Effective degradation of Novichok nerve agents by the zirconium metal−organic framework MOF-808

Effective degradation of Novichok nerve agents by the zirconium metal−organic framework MOF-808

de Koning, M.C.
Vieiro Soares, C.
van Grol, M.
Bross, R.P.T.
Maurin, G.

2022

Novichoks are a novel class of nerve agents (also referred to as the A-series) that were employed in several poisonings over the last few years. This calls for the development of novel countermeasures that can be applied in protective concepts (e.g., protective clothing) or in decontamination methods. The Zr metal−organic framework MOF-808 has recently emerged as a promising catalyst in the hydrolysis of the V- and G-series of nerve agents as well as their simulants. In this paper, we report a detailed study of the degradation of three Novichok agents by MOF-808 in buffers with varying pH. MOF-808 is revealed to be a highly efficient and regenerable catalyst for Novichok agent hydrolysis under basic conditions. In contrast to the V- and G-series of agents, degradation of Novichoks is demonstrated to proceed in two consecutive hydrolysis steps. Initial extremely rapid P−F bond breaking is followed by MOF-catalyzed removal of the amidine group from the intermediate product. The intermediate thus acted as a competitive substrate that was rate-determining for the whole two-step degradation route. Under acidic conditions, the amidine group in Novichok A-230 is more rapidly hydrolyzed than the P−F bond, giving rise to another moderately toxic intermediate. This intermediate could in turn be efficiently hydrolyzed by MOF-808 under basic conditions. These experimental observations were corroborated by density functional theory calculations to shed light on molecular mechanisms.

Novichoks
MOF-808
DFT
Two-step hydrolysis mechanism
Degradation
Catalysts
Density functional theory
Organometallics
Protective clothing
Zirconium
Basic conditions
Bond-breaking
Metalorganic frameworks (MOFs)
Nerve agents
Zirconium metal
Hydrolysis

http://resolver.tudelft.nl/uuid:62abca58-7d51-44fe-9ab3-f295688a0e17

https://doi.org/10.1021/acsami.1c24295

963429

American Chemical Society

1944-8244

ACS Applied Materials & Interfaces, 14 (14), 9222-9230

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