Novel 2-(naphthalen-1-yl)-5-stilbene-1,3,4-oxadiazole molecules: Synthesis, optical properties and DFT calculation

Six novel 1,3,4-oxadiazole derivatives containing naphthalene and stibene units were synthesized by Wittig–Horner reaction in good yield. Their structures were characterized by FT-IR, 1H NMR, 13C NMR and elemental analysis. The optical properties were investigated by UV–Vis absorption and fluorescence emission spectra in THF solution. Their optimized structures and the electron density distribution of HOMO and LUMO were performed by density functional theory (DFT) at the (B3LYP)/6-31G* level. The compounds exhibit blue fluorescence emission with the fluorescence quantum yield ranged from 0.05 to 0.59. The effects of substituents on the emission spectra of these compounds are interpreted. The HOMO and LUMO levels of target compounds are −5.86 to −5.64 eV and −2.79 to −2.13 eV, respectively.