Abstract: The fluorescence spectra of 4-(5′-p-biphenylyl oxadiazolyl-2′-) benzyl ω-biphenylyl polymethylene carboxylate (compounds 1-4) and their corresponding model compound 2-p-methylphenyl-5-biphenylyl-1, 3,4-oxadiazole have been determined. The-intensities of fluorescence increase as the increasing of concentration at first, then the intensities of fluorescence"decrease as the increasing of concentration. This phenomenon demonstrates that these compounds can form excimer. The experimental results show that they can form not only inter-molecular excimer but also intramolecular exciplex and triple exciplex.The fluoiesoence spectra of compounds. 1~4 in the solvents of different polarity, such as toluene, dioxane, and dichloro-methane, have been determined. The results of determination show that the intramolecular exciplex and the triple exciplex are readily formed as the increasing of the solvent polarity.

Key words: Bichromophore, excimer, exciplex, solvent effect