The Dimethylsulfide-Hydroxyl Radical Reaction. An ab Initio Study

In keeping with a 1992 gas-phase study (J. Am. Chem. Soc. 1992, 114, 7146), MP2(FULL)/6-31+G(d) ab initio calculations find no potential energy minimum for the elusive (CH 3 ) 2 S . -OH intermediate of the tropospheric reaction of dimethylsulfide (DMS) with hydroxyl radical. A dipole-dipole complex, (CH 3 ) 2 S---HO . , is found to be stabilized against dissociation to DMS and OH . by ΔH r,298 =17 SJ mol -1 , but destabilized by ΔS r,298 =68 J mol -1 K -1