Doctoral Dissertations

Keywords and Phrases

Chemical Defense; Decontamination; Nerve Agents; NMR Spectroscopy; Organic Synthesis; Organophosphates

Abstract

Exposure to organophosphate-based nerve agents and pesticides poses significant health and security threats to civilians, soldiers, and first responders. Despite extensive efforts to develop chemical detoxification agents for use in topical applications on exposed skin surfaces and for intravenous injections, there remains an unmet need for effective, non-hazardous decontaminating agents. The current state-of-the-art decontaminating agent, Dekon-139 (2,3-butanedione oxime, potassium salt), exhibits adverse effects when applied to the skin.

In this study, we designed and synthesized pharmaceutically relevant aminoguanidine-derived aldimines that are relatively non-toxic and substantially more effective at decontaminating nerve agents and pesticides compared to existing agents, and they act significantly faster than Dekon-139. The aminoguanidine-based catalysts, including 2,3-butanedione aminoguanidine-imine and pyridine-4-carboxaldehyde aminoguanidine-imine, achieve near-instantaneous hydrolysis of methyl paraoxon, a nerve agent simulant, at pH ≤ 10. Under these conditions, the rate of methyl paraoxon hydrolysis is considerably faster than that achieved with Dekon-139.

Using a combination of experimental techniques, including multinuclear high-field NMR, UV-vis spectroscopy, and DFT calculations, we elucidated the pH-dependent mechanisms underlying the hydrolytic degradation of the nerve agent simulants. The proposed degradation mechanism opens new avenues for the design and synthesis of effective decontamination agents, with the potential to significantly enhance the safety and security of both military and civilian populations.

Advisor(s)

Sotiriou-Leventis, Lia
Reddy, Prakash, -2024

Committee Member(s)

Choudhury, Amitava
Winiarz, Jeffrey G.
Nam, Paul Ki-souk
Frimpong, Samuel

Department(s)

Chemistry

Degree Name

Ph. D. in Chemistry

Publisher

Missouri University of Science and Technology

Publication Date

Summer 2025

Journal article titles appearing in thesis/dissertation

Paper I, found on pages 29-64, has been published in ACS Omega.

Paper II, found on Pages 65-102, has been submitted to ACS Omega.

Pagination

xvi, 200 pages

Note about bibliography

Includes_bibliographical_references_(pages 175-196)

Rights

© 2025 Emmanuel Kingsley Darkwah , All Rights Reserved

Document Type

Dissertation - Open Access

File Type

text

Language

English

Thesis Number

T 12535

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