Synthesis, Structrue And Luminescent Properties Of N-Ligandwith Are Earth Complexes

Using3-amino-2-pyrazinecarboxylic acid (Ampca) as the anionic ligand, three novel crystals have been synthesized. And using phenoxyacetic acid (HPOA) and2,4,6-tri-(2-pyridyl)-s-triazine (TPTZ), three novel cluster structures have been synthesized. Among them, there is one homonuclear cluster and two heternoclear clusters. Besides, the complexes with different doping ions and different ratio have been obtained with HPOA and TPTZ. All crystals and complexes are characterized by elemental analysis, rare earth coordination titrations, molar conductivity measurements, UV-vis absorption spectroscopy and IR spectroscopy, which indicates that the composition of the crystals was Eu2(TPTZ)2(POA)6·2CH3OH, EuGd (TPTZ)2(POA)6·2CH3OH, EuY(TPTZ)2(POA)6·2CH3OH,{[Eu(Hampca)2(C2O4)]·Cl·4(DMF)·6H2O}n,{[Gd2(ampca)6(H2O)5]·7H2O}n,{Tb2(ampca)4Cl2(H2O)2}n; the complexes of different doped ratio was EuxGdy (TPTZ)2(POA)6·3H2O (x:y=1:9,3:7,5:5,7:3,9:1) and EuxYy (TPTZ)2(POA)6·3H2O (x:y=1:9,3:7,5:5,7:3,9:1), respectively. The molar conductivity results show that all of the crystals and powder complexes except {[Eu(Hampca)2(C2O4)]·Cl·4(DMF)·6H2O}n are non-electrolytes. In order to deeply discuss the mechanism, the triplet energy level as following ligand HPOA, o-ClBAH, o-BrBAH, o-NO2BAH, m-NO2BAH, p-NO2BAH, Hampca and p-hydroxybenzoic acid were measured using the phosphorescence spectra. The characterization of the complexes shows that the HPOA-TPTZ-complexes behave superior luminescent properties, such as strong luminescent intensity, long emission lifetime and high quantum efficiencies. What’s more, doping with different inert rare earth element can greatly optimize the luminescent properties. Introducing appropriate doping ions may largely enhance the luminescence intensity, prolong the emission lifetime and improve the quantum efficiencies.