EXCIMER EMISSION FROM DERIVATIVES OF 2-PHENYL-5-(4-BIPHENYLYL)-1,3,4-OXADIAZOLE (PBD)

The formation of excimers of 2 phenyl 5 (4 biphenylyl) 1,3,4 oxadiazole (PBD) was shown by the examination of the fluorescence spectra of concentrated solutions of derivatives of PBD in toluene. A slight increase in the amount of emission in the longer wavelength region of the spectra was observed with increasing concentration of the PBD derivatives. At high solute concentrations the amount of the excimer emission was altered by variation of the temperature of the solution. Lower temperatures increased the relative amount of longer wavelength emission (favored excimer formation) and higher temperatures decreased the relative amount of longer wavelength emission (favored disproportionation of the excimer). © 1969, American Institute of Physics. All rights reserved.