature of azaaromatic compounds having an azide group in the α-

position to the nitrogen atom is manifested as azide-tetrazole equilibrium. In the case of

2,4-diazidopyrimidines five different tautomers are possible.1 Azide-tetrazole

tautomerism is a slow process in the DNMR time scale, showing almost no temperature

dependence of NMR line widths up to 100 oC. Such complex multipath exchange

processes can be successfully studied by 2D NOESY/EXSY spectroscopy.2,3,4

For DMSO solutions of 5-methyl- and 5-methoxy-2,4-diazidopyrimidines four

forms (A, B, C, D) were found, their structures were determined by 2D 1H-

13C

correlation spectra. The kinetic parameters of the observed tautomerism were

determined by temperature dependence analysis of relative integral intensities of the

respective cross peaks and diagonal peaks in 1H-

1H NOESY/EXSY spectra.

1 V. P. Krivopalov et al. Dokl. Akad. Nauk SSSR Ser. Khim. – 1988, 300, 131

2 P. Denkova et al. Magn. Reson. Chem. – 2008, 46, 362

3 E. W. Abel et al. Journal of Magnetic Resonance. – 1986, 70, 34

4 http://nmr.nioch.nsc.ru/noekin/


http://nmr.nioch.nsc.ru/noekin/

Poster 40

81

. 19

F-MRI and 31

P-MRS in vivo visualisated theranostic with

anticancer activity

Natalya M. Antonova a,b,

, Vladimir A. Lisitskiy a,b

, Tatyana V. Popova

a,b, Olga D.

Zakharova a

, Igor V. Koptyug b,c

, Andrey E. Akulov d

, Vassily I. Kaledin d

, Tatyana S.

Godovikova a,b

aInstitute of Chemical Biology and Fundamental Medicine SB RAS, 630090, Lavrentiev prosp., 8,

Novosibirsk, Russia

bNovosibirsk State University, 630090, Pirogov av., 2,. Novosibirsk, Russia

cInternational Tomography Center SB RAS, 630090, Lavrentiev prosp, 8, Novosibirsk, Russia

dInstitute of Cytology and Genetics SB RAS, 630090, Institutskaya av.., 3a, Novosibirsk, Russia


A novel 19

F-MRI and 31

P-MRS visualisated theranostic with anticancer activity

has been designed and synthesized. The agent represents a multifunctional construct

containing a pyrimidine nucleoside antimetabolite (trifluorothymidine) and groups that

are responsible for (i) detection of the agent in the body using in vivo 31

P NMR

spectroscopy (amidophosphate group) and 19

F magnetic resonance spectroscopy and

tomography (CF3 group in the heterocyclic base); (ii) increased affinity of the agent to

tumor cells (residues of polyunsaturated fatty acid); (iii) efficient binding of the agent

with the cellular membrane and penetration into a cell (polyethyleneimine modified

with urocanic acid moieties); (iv) prolonged antitumor action of the agent (an acid-labile

imidazolide of 5-trifluoromethyl-2’-deoxyuridine-5’-monophosphate). Using in vivo

NMR spectroscopy it was shown that the theranostic agent can be detected directly in

the organisms of animals models. In vivo 31

P NMR (31

P-MRS) resulted in detection an

amidophosphate signal at ~ 12 ppm, 19

F MRI gave CF3 signal at 101 ppm. Using

MTT test the therapeutic construct was found to possess the highest cytotoxicity for the

MCF-7 cell line (IC50 = 0.43 М). The multifunctional construct containing 30 residues

of urocanic acid and 40 residues of trifluorothymidine 5’-monophosphate was tested

against the murine Krebs-II ascites carcinoma. The intraperitoneal injection of the

conjugates resulted in prolongation of the animals’ life and to the complete

disappearance of the tumor after three injections.

The work was supported by Integration grant #60 from SB RAS, by the RFBR

grant No 12-04-01454.

Poster 41

82

Electron Spin Echo of Light-Induced Spin Correlated Radical

Pairs in PCBM/P3HT Composite

Alexander A. Popov, Leonid V. Kulik

Institute of Chemical Kinetics and Combustion SB RAS, Instituskaya, 3, 630090,

Novosibirsk, Russia

Email: [email protected]

The composite of [6,6]-Phenyl C61 butyric acid methyl ester (PCBM) and poly(3-

hexylthiophene) (P3TH) is a good model material for studying processes which take place in

active layer of organic solar cells. Its electrical and optical properties are well-known. After

light absorption the charge transfer occurs in this material with quantum yield close to unity.

Short-living spin-correlated radical pairs PCBM /P3HT are formedi, which can be further

separated to free charge carriers.

In this work the spin dynamics of photoinduced radicals PCBM and P3HT was studied

by pulse EPR spectroscopy. The radicals were generated by laser flashes with 532nm

wavelength. Two-pulse sequence /2- - -echo was used to perform ESE experiment.

Computer modeling of ESE signal allows to interpret experimental data and to estimate

parameters of spin Hamiltonian of photoinduced radical pairs. For laser flash-generated radical

pairs PCBM /P3HT the temporal shape of ESE signal is quite unusual, but it is well reproduced

numerically.

Fig. 1. Comparison of experimental time-domain ESE signal (left) and its simulation (right).

Lengths of pulses are 16ns for /2 pulse and 32ns for pulse respectively, gap between pulses 400ns.

Resonant g-factor is equal to 2.0023.

The strength of exchange interaction in photoinduced radical pair PCBM /P3HT was

estimated during computer modeling of the experimental ESE signal. The average magnitude of

exchange interaction was approximately 1MHz. This value distributed normally with

distribution width approximately equal to 0.5 MHz.

The work was supported by RFBR grant №12-03-00238-a.

i Behrends, J.; Sperlich, A.; Schnegg et al. R. Direct detection of photoinduced

charge transfer complexes in polymer fullerene blends. Phys. Rev. B 2012, 85, 125206.

Poster 42

83

Possibility of application of diazaperylene derivatives as an

acceptor in organic photovoltaic cells.

Alexandr G. Popov, Mikhail N. Uvarov, Denis S. Baranov, Leonid V. Kulik

Institute of Chemical Kinetics and Combustion, Rzhanov street 3, 630090,Novosibirsk, Russian

Federation


Organic electron accepting materials are essential for the fabrication of organic

photovoltaic cells. The most mentioned materials are molecules based on fullerene

derivatives. Power conversion efficiency with this substance reached more than 8%.

