Design and synthesis of new donor–acceptor type conjugated copolymers derived from thiophenes

A new series of donor-acceptor type poly(thiophene) derivatives (P1–P3) were synthesized starting from thiodiglycolic acid and diethyl oxalate through multistep reactions. In the final step, the polymerization was carried out using Wittig reaction. This is a good synthetic route for the preparation of any desired p- and n-type copolymers. The optical and potential charge-transporting properties of the copolymers were investigated by UV–vis, fluorescence emission spectroscopy and cyclic voltammetry. The copolymers exhibited bluish-green/green fluorescence in their thin film forms. Cyclic voltammetry experiments showed that these copolymers have low-lying LUMO energy levels ranging from −2.98 to −3.11 eV and high lying HOMO energy levels ranging from −5.45 to −5.65 eV. The optical and electrochemical studies reveal that new copolymers are new promising materials for the development of efficient polymer light emitting diodes.