Polythienobenzothiophenes, a new family of electroactive polymers: electrosynthesis, spectral characterization and modelling

Abstract

New conducting polymers, including poly[thieno[3,2-b][1]benzothiophene] (poly-TBT) and poly [6-methoxythieno[3,2-b][1]benzothiophene] (poly-MeOTBT) were electrosynthesized by anodic oxidation of the corresponding monomers in 0.1 M LiClO₄ acetonitrile solution. Poly-TBT and poly-MeOTBT electroactive films were formed on platinum electrodes and characterized spectroscopically. FT-IR studies show that both polymers present couplings occurring on the thiophene moiety and the phenyl ring, with a step-like structure. MALDI-TOF mass spectrometry indicates that poly-TBT and poly-MeOTBT films are mainly constituted of short-chain oligomers. The results of molecular orbital (MO) calculations performed on the basis of a radical-cation electropolymerization mechanism are in good agreement with our spectral data.