Study of the Reactive Properties of a VX Model Compound as Determined by Electrostatic Potential Calculations

摘要

An ab initio self consistent field approach has been used to study the properties of an organophosphorus compound which is being taken as a model for VX (0-ethyl-S-2-disoproplaminoethyl methylphosphonothiolate). The optimize geometry was determined at the STO-3G* level, and an STO-5G basis set was then used for computing the molecular electrostatic potential. This shows major negative regions (attractive toward electrophiles) near the phosphoryl oxygen and the nitrogen, with increasingly weaker ones in the vicinity of the alkoxy oxygen and the sulfur.It is suggested that an essential factor in the anticholinesterase activity of VX may be the presence of negative potentials of appropriate magnitudes associated with the oxygens and the sulfur. Our results support earlier speculation that the presence of the nitrogen may interfere with the metal-catalyzed hydrolysis of VX. Keyword: Anticholinestrerase; organophosphorus; electrostatic potential; abinitio calculations self consistant field, VX agents; (Reprints).