Synthesis, characterization and optoelectronic investigations of bithiophene substituted 1,3,4-oxadiazole derivatives as green fluorescent materials

Abstract

A series of novel unsymmetrical bithiophene substituted oxadiazole derivatives 2(a–e) were designed and synthesised by employing palladium catalysed Suzuki cross coupling reaction. These bipolar molecules consist of bithiophene as an electron donor unit (D) and electron transporting oxadiazole as acceptor unit (A). The structural integrity of all the new compounds was confirmed by ¹H NMR, ¹³C NMR and GC-MS analysis. The photophysical and electrochemical properties have been studied in detail using UV-Vis absorption, fluorescence spectroscopy and CV measurements. All compounds emit intense green fluorescence with good quantum yields. Density functional theory computations have been carried out to understand the structure–property relationship, the computed values are found to be in good agreement with the experimental results. The results demonstrated that the novel bithiophene containing oxadiazole derivatives could play an important role in organic optoelectronics.