On the stability of trivalent chalcogen radicals—a pseudopotential study of homolytic substitution by a methyl radical at methanethiol, methaneselenol and methanetellurol

Abstract

Ab initio molecular orbital theory using pseudopotential basis sets and electron correlation predict that homolytic substitution by a methyl radical at sulfur and selenium proceeds via symmetrical transition states with barriers of 87.9 and 63.1 kJ mol ^–1respectively; the similar reaction at tellurium is predicted to proceed via a symmetrical intermediate which lies 23.5 kJ mol ^–1 above reactants.