However synthesis of these compounds is expensive. Alternative way to the fabrication

OPV is using conjugated small molecules. In this work diazaperylene derivatives were

investigated as an acceptor in OPV.

2,8-substituted diazaperylene was synthesized. Regioregular poly(3-

hexylthiophene) was chosen as a donor. The thin films of composites were prepared

using the method of spin-coating.

Diazaperylene derivatives intensively absorb in visible region. The energy of

HOMO/LUMO of diazaperylene derivatives was measured by cyclic voltammetry. The

values -3eV/-5,61eV for a); -3,08eV/-5,63eV for b); -3,07eV/5,57eV for c) were

founded.

Morphology of films was investigated by the atomic force microscope. The films

reveal crystals which are related to the diazaperylene derivatives. The sizes of crystals

depend on preparation conditions and lies in a sub micrometer region.

Electron transfer from donor to acceptor was studied by the method of electron

paramagnetic resonance (EPR). For photoexcitation of samples laser with wavelength

660 nm was used. Kinetics of the accumulation of the signal EPR after switching laser

on was measured. Assuming that main limiting process in growth signal EPR is

diffusion of the charges, the diffusion coefficient was evaluated.

The work was supported by RFBR grant №14-03-31183.

N

N

N

N

O

O

N

N

O

O

a) b) c)

Fig. 1. a) 2,8-diehexyl-dieazaperylene b)2,8-diebutylhydroxymethyl-

dieazaperylene c) 2,8-isopropylhydroxymethyl-dieazaperylene

Poster 43

84

Level Anti-Crossings are a Key Factor for Understanding

Magnetic Field Dependence of Hyperpolarization in SABRE

Experiments

Andrey N. Pravdivtsev,a,b

Konstantin L. Ivanov a,b

Alexandra V.

Yurkovskaya,a,b

Hans-Martin Vieth,c Mikhail S. Panov,

a,b Robert Kaptein

d

a International Tomography Center, Siberian Branch of the Russian Academy of Science,

Institutskaya 3a, Novosibirsk, 630090, Russia

b Novosibirsk State University, Pirogova 2, Novosibirsk, 630090, Russia

c Institut für Experimental Physik, Freie Universität Berlin, Arnimallee 14, Berlin, 14195,

Germany

d Utrecht University, Bijvoet Center, Padualaan 8, NL-3584 CH, Utrecht, the Netherlands


Various hyperpolarization methods are able to enhance the sensitivity of NMR and

MRI by several orders of magnitude. Important among these are Para-Hydrogen

Induced Polarization and Signal Amplification By Reversible Exchange (SABRE),

which exploit the strong nuclear alignment of para-hydrogen. Several SABRE

experiments have been reported but it was thus far not possible to account for the

experimentally observed sign and magnetic field dependence of the substrate

polarization. Here we present an analysis based on Level Anti-Crossings (LACs) that

provides a complete understanding of the SABRE effect. The field dependence of both

net and anti-phase polarization was measured for several ligands and could be well

reproduced by the theory. We also explain why the SABRE field dependence for

different ligands can be quite similar. In general, the LAC concept allows unraveling of

complex spin dynamics and is crucial for optimizing the performance of novel

hyperpolarization techniques in NMR and MRI.

The research was financially supported by the Russian Fund for Basic Research

(projects No. 13-03-00437, 14-03-00397) and grant of the President of Russian

Federation MD-3279.2014.2.

.

Poster 44

85

New approaches for production and application of

parahydrogen-induced polarization (PHIP) using

heterogeneous hydrogenations

O.G. Salnikov, K.V. Kovtunov, D.A. Barskiy, I.V. Koptyug

International Tomography Center, SB RAS, Institutskaya, 3A, 630090, Novosibirsk, Russia


Parahydrogen-induced polarization (PHIP) is a highly promising technique for

sensitivity enhancement of NMR and magnetic resonance imaging (MRI). Moreover, it

is a very useful method for the investigation of mechanisms of hydrogenation reactions.

This approach is based on the pairwise addition of two hydrogen atoms from the same

parahydrogen molecule to a double or a triple bond of a substrate molecule.

Toxicity of transition metal complexes which are usually used for production of

PHIP-hyperpolarized substances is a serious obstacle for potential biomedical

applications. Here we present a new approach for production of hyperpolarized gases by

gas-liquid biphasic hydrogenation with parahydrogen using a dissolved catalyst and

gaseous reactants. The reaction product is shown to return to the gas phase while

retaining a substantial level of nuclear spin hyperpolarization, providing a complete

separation of the hyperpolarized fluid from homogeneous catalyst.

Another promising approach is the use of heterogeneous catalysts. In this work it

was shown for the first time that PHIP effects can be successfully observed in

heterogeneous hydrogenations catalyzed by bulk metals and metal oxides. This result

confirms the existence of pairwise hydrogen addition route for both types of catalysts.

Also in this work PHIP technique was applied for studying the heterogeneous

hydrogenation of α,β-unsaturated carbonyl compounds. It was shown that hydrogen can

be added pairwise to C=C bonds of acrolein and crotonaldehyde over several supported

metal catalysts. The significant NMR signal enhancement provided by PHIP allowed to

detect by-products of different side reactions which occur on the metal surfaces.

The heterogeneously produced PHIP was also applied for kinetic studies of propene

hydrogenation over Pt/Al2O3. It was found that the reaction orders with respect to H2 are

different for the non-pairwise and the pairwise hydrogen addition. Therefore, different

types of active sites on catalyst surface are responsible for these two routes of

hydrogenation reaction.

This work was supported by the RAS (5.1.1), RFBR (14-03-00374-а, 14-03-31239-

mol-a, 12-03-00403-a, 14-03-93183 МСХ_а), SB RAS (57, 60, 61, 122), МК-

4391.2013.3

Poster 45

86

Association of lipid-lowering drugs – statins with

natural triterpene – glycyrrhizic acid.

Schlotgauer A.A., Petrova S.S., Kruppa A.I., Leshina T.V.

Institute of Chemical Kinetic and Combustion SB RAS, Institutskaya str., 3, 630090,

Novosibirsk, Russia


Supramolecular complexes of drugs are now widely used for targeted drugs

delivery to improve their solubility, bioavailability and stability. This approach is

particularly useful for poorly soluble medicine with side effects. Such compounds

include statins. Despite the fact that statins are generally accepted for treating and

preventing cardio – vascular diseases and atherosclerosis, unfortunately, they possess

several undesirable side properties. Therefore, the search and creation of new statins

with a lower daily dose, safer, is so actual. It's very important to choose the complexant.

