Synthesis, Characterization and Studies on Fluorescence Property of Rare Earth with Azatriphenylenes Complexes

Eleven rare earth complexes were synthesized with dibenzoylmethane(HDBM),1-phenyl-3-biphenyl-1,3-dione(HPBPD) as the first ligands and 1,10-phenanthroline(phen),dipyrido [3,2-a:2′,3′-c] quinoxaline(dpq),dipyrido-[3,2-a:2′,3′-c]phenazine(dppz) as the second ligands.Their elemental analysis,TG-DTA,UV spectra,IR spectra and fluorescence spectra were measured,the results indicate that the complexes have the compositions of RE(DBM)3L and RE(PBPD)3L·1/2H2O(RE3+= Eu3+,Tb3+;L=phen,dpq,dppz).The molar conductivity shows that all the complexes are non-electrolyte.The data of IR spectra and UV spectra indicate that the azatriphenylenes through the N atoms of the phenanthroline moiety and HDBM,HPBPD through oxygen atoms coordinated with RE3+ ions,respectively.The fluorescence spectra data show that the fluorescence intensity of β-diketone Eu3+ complexes are stronger than the series of complexes of terbium.The abilities of energy transmission of phen and dpq are stronger than dppz.The luminance properties of the rare earth complexes were studied in detail.The triplet state energy of HDBM(20 700 cm-1) is higher than that of Eu3+ 5D0(17 293 cm-1) and the energy of Tb3+ 5D4(20 454 cm-1).In all the ternary complexes,Eu(Ⅲ) complexes have strong fluorescence,while the fluorescence intensity of Tb(Ⅲ) complexes is less than that of Eu(Ⅲ) complexes,which is due to the small difference between the triplet energy of HDBM and the lowest excited state energy of Tb3+.Thus it is possible that energy transfer from HDBM ligand to Eu3+ is more effective.As a high UV absorption coefficient for organic ligands,the energy transfer is effectively to the rare earth luminescent center ion,producing a characteristic emission spectrum.