Quantum Calculations of VX Ammonolysis and Hydrolysis Pathways via Hydrated Lithium Nitride.

Calen J Leverant,Jeffery A Greathouse,Mark K Kinnan,Chad W Priest,Susan B Rempe

doi:10.3390/ijms22168653

Abstract

Recently, lithium nitride (Li3N) has been proposed as a chemical warfare agent (CWA) neutralization reagent for its ability to produce nucleophilic ammonia molecules and hydroxide ions in aqueous solution. Quantum chemical calculations can provide insight into the Li3N neutralization process that has been studied experimentally. Here, we calculate reaction-free energies associated with the Li3N-based neutralization of the CWA VX using quantum chemical density functional theory and ab initio methods. We find that alkaline hydrolysis is more favorable to either ammonolysis or neutral hydrolysis for initial P-S and P-O bond cleavages. Reaction-free energies of subsequent reactions are calculated to determine the full reaction pathway. Notably, products predicted from favorable reactions have been identified in previous experiments.

Highlights

Organophosphates (OPs), a class of nerve agents and pesticides, are among the most toxic of chemical warfare agents (CWAs) [1]
Enzymes used in CWA degradation are not stable and cannot be stored for long periods of time [15]
This work aims to explore the complete decontamination of VX from base hydrolysis and ammonolysis processes in the Li3N aqueous environment

Summary

Introduction

Organophosphates (OPs), a class of nerve agents and pesticides, are among the most toxic of chemical warfare agents (CWAs) [1]. The neutralization of OP compounds can be achieved through oxidation [5,6], enzyme degradation [7,8,9], hydrolysis [10,11,12], and incineration [13]. Oxidation requires large excesses of oxidizing agents and is not very selective [6,14]. Enzymes used in CWA degradation are not stable and cannot be stored for long periods of time [15]. Incineration requires that the CWAs are moved to facilities with the appropriate equipment [16], and cannot be used in many locations

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Conclusion