We selected a natural compound triterpene glycoside - glycyrrhizic acid. It is known

that the use of some medications in the form of compositions with GA reduces drugs

therapeutic dose and reduce side effects. As a results of research by dynamic NMR

following results were obtained: 1) confirmed postulated in pharmacology association

of glycyrrhizic acid (GA) with statins; 2) glycyrrhizic acid associates, formed in acidic

media, include molecules of statins in the form of free acids; 3) the statin is rigidly

attached to associate and they rotate integrally. Furthermore an example of the

association effect on the reactivity of simvastatin is given.

Fig.1.Free induction decay of the atorvastatin (ATR) protons in the absence and presence of GA.

Poster 46

87

Reaction of benzene with bromine without catalyst: study of

kinetics and elucidation of product structures by NMR

Andrey V. Shernyukov, Alexander M. Genaev, George E. Salnikov,

Vyacheslav G. Shubin

N.N. Vorozhtsov Novosibirsk Institute of Organic Chemistry of Siberian Branch of

the Russian Academy of Sciences, Lavrentiev Ave. 9, 630090, Novosibirsk, Russia


Inability of benzene to be involved in non-catalytic reactions with bromine is noted

in many textbooks and looks as a dogma.

We have found that bromination of benzene with bromine occurs without any

catalyst or solvent at room temperature when a high concentration of bromine is used

(20 vol. % and more). The primary product of the substitution reaction is

bromobenzene, which is capable of further reaction to form o- and p-dibromobenzenes.

The reaction rate increases greatly with increasing the bromine concentration. Studies of

the reaction kinetics by NMR show that the order of the reaction on bromine is very

high (4.8).

Along with the products of the aromatic substitution reaction tetrabromocyclo-

hexenes and hexabromocyclohexanes are formed, the total amount of these products

does not exceed 1% relative to benzene.

From six possible isomers of tetrabromocyclohexene (Fig., left) only three were

observed in the reaction mixture (Fig., right). Their structures were determined from

NMR spectra and the results of quantum chemical calculations by riMP2/L1 method.

Poster 47

88

Investigation of Electron-Acceptor Sites on the Surface of

Sulfated Alumina Using EPR

Ekaterina I. Shuvarakova1,2

, Alexander F. Bedilo1,2

1Boreskov Institute of Catalysis SB RAS, Prospekt Lavrentieva 5, Novosibirsk 630090, Russia

2 Novosibirsk Institute of Technology, Moscow State University of Design and Technology, Krasny

Prospekt 35, Novosibirsk 630099, Russia

[email protected] Alumina is widely used in catalysis. The surface of the low-temperature Al2O3

phases is known to have both acid and base sites of different types. Electron-donor and

electron-acceptor sites can be investigated using suitable spin probes. This method is

based on using specific molecules which selectively interact with the surface sites

yielding surface paramagnetic species1,2

.

In the present work, relations between the concentrations of electron-acceptor

sites with different strength and concentrations of deposited sulfates were studied.

Recommendations on the use of spin probes for testing electron-acceptor sites with

different strength were suggested. The mechanism of the polycondensation of aromatic

probes on the surface electron-acceptor sites explaining experimental results was

proposed.

Sulfated Al2O3 samples with the different concentrations of SO3 (2, 4, 8, 12, 16

wt.%) were studied. Solutions of antracene (4×10-2

M), perylene and

hexamethylbenzene (2×10-2

M) in toluene and pure toluene were used as spin probes.

Two experimental techniques were used. In the first method changes of the

concentration of paramagnetic particles over time were monitored at room temperature.

The first measurement was carried out immediately after the activation of the sample;

the following measurements were carried out every 24 hours during the week. The

second technique included a study of the changes in the concentration of paramagnetic

particles after heating the activated samples with the probes for 18 hours at 80°C.

It was found that the concentration and the strength of electron-acceptor sites

significantly grew with an increase of the sulfate concentration. The strongest electron-

acceptor sites tested with toluene immediately after absorption were only detected with

a SO3 concentration 4% or higher. The weakest sites tested with perylene were present

on the surface of all the samples, with their concentration on 12% SO3 sample being

3×1019

g -1

.

1 A.F. Bedilo, E.I. Shuvarakova, A.A. Rybinskaya and D.A. Medvedev.: J. Phys.

Chem. C, 118, (2014). DOI: 10.1021/jp503523k.

2 A.F. Bedilo, E.I. Shuvarakova, A.M. Volodin, E.V. Ilyina, I.V. Mishakov, A.A.

Vedyagin, V.V. Chesnokov, D.S. Heroux and K.J. Klabunde.: J. Phys. Chem. C,

118, 13715-13725 (2014).

This work was supported by RFBR Grants 12-03-00905 and 13-03-12227-ofi_m

Poster 48

89

Reversible and irreversible recombination in spin chemistry

D.V. Sosnovsky, P.A. Purtov

Institute of Chemical Kinetics & Combustion, SB RAS; Novosibirsk State

University

Novosibirsk,630090, Institutskaya str.3, Russia


The spin chemistry of electron and nuclear spins behavior as well as of the

manifestation of magneto-spin interactions in chemical reactions is well developed both

experimentally and theoretically. The evolution of the spin density matrix of a radical

pair (RP) obeys the phenomenological equation (the main equation of spin chemistry)

()€ €(q) ,

2

SS S

Kt iL HQQt h

The last operator in equation characterizes a change in density matrix due to

reaction.

In the present work, the reaction operator of the main equation of spin chemistry

has been modified on the basis of an exactly solvable model. The model contains both

the reversible and irreversible transitions. For this model, expression for the reaction

operator is more complex due to the expanded basis of spin states. The reaction operator

of a phenomenological equation is a particular case of a more general approach and only

in the limiting case of the completely irreversible recombination process, these

operators coincide.

Figure show the functions of the time of system staying in the singlet state. The

probability of transition to the singlet reservoir decreases with spectrum center shifting

from resonance. As a result, the amplitude of S T oscillations increases. A decrease in

spectrum width for the matrix elements of transition causes oscillations determined by

S S (singlet reservoir) transitions which leads to the overlap of the oscillations in the

S T and S S transitions. The amplitude of the oscillations increases noticeably with

increasing shift of the spectrum center from resonance.

