A highly conjugated p- and n-type polythiophenoazomethine: Synthesis, spectroscopic, and electrochemical investigation

The preparation, photophysical and electrochemical characterization of a highly conjugated p-and n-type polymer, consisting thiophene units, were analyzed. The stable diaminothiophene was an ideal monomer for the synthesis of novel conjugated polyazomethines consisting uniquely of thiophene units. The novel polyazomethine was obtained by simply heating stoichiometric amounts of two monomers under reduced pressure in the presence of a catalytic amount of trifluoroacetic acid in the absence of solvent. The energy levels, the band gap and the absorption properties was decreased further with acid doping to give semiconductor-like properties to the azomethines. Spectroscopically, the acid doping resulted in a 40 nm bathochromic shift in the adsorption spectra both in solution and in thin films. The synthetically obtained polymer can yield new materials suitable for functional devices with new operating properties.