Absorption and Fluorescence Spectra of some 1,3,4-Oxadiazole Derivatives in n-Paraffins at 77 K

The quasilinear absorption and fluorescence spectra of 2- (1-naphthyl) -5-phenyl 1,3,4 oxadiazole, 2-(2-naphthyl)-5- phenyl 1,3,4 oxadiazole, 2-(1-naphthyl) -5-(4-biphenylyl) - 1,3,4 oxadiazole and 2-(2-naphthyl)-5-(4-biphenylyl)-1,3,4 oxadiazole have been studied in n-hexane, decane and nonane at 77 K. An analysis of the vibrational structure in the first electronic excited singlet state (S1) and in the ground state (S0) is given. Internal oscillations in the investigated molecules found from the quasilinear spectra are in agreement with those found in the infrared spectra.