Theoretical investigation of the reactivity in the C-H bond activation of CH₄ by CoS⁺ in the gas phase

Abstract

The reaction of CoS⁺ with CH₄ has been studied on both quintet and triplet potential energy surfaces at the UB3LYP/6-311+G* level. All the products are formed in endothermic processes. The lowest energy path involves a formal 1,2-addition of H₃C-H across the Co⁺₋S bond to generate a CH₃CoSH⁺ insertion intermediate. This bond activation step involves spin inversion from the quintet to the triplet surface en route to the products. The crossing points have been found by means of single-point computations as a function of the structural change along the intrinsic reaction coordinate.