Thermodynamical viability of the reactions of DMSO with OH, O 2 and O 3 atmospheric oxidants and a test of the IB extrapolation method

Abstract

The thermochemistry of the reaction of dimethyl sulfoxide with OH, O 2 and O 3 was investigated at a highly correlated ab initio level of theory. For the OH radical, channels that lead to CH 3S(O)CH 2 + H 2O, CH 3S(O)OH + CH 3 and CH 3SO + CH 3OH products are spontaneous. All possibilities studied for the reaction with O 2 are non-spontaneous. The reaction channels with O 3 producing CH 3SO + CH 3OOO and CH 3S(O) 2CH 3 + O 2 are thermodynamically favorable. The performance of the IB method for reaction energies containing sulfur compounds was investigated, and the results show that this extrapolation is not as efficient as expected, producing results of accuracy intermediate between cc-pVTZ and cc-pVQZ levels.