Synthesis and Photophysical Properties of Europium Complexes Containing 2,5-Biaryl-1,3,4-Oxadiazole Ligand

A series of europium complexes based on 2,5-biaryl-1,3,4-oxadiazole ligands were synthesized and their luminescence properties were discussed.The results revealed that:(1) Europium complexes had a strong UV absorbance at the wavelength of 290~350 nm,and showed the characteristic PL spectrum of europium ion(613 nm);(2) The structures of ligands had a critical role influence on PL intensity of europium complexes;the maximal excited wavelength from the film of europium complexes had a blue shift of about 60 nm than that from the same europium complexes in solution.Electroluminescence studies indicated that devices using Eu(DBM)3R-OXD as guest and PVK as a host had a maximal brightness of 15 cd/m2 and the brightness of OELD depended strongly on the structures of europium complexes.Eu(DBM)3MeO-OXD had a stronger PL intensity than that of Eu(DBM)3F-OXD,and the EL intensity of Eu(DBM)3MeO-OXD was only one fourth of that of Eu(DBM)3F-OXD.The results proved that modifying the structure of ligands could optimize the luminescence properties of europium complexes.