Extended radical cation of diphenyl disulfide and oxidative cyclization on a pentasil zeolite: an EPR study

Abstract

Incorporation of diphenyl disulfide (1) into a pentasil zeolite (Na-ZSM5) results in the formation of the extended radical cation, 1^˙+, as well as thianthrenium radical cation (2^˙+) formed by oxidative cyclization. The stabilization of 1^˙+ on the internal surfaces of the zeolite is unprecedented because in solution it is converted spontaneously into 2^˙+. A mechanism for the conversion of 1^˙+ to 2^˙+ consistent with processes observed on the internal surfaces of the zeolite is proposed.