Synthesis and electronic properties of poly(2-phenylthieno[3,4-b]thiophene): A new low band gap polymer

The synthesis of 2-phenylthieno[3,4-b]thiophene was carried out in two steps from 3,4-dibromothiophene and phenylacetylene. Electropolymerization of this monomer affords a novel low band gap (Egap) polymer that was characterized by cyclic voltammetry and electrochemistry. An Egap of ca. 0.85 eV was observed, which is among the lowest reported to date for any conductive polymer.