Synthesis,Characterization and Fluorescence of Eu~(3+),Tb~(3+) Complexes with 2-Thiophencarboxylic Acid and 1,10-Phenanthroline

Two ternary complexes of Eu3+ and Tb3+ with 2-thiophene carboxylic acid(L)-1.10-phenanthroline and two binary complexes of 2-thiophene carboxylic acid have been synthesized.By elecmental analysis,rare earth coordination titration,molar conductivity measurement,the compositions of the complexes were suggested as REL3·2H2O and REL3L′·C2H5OH(RE=Eu,Tb,L=2-thiophene carboxylic acid,L′=1.10-phenanthroline) respectively.The ligand and coordination compounds have been studied by means of IR spectra,fluorescent excitation and emission spectra.IR spectra studies indicate that the 2-thiophene carboxylic acid ligand is bonded with RE(Ⅲ) through oxygen atoms in carboxyl group and 1.10-phenanthroline ligand is bonded with RE(Ⅲ) through nitrogen atoms.The molar conductivities in DMF solvent indicate that the complexes are nonelectrolyte.The fluoresence spectra show that the fluorescence emission intensity of ternary complexes is more intensive than that of the binary complexes.