Push-pull substituted polythiophene

A series of bithienyls substituted in their 3,3′ positions by various electron-donating (OMe, hexyl) and electron-accepting (CN) groups has been synthesized. The electropolymerization is largely determined by the electronic effects of both substituents. We will first describe the electronic requirements for the electropolymerization to take place, and use the obtained data for the realization of a conjugated polythiophene bearing alternately electron donor and acceptor groups. The electro-optical properties of these polythiophenes show that the presence of electron-donating and electron-accepting groups leads to the formation of stable and highly localized polarons, resulting from the existence of multiple potential wells along the conjugated backbone.