Ab initio study of 1,4-dithiin and its cation radical and dication

Abstract

The structures of 1,4-dithiin in the neutral, radical cation, and dication states have been investigated by ab initio RHF and UHF calculations with the MIDI-4 basis set. The MIDI-4 calculations predict a folded form for the neutral state, and planar forms for the cation and dication states. These structural changes caused by one- or two-electron oxidation processes are influenced by two electronic factors: one is the weak π conjugation between the sulfur and carbon atoms and the other is the σ interaction between two sulfur atoms.