Synthesis, characterization, DFT and photophysical studies of new class of 1,3,4-oxadiazole-isobenzofuran hybrids

Oxadiazole-based molecules are a fascinating and continuously developing area of research. These compounds show motivating luminescent properties, emitting blue to green light with high quantum efficiency depending on the substituents attached to the oxadiazole ring. New 1,3,4-oxadiazole derivatives bearing isobenzofuran moiety were designed and synthesized and their optical properties were studied. All synthesized compounds were characterized using FTIR, NMR, and mass spectrometry. The UV–visible spectroscopy, photoluminescence spectroscopy, and quantum efficiency were determined at room temperature. The structural and absorption properties of the molecules were investigated using density functional theory (DFT) calculations. The orbital picture of all the excitations involved in these transitions were identified as π->π*. The experimental data and the DFT calculated FTIR and UV–visible spectral data are in good agreement. The fluorescence spectra of molecules show emission in the range from 343-393 nm and exhibit high quantum yield.