1. P.A. Purtov, Chem. Phys. Letters 496 (2010) 335

2. D.V. Sosnovsky, P.A. Purtov, Chem. Phys. Letters 608 (2014) 136

Poster 49

90

NMR and CIDNP Study of Phototransformation of Iron

Chelator Deferiprone in the Presence of Metal Ions

1,2Viktor A. Timoshnikov,

1,2Olga. Yu. Selyutina,

1Nikolay E. Polyakov

1Institute of Chemical Kinetics and Combustion, Institutskaya, 3, Novosibirsk, 630090 Russia;

2Novosibirsk State University, Pirogova 2, Novosibirsk, 630090, Russia


Deferiprone (L1) is an effective iron chelating drug which is widely used for the

treatment of iron overload diseases, such as thalassaemia. Moreover, L1 is supposed to

be an effective antioxidant that prevents oxidative stress and biomolecular, subcellular,

cellular, and tissue damage caused mostly by iron and copper induced free radicals

formation in vivo. There are many studies of pharmacological properties of L1, but so

far nothing was known about its photochemical activity and the structure of its radical

intermediates.

Recently it was demonstrated by CIDNP method that L1 undergoes fast

decomposition via electron transfer mechanism under direct and photosensitized UV

irradiation (< 310 nm) [1]. But no data exist on the influence of chelation on the

photochemical stability of deferiprone. Within this context the photochemistry of L1

and its chelate complexes are of chemical, biochemical, pharmacological and

toxicological importance. So, the goal of present study was to elucidate the effect of

metal ions on the photochemical behavior of L1.

The formation of chelate complexes with Zn, Ca and Al ions was proved by the

optical absorption technique. For all metals the formation of chelate complexes results

in appearance of additional long-wavelength absorption band, which greatly accelerates

the photodegradation of deferiprone when irradiated with ultraviolet light at a

wavelength of 308 nm. The mechanism of photodegradation was studied by NMR and

CIDNP techniques in the absence and in the presence of electron donors, NADH and

triptophan. The appearance of CIDNP effects for all systems is the evidence of free

radical mechanism of deferiprone photolysis. This information is particularly important

for the thousands of patients treated with L1 and other chelating drugs, since iron

overload diseases like thalassaemia are mainly distributed in the Mediterranean, Middle

East and South East Asian countries where extremely high sun light irradiation level is

present.

[1] V.A. Timoshnikov, V.K. Klimentiev, N.E. Polyakov, G.J. Kontoghiorghes,

Photoinduced Transformation of Iron Chelator Deferiprone: Possible Implications in

Drug Metabolism and Toxicity. J. Photochem. Photobiol. A: Chem., 289 (2014) 14-21


Poster 50

91

Magnetic spin phenomena in C-N2-O2 system under the

conditions of low-temperature plasma

I.A. Ushakov, E.A. Baranov, V.F. Myshkin

National Research Tomsk Polytechnic University, Institute of Physics and Technology,

Department of Applied Physics Engineering, Lenin Avenue, 30, 634050, Tomsk, Russia


It is known that electron spine resonance (ESR) leads to the isotope selectivity in

liquid-phase radical chemical reactions in the external magnetic field. The reaction

products are transformed to the other phase unlike reagents to the separation of isotopes

with magnetic and nonmagnetic nuclei. The search of new isotope effects is actual due

to permanent expansion of stable isotope application.

Plasma allows transforming the different substances to the radical form. It is shown

that chemical reactions between carbon and oxygen in the magnetic field are selective

on 12

C and 13

C isotopes [1]. At carbon oxidation in the magnetic field the oxides are

enriching on 13

C at oxygen lack. The carbon residue with 12

C excess forms the soot.

This process demand of precise control of oxygen in the plasma-forming gas at 1500-

3000 K.

The other method of carbon isotope separation is conversion into the other one-

phase-substances at hardly isotope exchange. At the same time it is necessary to

increase the rate of reaction one isotope with the first reagent and another isotope with

the second reagent.

We study the physical and chemical processes at chemical reaction in the external

magnetic field in plasma-forming mixture Ar-O2-N2. Also we estimate the isotope effect

at magnetic field change. Using the carbon valence electron angular moment precession

rate we estimate the 13

C oxidation rate change at 1 T magnetic field. The experimental

device discussed in the [1] is used.

References

[1] Isotope effects of plasma chemical carbon oxidation in a magnetic field / V. F.

Myshkin, V. A. Khan, D. A. Izhoykin, I. A. Ushakov // Natural Science. – 2013. –

Vol.5, № 1. – P. 57–61. DOI: 10.4236/ns.2013.51010

Poster 51

92

Resonance phenomena in plasma chemical reactions in C-O2

system in the magnetic field

D.A. Izhoykin, I.A. Ushakov, V.A. Neyman

National Research Tomsk Polytechnic University, Institute of Physics and Technology,

Department of Applied Physics Engineering, Lenin Avenue, 30, 634050, Tomsk, Russia


Plasma technologies are often used for etching, welding and cutting of metals. At

the moment the plasma technologies possibilities are used not fully.

Low-temperature plasma contains the significantly amount of radicals. The

chemical reaction rate defined by probability of singlet pair’s formation by valence

electron spines of radicals. In the magnetic field the magnetic moments of radical’s

unpaired electrons precess around power lines direction. Radical’s excited states differ

by g-factors that lead to different spine precession rate. We experimentally studied that

magnetic field can change the relation between plasmachemical radical reactions rates.

The difference between nuclear spines values is also lead to the change of radical

reactions rates relation. Therefore the magnetic field leads to isotope redistribution

between reagents and products as a radical processes result [1].

We experimentally studied the carbon isotopes oxidation in the magnetic field. The

high-frequency torch discharge is used for low-temperature plasma torch formation and

for atomic carbon feeding. It is established that carbon monoxide enriched by 13

C to

1,78% from natural abundance at oxygen lack and constant magnetic field 1.2 T on the

desired area of a torch.

Gas temperature decreases along plasma torch which is accompanied by C and O

collisions frequencies reduction. It is shown that at conjunction between 13

С and O

collision frequency and difference of its valence electrons spines precession rates the 13

C oxidation rate increases.

References

[1] Isotope effects of plasma chemical carbon oxidation in a magnetic field / V. F.

