Novel photoluminescent polymers containing oligothiophene and m-phenylene-1,3,4-oxadiazole moieties: Synthesis and spectroscopic and electrochemical studies

Three conjugated polymers containing oligothiophene units (from one to thre e thiophene rings) and aromatic 1,3,4-oxadiazole moieties have been success fully synthesized. The polymer structures were characterized and confirmed by H-1 and C-13 NMR, FT-IR, and elemental analysis. Thermogravimetric analy sis demonstrated that the polymers are highly thermal stable. Tunable absor ption (from 342 to 428 nm) and fluorescence (from 411 to 558 nm) properties of polymers were observed. The electrochemical investigation indicated tha t the LUMO and HOMO energy levels of the new polymers could be adjusted. It was also revealed by the electrochemical analysis that the polymers have g ood charge injection properties for both p-type and n-type charge carriers, as well as good color tunable luminescence and film-forming properties, wh ich makes them potentially useful for fabricating efficient light-emitting devices.