Synthesis and characterization of polyesters derived from oligothiophenes.

During the past few years, pi-conjugated organic polymers, have shown interesting optical and electrical features for the preparation of light-emitting diodes. In order to develop useful polymeric materials for such electrooptical applications, we have synthesized new polyesters derived from oligothiophene units (from bithiophene to pentathiophene). By employing oligothiophenes, the conjugation length can be controlled and the emission characteristics of the chromophore can be fine-tuned. The non-emitting flexible spacers improve solubility and flexibility. With quater and penta thiophene,electroactive polyesters have been obtained although they have insulating nonconjugated segment in the main chain.