| Abstract
| - We have performed DFT computational studies [B3LYP, 6-31+G*] to obtain metal ion coordination isomersof VX-Me [MeP(O)(OMe)(SCH2CH2NMe2)], a model of two of the most lethal nerve agents: VX [MeP(O)(OEt)(SCH2CH2N(iPr)2)] and Russian-VX [MeP(O)(OCH2CHMe2)(SCH2CH2N(Et)2)]. Our calculationsinvolved geometry optimizations of the neutral VX-Me model as well as complexes with H+, Li+, Na+, K+,Be2+, Mg2+, and Ca2+ that yielded 2−8 different stable chelation modes for each ion that involved mainlymono- and bidentate binding. Importantly, our studies revealed that the [OP,N] bidentate binding mode, longthought to be the active mode in differentiating the hydrolytic path of VX from other nerve agents, was themost stable for all ions studied here. Binding energy depended mainly on ionic size as well as charge, withbinding energies ranging from 364 kcal mol-1 for Be2+ to 33 kcal mol-1 for K+. Furthermore, calculatedNMR shifts for VX-Me correlate to experimental values of VX.
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