Myshkin, V. A. Khan, D. A. Izhoykin, I. A. Ushakov // Natural Science. – 2013. –

Vol.5, № 1. – P. 57–61. DOI: 10.4236/ns.2013.51010

Poster 52

93

Optical and Light-Induced Superparamagnetic

Properties in γ-Fe2O3 Nanoparticles Formed in PPI

Dendrimers

Valerya E. Vorobeva1, Natalia E. Domracheva

1, Matvey S. Gruzdev

2

1Kazan E.K. Zavoisky Physical-Technical Institute, Sibirsky Tract, 10/7,420029, Kazan,

Russia 2 Institute of Solution Chemistry, Akademischeskaya St. 1, 153045 Ivanovo, Russia E-mail:

[email protected]

We are presenting the joint study of the optical (fig. 1) and photoinduced

superparamagnetic properties (fig. 2) of a single-domain γ-Fe2O3 NPs formed in PPI-

dendrimer of the second generation. The optical absorption studies indicated direct

allowed transition with the band gap (4.5 eV), which is blue shift with respect to the

value of the bulk material (2.2 eV). This shift is explained by quantum size effects. The

influence of pulsed laser irradiation on the superparamagnetic properties of γ-Fe2O3 NPs

was studied by EPR spectroscopy. It has been shown that irradiation of the sample in

vacuo and cooled in zero magnetic field to 6.9 K leads to the appearance of a new EPR

signal, which decays immediately after the irradiation is stopped. The appearance and

disappearance of this new signal can be repeated many times at 6.9 K when we turn

on/turn off the laser. We suppose that the generation of conduction band electrons by

irradiation into the band gap of the γ-Fe2O3 changes the magnetic anisotropy and

superparamagnetic properties of NPs. This effect is suppressed in the sample containing

oxygen, since oxygen captures the conduction band electrons.

Fig. 1. Experimental (solid line) and

simulated (dashed line) absorption spectra.

The contributions from two components at

254 and 287 nm are indicated by symbols

pure PPI-dendrimer of the second

generation (G2) is shown in the inset.

Fig. 2. Changes in the EPR signal during

laser irradiation with a wavelength of 266

nm at 6.9 K for FC-sample held in vacuo.


Poster 53

94

Probe EPR study of the acidity of boric acid modified

γ-aluminas

Vyacheslav L. Yurpalov, Vladimir A. Drozdov, Evgeniya D. Fedorova,

Alexander V. Lavrenov

Institute of Hydrocarbon Processing SB RAS, Neftezavodskaya St., 54, 644040, Omsk,

Russia


Electron acceptor (Lewis) and proton donor (Brönsted) surface sites play essential

role in the adsorption and catalytic properties of oxide materials. Thermally activated

modified aluminas have found broad application as a catalyst support or as a catalyst

due to ability to vary its acid/base properties by the introduction of different

modification agents. It has been recently founded [1] that NiO/γ-Al2O3 - B2O3 catalysts

demonstrate high activity in ethylene oligomerization reaction. So it’s important to

determine the influence of B2O3 content on the acidity of modified supports.

The samples of γ-Al2O3•B2O3 with 1, 3, 5, 10, 15, 20, 30 % wt of B2O3 and pristine

alumina were studied by EPR spectroscopy on Bruker EMXplus X-band spectrometer

after their activation at 400-600oC using TEMPO in n-hexane or anthracene in toluene

solutions as probes.

The decomposition of TEMPO molecule on a boric acid modified γ-aluminas

indicated the appearance of proton donor sites and extinction or decreasing of accessible

Lewis acid sites. The application of anthracene molecule resulted in the formation of

aromatic radicals (g = 2.0038) after its interaction primary with proton donor (Brönsted)

sites.

The maxima concentrations of aromatic radicals (7-8•1015

m-2

, ~2•1018

g-1

) are

observed for alumina samples with 10, 15 and 20 % of B2O3. Catalysts based on these

supports (NiO/γ-Al2O3 - 15-20% B2O3) also demonstrated maximal catalytic activity in

ethylene oligomerization reaction [1]. That may deals with optimal fixing of supported

NiO or/and preferential for the process composition and distribution of surface acid

sites.

All measurements were carried out on the instrumental base of Omsk Research

Collaboration Centre SB RAS.

References 1. Lavrenov, A.V.; Buluchevskii, E.A.; Moiseenko, M.A.; Drozdov, V.A.; Arbuzov,

A.B.; Gulyaeva, T.I.; Likholobov, V.A.; Duplyakin, V.K. Kinet. Catal. 2010, 51, 3,

404–409.


Poster 54

95

Active oxidizing species of the biomimetic catalyst systems

based on dinuclear aminopyridine ferric complexes, hydrogen

peroxide and acetic acid: An EPR spectroscopic and reactivity

studies

Alexandra M. Zima, Oleg Y. Lyakin, Konstantin P. Bryliakov,

and Evgenii P. Talsi

Boreskov Institute of Catalysis, Lavrentieva Pr. 5, 630090, Novosibirsk, Russia

Novosibirsk State University, Pirogova St. 2, 630090, Novosibirsk, Russia


The development of efficient methods for catalytic oxidation of organic substrates

has become an important goal in chemical industry and pharmaceutics. One of the main

problems of the modern organic synthesis is the selective oxidation of unactivated

aliphatic C=C and C−H bonds. On the other hand, it is very important to make such

processes economic and environmentally friendly and to avoid the use of toxic or

expensive reagents.

Natural metalloenzymes catalyze oxidation of various organic substrates with 100%

regio- and stereoselectivity under mild conditions inspiring researchers to design

biomimetic catalysts (synthetic models of nonheme iron oxygenases). The systems

based on aminopyridine iron complexes and H2O2 as an oxidant were found to be one of

the best biomimetic catalyst systems in terms of activity and selectivity towards

epoxidation. Despite intensive research efforts, the nature of the active species in these

catalyst systems has still not been clearly established. The aim of this work was to study

the active species of the catalyst systems for selective olefin epoxidation based on

biomimetic ferric complexes bearing ligands with electron-donating substituents in

pyridine rings.

