Acknowledgements

References

ConclusionResults

CWA Information

Background

Abstract MethodsThe current project aims to design, synthesize and characterize metal organic frameworks (MOFs) to use in the destruction of chemical warfare agents, specifically nerve agents. The project focuses on evaluating the effectiveness of different functionalized Zr-UiO-66/67/68 MOFs on the degradation of a nerve agent mimic in the liquid and vapor phase..

The starting materials for each MOF were initially combined and heated in an oil bath for the amount of time indicated below. The MOFs were then washed multiple times with DMF and methanol and isolated by centrifugation. The MOFs were put in the oven to dry at 60°C overnight. Once dry, the MOFs were characterized using IR and NMR spectroscopy in order to determine if the structure was properly formed. The dry MOFs were now ready to be run in a variety of tests to determine how effective they were in destroying the nerve agent mimic Paraoxon in the liquid and vapor phase using 31P NMR spectroscopy.

Initial tests focused on determining whether the solid MOFs could destroy the sarin mimic when it was placed directly onto them in aqueous and non-aqueous environments. After successful tests with only the MOF and mimic interacting, the MOFs were integrated into cotton t-shirt fibers and tested. The solid MOF powders were stirred with methanol in vials. Then 1 cm x .5cm strips of t-shirt were coated in the mixture.

These strips with MOFs integrated in the fibers were tested with and without water added and with mimic being added in direct contact as well as attempting contact through the vapor phase.

Sarin blocks the acetylcholinesterase (Pac-man) receptor with the organophosphorus bond. This causes incessant muscle spasms. The MOF deactivates the nerve agent by destroying the organophosphorus bond and replacing the fluorine atom with a hydroxide.

Vapor and liquid phase Zr-UiO-68 degraded nerve agent mimic Paraoxon

•Zr-UiO-67, Zr-UiO-67-bpy less effective

•Zr-UiO-66 not effective

● NMR Above is what the Nerve Agent looks like with no degradation

•Zr-UiO-68 most effective with water addition (above)

•31P NMR: Reduction of peak at -3.8 ppm and increase of peak at 1.8 ppm shows destruction of the nerve agent mimic

Metal Organic Frameworks (MOFs) are highly porous crystalline materials formed through bonds between metal-based nodes and organic linkers with multiple coordination sites. New research suggests that MOFs containing UiO-66 with Zr and Ce metal centers are more effective in the absorption and neutralization of Chemical Warfare Agents (CWAs). Although the Geneva Convention strictly prohibits the use of chemical weapons, nerve agents have recently been used to kill thousands of civilians in the Middle East.

Triphenyl MOF UiO-68 in direct contact with water is shown to catalyze the rapid hydrolysis of the organophosphorus nerve agent, Paraoxon. Other MOF compounds tested under analogous conditions displayed negligible destruction of the nerve agent, thus showing that clusters with increased space between their metal centers are more effective in absorbing the nerve agent. While yet to integrate a non-volatile polymeric base, this MOF is projected still to work practically and efficiently in bettering personal preservation on the battlefield. Looking forward, these results will further inform the design of improved heterogeneous catalysts for the rapid hydrolysis of chemical warfare agents.

Destruction of Organophosphorus Nerve Agents Using Metal-Organic Frameworks (MOFs)

Midshipman 1/C Turner R. Morse, Midshipman 1/C Crawford M. Smith, Midshipman 1/C Michelle A. Therianos, Midshipman 1/C Madison L. Jones

Professor Craig Whitaker, Ph.D., USNA Chemistry Department

Bunge, M.A.; Davis, A.B.; West, K.N.; West, C.W.; et. al. Synthesis and

Characterization of Uio-66-NH2 Metal-Organic Framework Cotton Composite Textiles. Industrial and Engineering Chemistry Research. 2018, 57, 9151-9161.

Howarth, A.J.; Peters, A.W.; Vermeulen, N.A.; et. al. Best Practices for the Synthesis, Activation, and Characterization of Metal-Organic Frameworks. Chemistry of Materials. 2017, 29, 26-39.

Islamoglu, T.; Atilgan, A.; Moon, S.Y.; et al. Cerium (IV) vs Zirconium (IV) Based Metal-Organic Frameworks. Chemistry of Materials. 2017, 29, 2672-2675.

Mondloch, J.E.; Katz, M.J.; et. al. Destruction of Chemical Warfare Agents Using Metal-Organic Frameworks. Nature Materials. 2017, 14, 512-516.

Smith, J.D.; Konstas, K.; Lau, C.R.; et. al. Post-Synthetic Annealing: Linker Self-Exchange and Its Effect on Polymer-Metal Organic Framework Interaction. Crystal Growth and Design. 2017, 17 (8), 4384-4392.

■Defense Threat Reduction Agency (DTRA)■United States Naval Academy Chemistry Department■United States Army Edgewood Chemical■Biological Center (ECBC)

Synthesis Progression

1) Zr-UiO-66-BDC

2) Zr-UiO-66-OH/NH2

3) Zr-UiO-67

4) Zr-UiO-67-bpy

5) Zr-UiO-68

+

Activated Sarin

Deactivated Sarin