Synthesis and Properties of Fused π-Electron Donors Possessing Vinylogous 1,3-Dithiole[5]radialene Units

Abstract

Bis- and tris-fused π-electron donors containing one or two vinylogous 1,3-dithiole[5]radialene unit (7–10) were successfully synthesized. Cyclic voltammetry revealed that the first redox waves of 7–10 correspond to simultaneous four-electron or eight-electron redox processes because of significant contribution of the moieties of vinylogous 1,3-dithiole[5]radialene exhibiting a simultaneous four-electron redox. The UV–vis–NIR spectra of the oxidative species of 7–10 generated by constant voltages exhibited absorption bands attributed to (7–9)²⁺ and 10⁴⁺ with structures of dicationic 1,3-dithiole[5]radialene vinylogs.