Comparison of bipolaron-like charge state generation in the oxidative doping of α,ω-dithienyl and α,ω-diphenyl polyenes stabilized by methoxy and methylthio substituents

Abstract

Several α,ω-dithienyl and diphenyl polyenes substituted with mesomerically interactive methylthio substituents have been synthesized by Wittig condensation. These polyenes can be oxidatively doped with SbCl5 in solution to yield stable bipolaron-like charge states. The methylthio-substituted bipolaron spectra are considerably more red-shifted in the diphenyl polyene series than the methoxy-substituted counterparts, or the methylthiothienyl series. The potential of these states for enhanced non-linear optical response is presented.