Ab initio molecular orbital and density functional studies on the solvolysis of sarin and O,S-dimethyl methylphosphonothiolate, a VX-like compound.
J Org Chem
; 70(22): 8649-60, 2005 Oct 28.
Article
em En
| MEDLINE
| ID: mdl-16238293
ABSTRACT
[reaction see text] Potential energy surfaces for the alkaline hydrolysis of sarin and O,S-dimethyl methylphosphonothiolate, a VX model compound, and the perhydrolysis of the latter have been computed at the MP2/6-31+G(d)//mPW1K/MIDI! level of theory. The effect of aqueous solvation was accounted for via the integral equation formalism polarizable continuum model (IEF-PCM) at the HF/6-31+G(d) level. Excellent agreement with the experimental enthalpy of activation for alkaline hydrolysis of sarin was found. For the alkaline hydrolysis of O,S-dimethyl methylphosphonothiolate, it was found that the P-O and P-S bond cleavage processes are kinetically competitive but that the products of P-S bond cleavage are thermodynamically favored. For the perhydrolysis of O,S-dimethyl methylphosphonothiolate, it was found that P-O bond cleavage is not kinetically competitive with P-S bond cleavage. In both cases, the data support initial formation of trigonal bipyramidal intermediates and demonstrate kinetic selectivity for nucleophilic attack on the face opposite the more apicophilic methoxide ligand.
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Base de dados:
MEDLINE
Assunto principal:
Compostos Organotiofosforados
/
Sarina
Idioma:
En
Ano de publicação:
2005
Tipo de documento:
Article