Herein, we report EPR spectroscopic and reactivity studies of the catalyst systems

[(L)FeIII

(μ-OH)2FeIII

(L)](CF3SO3)4/H2O2/CH3COOH in CH2Cl2/CH3CN mixture (L =

tris(3,5-dimethyl-4-methoxypyridyl-2-methyl)amine or bis(3,5-dimethyl-4-

methoxypyridylmethyl)-(S,S)-2,2 -bipyrrolidine). The obtained data show the formation

of extremely unstable and highly reactive iron-oxygen intermediates in the catalyst

systems studied. These species directly epoxidized cyclohexene even at −85 °C. Its EPR

parameters were very close to those of previously well characterized model oxoiron(V)

complex that allowed us to assign the observed intermediates to the FeV=O species.

The authors thank the Russian Foundation for Basic Research for the financial

support of this work, grant 14-03-00102.

Poster 55

96

ESR intensity evolution during storage of chemically modified

poly(vinylidene fluoride)

Natalia A. Zlobina, Vladimir E. Zhivulin, Leonid A. Pesin

Chelyabinsk State Pedagogical University, Lenin av., 69, 454080, Chelyabinsk, Russia


Poly(vinylidene fluoride) (PVDF) is a polymer material, the molecules of which

consist of a carbon chain skeleton and alternately attached two hydrogen or two fluorine

atoms to each carbon atom. Dehydrofluorination of PVDF is prospective for synthesis

of carbynoids - carbon nanostructures having predominantly chain-like atomic

arrangement. Chemical or radiative treatment cleaves the fluorine and hydrogen atoms

out of the carbon skeleton. Broken bonds resulting from this reaction lead to the

appearance of the magnetic activity of the material. They can be saturated via formation

double or triple carbon-carbon bonds within chains or linking with the molecules from

air. At deep stages of dehydrofluorination interchain crosslinking becomes possible.

The kinetics of the ESR reduction could clarify the role of each of these processes

during storage of chemically modified PVDF.

The samples have been prepared by chemical modification of PVDF films F-2M

(JSC "Plastpolymer", St. Petersburg). Dehydrofluorinating mixture consisted of a

saturated solution of KOH in ethanol and acetone. Before and after the reaction the

films were rinsed sequentially with acetone and distilled water. Thus three samples were

obtained with different chemical exposure duration (1, 3 and 15 hours). ESR spectra

were recorded using spectrometer RE-1306.

As expected, longer dehydrofluorination leads to an increase in the ESR intensity.

After the end of chemical treatment the ESR signal decreases. Experimental

dependences are well described by a sum of three first-order reactions with different

kinetic parameters. Each of these reactions corresponds to one of the ways of the broken

bonds saturation.

The study is supported by the Ministry of Education and Science of the Russian

Federation (a project No 2531 "Synthesis and properties of magnetically active layer on

the surface of a poly(vinylidene fluoride) film").

Poster 56

97

EPR study of single-molecule magnet behavior of

dysprosium(III) complexes

A. Sukhanov1, V. Voronkova

1, A. Baniodeh

2, A. K. Powell

2

1Zavoisky Physical-Technical Institute, Kazan, Russian Federation

2Karlsruhe Institute of Technology, University of Karlsruhe, Karlsruhe, Germany


Since discovery of the single-molecule magnets (SMMs) [1] they have been the

focus of extensive research. It was shown that, at low temperatures (2K) SMMs retain

magnetization over long periods. Magnetic bistability is observed in molecules that

possess a large spin ground state in addition to large Ising-type magnetic anisotropy.

This anisotropy barrier opposes the reversal of the spin at low temperature. Lanthanides

are strategic materials play a remarkable role in single-molecule magnetism thanks to

their large magnetic moments and large anisotropy.

Recently a family of isostructural {Fe2Dy2} coordination clusters which differ only

by substituent on their benzoate rings were synthesized [2]. It has been found that there

are indeed clear effects on the SMMs properties resulting from not only varying the

nature of substituent (–CN versus –Me) but also their position on the ring (para- versus

meta-) [2].

In this work, we present the EPR study of these clusters. The EPR measurements in

X- and Q-bands at low temperature (4-15K) for these clusters were carried out. It was

found that change of CN position effects on g-factor of Dy ions that probably reflects

the change of the ground state of these ions. The shape of the EPR spectrum in Q-band

changes after the compound is subjected to the effect of the external magnetic field.

This change can be described by the appearance of some ordering as it indicates that the

number of clusters with gz oriented along external magnetic field increases after the

effect of the external magnetic field. This effect was observed only for clusters with

meta-CN and para-Me substituents.

[1] Caneschi A., Gatteschi D., Sessoli R. et al.: J. Am. Chem. Soc., 113, 5873 (1991).

[2] Baniodeh A., Mereacre V., Magnani N. et al.: Chem. Commun., 49, 9666 (2013).

Acknowledgements: We are grateful to the Russian Foundation for Basic Research № 13-02-01157 for

partial financial support.

https://kias.rfbr.ru/Application.aspx?id=3112837

98

Table of Contents

Program…………………………………………………………………………………………………………………………. 4

Lectures

Theory of the pulse electron double resonance spectroscopy Kev M. Salikhov…………………………………………………………………………………………………………….. 8 Studies of structure and conformational changes of biomacromolecules and their complexes: pulse EPR techniques based on static and stochastic electron-electron dipolar interaction Maxim Yulikov………………………………………………………………………………………………………......... 9 Measurement of Hyperfine Couplings by Pulsed EPR Michael K. Bowman………………………………………………………………………………………………………. 10 Pulsed EPR of Spin-Labeled Biological Systems Sergei A. Dzuba………………………………………………………………………………………………………........ 11 Protein-DNA interaction: how do proteins find their target? Robert Kaptein………………………………………………………………………………………………………......... 12 Protein dynamics and Neuroprotection: Approaches by NMR Christian Griesinger……………………………………………………………………………………………............ 13 Nuclear Hyperpolarization and Spin Entanglement in Photoexcited Triplet States Gerd Kothe ……………………………………………………………………………………………………….............. 15 Cooperativity of Functional Hydrogen Bonds in Active Sites of Enzymes: NMR Study of Model Systems Peter M. Tolstoy………………………………………………………………………………………………………...... 16 Investigation of Structure and Surface Chemistry of Heterogeneous Catalysts employing Advanced Solid-State NMR Techniques Torsten Gutmann………………………………………………………………………………………………………..... 17 Advanced Solid State NMR Spectroscopy for Structural Characterization of Supported Catalysts Olga B.Lapina………………………………………………………………………………………………………........... 18 Spin resonance of electrons localized in Ge/Si quantum dot nanoheterostructures Anatoly V. Dvurechenskii ……………………………………………………………………………………………… 19 EPR in Solar Cell Research Jan Behrends………………………………………………………………………………………………………............ 20

99

Spin-Orbit-Coupling Based Spin Chemistry Ulrich E. Steiner………………………………………………………………………………………………………....... 21 Magnetoreception of Molecular Systems and Spin Selective Chemical Reactions Kiminori Maeda……………………………………………………………………………………………………….......

