Theoretical ab initio study of the reaction of CH3SH with OH radical

Abstract

The title reaction has been studied using high-level ab initio methods. Mechanisms of both hydrogen abstraction from the sulfur atom by OH, and addition of OH to the sulfur atom in CH₃SH have been studied. Using the additivity approximation, the results at the QClSD(T)(Full)/6–311 + G(2df,p) level are as follows: for the hydrogen abstraction, ΔH=– 103.3 kJ mol^–1, and ΔH^≠=–7.7 kJ mol^–1; for the reaction to form an adduct, ΔH= 6.0 kJ mol^–1 and ΔH^≠=–1.3 kJ mol^–1. The implications of these results for the mechanism of the reaction are discussed.