Theoretical study on the reaction of the ground state 1Σ + of YS + with oxygen-transfer reagent: YS ++H 2O→YO ++H 2S in the gas phase

Abstract

The reaction mechanism of the ground state 1Σ + of YS + with oxygen-transfer reagent: YS ++H 2O→YO ++H 2S in the gas phase has been proposed and investigated by ab initio methods with 6-31G ∗∗ basis set for non-metal atoms and the effective core potentials of Lanl2dz for Y. The reaction is proceeding via two steps with seven stationary points (reactants, three intermediate complexes: ( a), ( b) and ( c), two transition states: TS1 and TS2, and products) on the reaction potential surface which involved two 1,3-hydrogen-shift reactions from oxygen atom to sulfur atom via a four-center transition state, respectively. The activation energies of the two steps are 14.2 and 47.0 kcal mol −1, respectively, at MP4 (SDTQ)/6-31G ∗∗//MP2/6-31G ∗∗ level plus zero-point energy, which indicates that the second reaction step is the rate-determining step.