[Synthesis, structure characterization and, fluorescence studies of the complexes of europium with phenylglyoxylic acid, 1,10-phenanthroline and triphenyl phosphine oxide].

Three novel europium complexes, Eu-L, EuL3phen and EuL2 (TPPO)2NO3, were synthesized (HL = phenylglyoxylic, phen= 1,10-phenanthroline, and TPPO = triphenyl phosphine oxide). The complexes were characterized by elemental analysis, conductivity, IR, and 1H NMR. The IR spectra indicated that all the complexes have a larger deltaupsilon(upsilon(as) (CO2-) - upsilon(s)(CO2-) than that of NaL, and carboxylate ions in the phenylglyoxyate coordinated as unidentate ligands. And alpha-aeto also coordinated with the europium ions. In 1H NMR, the signals of hydrogens in the phenylglyoxyate shifted toward upfield, and those in phen or TPPO slightly shifted. The excitation and emission spectra were recorded at room temperature, and the excitation spectra showed that the optimum excitation wavelengths were 374.0, 358.2 and 383.4 nm, Five emission bands of the complexes due to 5D(0)-7F(0), 5D(0)-7F(1), 5D(0)-7F(2), 5D(0)-7F(3) and 5D(0)-7F(4) transitions were observed in the region of 550-720 nm (Eu-L: 577.8, 590.2, 614.0, 648.4 and 695.4 nm; EuL3phen: 578.0, 588.4, 591.6, 611.2, 617.0, 649.4, 687.6 and 698.6 nm; EuL2 (TPPO)2NO3: 577.8, 590.4, 614.6, 649.2 and 697.6 nm). The emission intensities of europium ions were obviously sensitized by TPPO.