Theoretical study of the reactions of the 1Σ+ ground state of MS+ (M=Sc, Y, and La) with oxygen-transfer reagent MS+ + CO→ScO++CS in the gas phase

The reaction mechanisms of the (1)Sigma(+) ground state of MS+ (M = Sc, Y, and La) with oxygen-transfer reagent MS+ CO --> MO+ CS in the gas phase has been proposed and investigated by ab initio methods with the 6-31G* basis set for nonmetal atoms and the effective core potentials of Lanl2dz for the metal atoms. A carbon migration from oxygen atom to sulfur atom via a four-center transition state is involved on the reaction potential surface. The activation energies of the reactions are 34.0, 24.1, and 36.7 kcal/mol relative to their corresponding reactants and the reaction heats are 15.7, 18.6, and 18.0 kcal/mol (respectively, for M = Sc, Y, and La) at the MP4 (SDTQ)/6-31G*/ /MP2/6-31G* level plus zero-point energy, which indicates that the cationic yttrium sulfide is more favorable for this type of reaction. (C) 2003 Wiley Periodicals, Inc.