Synthesis,characterization and optical properties of rare earth complexes with sulf-heterocyclic ligand

A series of novel ternary complexes of heavy rare earths(Tb,Er,Y) with thiophene-2,5-dicarboxylic acid(H2L) and 1,10-Phenanthroline(Phen) were synthesized and characterized by elemental analysis,TG-DTA,FTIR spectra.The compositions of the complexes were confirmed to be Ln2(L)3(phen)2·4H2O(Ln=Tb,Er,Y).Observed from ultraviolet spectra,the maximum UV absobpion peaks of H2L and Phen both had a large red shift after coordination.Carboxyl of the ligand chelated with rare earth ions in chelating bidentate mode.It was also observed that Tb2(L)3(Phen)2·4H2O emits the green fluorescence under ultraviolet light at room temperature,the measured fluorescence lifetime of Tb2(L)3(phen)2·4H2O is 0.24 ms.