A systematic computational study on the reactions of dimethyl sulfoxide with XO (XÂ =Â NO2, Cl, Br and I)

The reactions of dimethyl sulfoxide (DMSO) with XO (X = NO2, Cl, Br, I) have been studied at CCSD/6-311G(d,p)//B3LYP/6-311G(d,p) level. Two reaction channels have been considered: (1) the oxygen-atom transfer (OAT) from XO (X = NO2, Cl, Br, I) to DMSO and (2) the hydrogen-abstraction by XO (X = NO2, Cl, Br, I). The reaction mechanisms of DMSO with NO3, ClO and BrO are similar: the OAT channel is the dominant channel and DMSO2 is the primary product; the hydrogen-abstraction channel is not likely to be competitive with the OAT channel. The DMSO + IO reaction, because two reaction channels have the overall negative reaction activation energies and Gibbs free energies, the reaction could occur on both reaction channels. Furthermore, the formation of the stable complex may vary the yield rate of DMSO2.