The structural, spectroscopic and thermochemical properties of two sulfur species of atmospheric interest, methanesulfinic (CH3S(O)OH, MSIA) and methanesulfonic (CH3S(O)2OH, MSA) acids, were determined at the CCSD(T)/CBS (coupled-cluster with single and double and perturbative triple excitations/complete basis set) level of theory. Two stable conformers were found to the methanesulfinic acid, and the determined average value for the enthalpy of formation (ΔHf) was -337.2 kJ mol-1. For methanesulfonic acid, the determined enthalpy of formation was 566.2 kJ mol-1. By carefully choosing of the chemical reactions and considering the existence of two MSIA conformers, this investigation reports the most accurate ΔHf values available to date for these species
dimethyl sulfide; enthalpy of formation; CCSD(T)/CBS theory
