Synthesis, Characterization and Fluorescence of Terbium (III) Complexes with Phenylglyoxylic Acid and 2,2-Dipyridine, 1, 10-Phenanthroline, Triphenyl Phosphine Oxide

Three new complexes TbL3dipy(H2O)2, TbL3phen(H2O)2 and TbL2(TPPO)2NO3 were synthesized (L = phenylglyoxylate ion, dipy = 2, 2-dipyridine, phen = 1, 10-phenanthroline, TPPO = Triphenyl phosphine oxide). Elemental analysis, conductivity, IR spectra, and 1HNMR spectra studies were performed. IR spectra indicate that the carboxylate ion of phenylglyoxylate is coordinated to the Tb (III) ion as an unidentate ligand. In 1HNMR, the signals of different hydrogens in phenylglyoxylate ion shift upfield. The excitation and emission spectra of the three solid complexes were recorded at room temperature, in which the optimum excitation wavelengths are 361.0, 359.0 and 367.0 nm for these three complexes, respectively. Four emission bands due to the 5D4–7Fj(j = 6, 5, 4, 3) transitions were observed for TbL3dipy(H2O)2(489.0, 545.0, 584.0, 620.0 nm) and TbL3phen(H2O)2(490.0, 544.0, 583.0, 620.0 nm). Under the same conditions, only one emission band due to the 5D4–7F5 transition was observed for the complex TbL2(TP-PO)2NO3. The emission intensity of TbL3dipy(H2O)2 is the strongest among the three complexes.