Department of Chemical and Biochemical Engineering, Rutgers, the State University of New Jersey, Piscataway, New Jersey 08854, United States.
J Phys Chem A. 2011 May 26;115(20):5201-9. doi: 10.1021/jp200509u. Epub 2011 May 4.
Using molecular dynamics simulations, we modeled solvation and diffusion in aqueous solutions of organophosphorous compounds, including nerve G-agents sarin and soman (methylphosphonofluoridates) and their common simulants DMMP (dimethyl methylphosphonate) and DIFP (diisopropyl fluorophosphate). The aqueous solutions of the organophosphorous compounds were found to display complex molecular scale structures and dynamic properties due to competing interactions between strongly hydrophobic and hydrophilic groups. The mixing of agents with water was proved to be exothermic with negative excess mixing volume, indicating a strongly hydrophilic solvation. This effect was confirmed in a specially performed experiment. We discuss to what extent DMMP and DIFP are suitable simulants for G-agents in experimental studies, as far as their interactions with water are concerned. We also focus on the relevance of the structural features and mobilities of agents in water to their interactions with permselective polyelectrolyte membranes that may be employed as protective barriers against chemical warfare agents.
利用分子动力学模拟，我们对有机磷化合物在水溶液中的溶解和扩散进行了建模，这些化合物包括神经毒剂沙林和梭曼（甲基膦酸氟化物），以及它们常见的模拟物 DMMP（二甲基甲基膦酸酯）和 DIFP（二异丙基氟膦）。由于强疏水性和强亲水性基团之间的竞争相互作用，有机磷化合物的水溶液显示出复杂的分子尺度结构和动态特性。事实证明，化合物与水的混合是放热的，混合体积为负，表明其具有很强的亲水性溶剂化作用。在一项特别进行的实验中证实了这一效果。我们讨论了在实验研究中，DMMP 和 DIFP 在多大程度上可以作为 G-剂的合适模拟物，就其与水的相互作用而言。我们还关注了在水中的结构特征和试剂的迁移率与可能用作化学战剂防护屏障的选择性聚电解质膜之间相互作用的相关性。