22

The role of level-anti-crossings in spin hyperpolarization Hans-Martin Vieth………………………………………………………………………………………………………... 23 Time resolved and field dependent CIDNP Alexandra V.Yurkovskaya ……………………………………………………………………………………………… 24 The study of practically important radical processes by spin chemistry methods. Tatyana V. Leshina ……………………………………………………………………………………………………….. 25 Application of NMR in Medical Research Nikolay E. Polyakov……………………………………………………………………………………………………….. 26 EPR discovery and identification of dinitrosyl iron complexes with thiol-containing ligands in living systems Anatoly F. Vanin………………………………………………………………………………………………………....... 27

Oral presentations of young scientists

FMR study of Cr1/3NbS2 helical magnet Fedor B. Mushenok………………………………………………………………………………………………………..

29

Possibilities of EPR diagnostics for monitoring the sportsmen’s state of health Alexandr I. Chushnikov……………………………………………………………………………………………......

30

Highly efficient exciplex formation in case of X-ray irradiation of non polar solutions Anatoly R. Melnikov……………………………………………………………………………………………………….

31

Exploiting Level Anti-Crossings in the rotating frame for transferring spin hyperpolarization Andrey N. Pravdivtsev……………………………………………………………………………………………………

32

Experimental and Theoretical NMR Analysis of Paramagnetic M(acac)3 (M = Cr, Mn) Coordination Compounds Kirill Levin……………………………………………………………………………………………………….................

33

The EPR Study Of Light-Induced Thermally Inaccessible Spin State In Copper-Nitroxide Based Molecular Magnet Irina Yu. Barskaya………………………………………………………………………………………………………....

34

100

Proton transfer process in C-H•••X hydrogen bonds Elena Yu. Tupikina………………………………………………………………………………………………………....

35

Investigation of some acetophenone derivatives in solution by NMR Alakbar E. Huseynzada……………………………………………………………………………………………………

36

Fluorinated homocysteine derivatives as potential molecular probes for 19F magnetic resonance spectroscopy and imaging: synthesis and characterization Alexey S. Chubarov……………………………………………………………………………………………………….. 37 2H NMR study of the rotational dynamics of terephatalate phenylenes in metal-organic frameworks CoMOF, NiMOF and ZnMOF: effect of different metal centers Alexandr E. Khudozhitkov….…………………………………………………………………………………………..

38

Influence of glycyrrhizin on cell membrane properties Olga Yu. Selyutina…………………………………………………………………………………………………….......

39

Low-field NMR Spectroscopy and Imaging Via Parahydrogen Based Hyperpolarization: Towards catalyst-free molecular contrast agents and MRI of industrial hydrogenation Danila A. Barskiy………………………………………………………………………………………………………......

40

Posters

Investigation of some alkenylphenol derivatives in solution by NMR Mircavid M. Agayev………………………………………………………………………………………….............

P1 42

Supramolecular complexes of macular carotenoids with enhanced solubility and oxidation stability. Irina E. Apanasenko……………………………………………………………………………………………………….

P2 43

Magnetic field effects in E.coli cells in the presence of the isotope Mg Elena I. Avdeeva…………………………………………………………………………………………………............

P3 44

Self-Organization Features of the Copper(II) 3 Amino 4 Ethoxycarbonylpyrazole Compound. Alexey S. Berezin………………………………………………………………………………………………..............

P4 45

The effect of chemical reaction on the spin states evolution of spin-correlated radical ion pairs Alena O. Bessmertnykh………………………………………………………………………………………………….

P5 46

The Investigation of NMR Parameters of Heptafluoroindenyl Cation Dmitriy S. Fadeev……………………………………………………………………………………………………….....

P6 47

101

Kinetics and mechanism of the reversible photoinduced oxidation of purine nucleotides in aqueous solutions. Natalya N. Fishman………………………………………………………………………………………………………..

P7 48

Photooxidation of histidine by 3,3′,4,4′-benzophenone tetracarboxylic acid in aqueous solution studied by time-resolved and field-dependent CIDNP Natalya N. Fishman………………………………………………………………………………………………………..

P8 49

Atomistic molecular dynamics simulations of cyanobiphenyl compounds Egor Gerts……………………………………………………………………………………………………...................

P9 50

Functional EPR Imaging of Isolated and Perfused Rat Hearts: Monitoring of Tissue pH and Oxygenation Artem A. Gorodetsky……………………………………………………………………………………..………………

P10 51

Proton NMR study of hydrogen site occupancy and mobility in hydrides of disordered transition metal alloys Valeriya O. Ievleva………………………………………………………………………………………….…………...

P11 52

Investigation of antimicrobial peptide alamethicin pore formation in the membrane of Bifidobacteria cell by EPR Nikolay P. Isaev ……………………………………………………………………………………………………….......

P12 53

Theory of pulsed reaction yield detected magnetic resonance Konstantin Ivanov………………………………………………………………………………………………………....

P13 54

Spin dynamics of ZnTPP in room-temperature ionic liquids studied by Time-Resolved EPR Mikhail Y. Ivanov……………………………………………………….…………………………………………………..

P14 55

Adaptation of NMR Imaging Techniques for Experimental Mapping of the Static Magnetic Field Viacheslav A. Ivanov………………………………………………………………………………………………………

P15 56

Controlled radical polymerization of styrene in the presence of nitroxides at low temperatures Beket B. Kanagatov………………………………………………………………………………………………………...

P56 57

Application of pulse EPR for investigation of lipid-cholesterol rafts in membranes Maria E. Kardash……………………………………………………………………………………………………………

P17 58

EPR Study of Electron-Acceptor Sites during Catalytic Dehydrochlorination of 1-Chlorobutane over Nanocrystalline MgO Roman M. Kenzhin…………………………………………………………………………………………………………

P18 59

102

CIDNP in Naproxen - Pyrrolidine Dyads as a Model of Drug-Enzyme Binding. Ekaterina A. Khramtsova………………………………………………………………………………………………..

