SYNTHESIS, CHARACTERIZATION, AND PROCESSING OF NEW ELECTROACTIVE AND PHOTOACTIVE POLYESTERS DERIVED FROM OLIGOTHIOPHENES

Synthesis of various polyesters involving oligothiophene (2-5) units h as led to materials exhibiting a good processability together with tun able absorption (from 342 to 428 nm) and fluorescence (from 411 to 558 nm) properties. It has been also found that polyesters with quaterthi ophene or pentathiophene units show some electroactivity affording the formation of radical cations and dimerized radical cations, while pen tathiophene units even permit the formation of negative charge carrier s. The presence of these charge carriers increases dramatically the co nductivity to values up to 0.4 S/cm in both oxidized and reduced state s. This good electrical transport of both p-type and n-type charge car riers combined with luminescent properties and Langmuir-Blodgett proce ssability could lead to well-organized and efficient light-emitting de vices.