Oxidation mechanism of dimethyl sulfoxide (DMSO) by OH radical in liquid phase

Abstract

The thermodynamics of the oxidation mechanism of dimethyl sulfoxide (DMSO) by OH radical in the liquid phase was investigated at the ab initio uPMP2/6-311G(d,p) level. Three distinct approaches to describing the solvent effect in the mechanism were considered: (1) a liquid phase mechanism considering the solvent as a continuum and polarizable medium; (2) a water-assisted gas phase reaction; (3) a combination of models 1 and 2, where the clusters containing the reactants and water molecules were studied in the polarizable continuum medium. The specific interactions and the bulk solvent effects were analyzed, the changes in the thermodynamic profile relative to the gas phase mechanism were determined and the overall rate coefficient for the oxidation of DMSO was evaluated.