P19 60

FMR of iron-containing nanocomposites of natural polysaccharides Spartak S. Khutsishvili S.S. …………………………………………………………………………………….………

P20 61

Lipid peroxidation. Bistability and bifurcation phenomena. Magnetic field effects Alexey A. Kipriyanov………………………………………………………………………………………………………

P21 62

EPR study of the hydrogen center in HPHT diamonds grown in carbonate medium Andrey Yu. Komarovskikh………………………………………………………………………………………………

P22 63

The study of influence of sugars on the mobility of phospholipid bilayer Konstantin B. Konov………………………………………………………………………………………………………

P23 64

Effect of a heavy atom on magnetic anisotropy of monobromine substituted septet trinitrene. Experimental and theoretical (ab initio and DFT) study. Denis V.Korchagin………………………………………………………………………………………………………....

P24 65

Inclusion compound of threonin with cucurbit[7]uril - supramolecular chemistry in solution Ekaterina A. Kovalenko………………………………………………………………………………………………….

P25 66

Advanced SDSL with Nitroxyl and Trityl Radicals for Distance Measurements in Nucleic Acids Olesya А. Krumkacheva………………………………………………………………………………………………….

P26 67

Development of spin labels based on triarylmethyl radicals: pulse and CW EPR study Andrey A. Kuzhelev………………………………………………………………………………………………………..

P27 68

1,2,3,5 Tetrafluorobenzene Anion Radical As Studied by the Method of Time-Resolved Magnetic Field Effect Gleb A. Letiagin………………………………………………………………………………………………………........

P28 69

Charge Recombination in Р3НТ/РС70ВМ Composite Studied by Light-Induced EPR Ekaterina A. Lukina………………………………………………………………………………………………………..

P29 70

The study of redox reactions involving anticancer quinone-chelator in the presence of metal ions. Irina D. Markova………………………………………………………………………………………………………......

P30 71

New Spin-Labelled Photochromic System Anna G. Matveeva………………………………………………………………………………………………………….

P31 72

103

Quadrupolar Magic Angle Spinning NMR Spectra Fitted Using the Pearson IV Function Roman M. Mironenko……………………………………………………………………………………………………

P32 73

Interatomic Interactions and NMR of [Cp*3M3Se2]2+ M = Rh, Ir Irina V. Mirzaeva………………………………………………………………………………………………………......

P33 74

Huge Spin-Orbit Relativistic Effects in NMR of Bimetallic Rh-Sn3 and Ir-Sn3 Complexes Irina V. Mirzaeva………………………………………………………………………………………………………......

P34 75

NMR Study on Methane Activation and Transformation over In-modified ZSM-5 Zeolite Ilya B. Moroz………………………………………………………………………………………………………............

P35 76

In Situ Spin Probe Studies of the Effect of Terahertz Radiation on Proteins Eugenia F. Nemova………………………………………………………………………………………………………..

P36 77

Time resolved and magnetic field dependence CIDNP study of mechanism of photoreaction involving radicals of S-methylcysteine and S-methylglutathione Mikhail S. Panov……………………………………………………………………………………………………….......

P37 78

Spin exchange effect in solutions of α-diimine radicals Stanislav K. Petrovskii……………………………………………………………………………………………………

P38 79

2D NOESY/EXSY study of azide-tetrazole equilibrium of 2,4-diazidopyrimidines Nadezhda V. Pleshkova………………………………………………………………………………………………….

P39 80

19F-MRI and 31P-MRS in vivo visualisated theranostic with anticancer activity Tatyana V. Popova ………………………………………………………………………………………………………..

P40 81

Electron Spin Echo of Light-Induced Spin Correlated Radical Pairs in PCBM/P3HT Composite Alexander A. Popov……………………………………………………………………………………………………….

P41 82

Possibility of application of diazaperylene derivatives as an acceptor in organic photovoltaic cells. Alexandr G. Popov………………………………………………………………………………………………………..

P42 83

Level Anti-Crossings are a Key Factor for Understanding Magnetic Field Dependence of Hyperpolarization in SABRE Experiments Andrey N. Pravdivtsev…………………………………………………………………………………………………..

P43 84

New approaches for production and application of parahydrogen-induced polarization (PHIP) using heterogeneous hydrogenations Oleg G. Salnikov………………………………………………………………………………………………………........

P44 85

104

Association of lipid-lowering drugs – statins with natural triterpene – glycyrrhizic acid. Anna A. Schlotgauer……………………………………………………………………………………………………..

P45 86

Reaction of benzene with bromine without catalyst: study of kinetics and elucidation of product structures by NMR Andrey V. Shernyukov…………………………………………………………………………………………………..

P46 87

Investigation of Electron-Acceptor Sites on the Surface of Sulfated Alumina Using EPR Ekaterina I. Shuvarakova……………………………………………………………………………………………….

P47 88

Reversible and irreversible recombination in spin chemistry Denis V. Sosnovsky……………………………………………………………………………………………………....

P48 89

NMR and CIDNP Study of Phototransformation of Iron Chelator Deferiprone in the Presence of Metal Ions Viktor A. Timoshnikov…………………………………………………………………………………………………..

P49 90

Magnetic spin phenomena in C-N2-O2 system under the conditions of low-temperature plasma Ivan A. Ushakov………………………………………………………………………………………………………........

P50 91

Resonance phenomena in plasma chemical reactions in C-O2 system in the magnetic field Ivan A. Ushakov………………………………………………………………………………………………………........

P51 92

Optical and Light-Induced Superparamagnetic Properties in γ-Fe2O3 Nanoparticles Formed in PPI Dendrimers Valerya E. Vorobeva…………………..……………………………………………………………………..............

P52 93

Probe EPR study of the acidity of boric acid modified γ-aluminas Vyacheslav L. Yurpalov……………………………………………………………………………………………………

P53 94

Active oxidizing species of the biomimetic catalyst systems based on dinuclear aminopyridine ferric complexes, hydrogen peroxide and acetic acid: An EPR spectroscopic and reactivity studies Alexandra M. Zima………………………………………………………………………………………………………....

P54 95

ESR intensity evolution during storage of chemically modified poly(vinylidene fluoride) Natalia A. Zlobina……………………………………………………………………………………………………......

P55 96

EPR study of single-molecule magnet behavior of dysprosium(III) complexes

Andrey Sukhanov……………………………………………………………………………………………………........ P56 97

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