Synthesis, Characterization And Studies On Fluorescence Properties Of Rare Earth With Halogen-benzoic Acid And 2, 4, 6-tris-(2-pyridyl)-s-triazine

In this work,twelve kinds of single-nuclear rare-earth ternary complexes with samarium,europium,terbium and dysprosium as the central ions were syhnthesized using halogen-benzoic acid as the first ligand, 2,4,6-tris-(2-pyridyl)-s-triazine(TPTZ) for the second ligand.We also syhnthesized europium,terbium,dysprosium doped with lanthanum,yttrium, gadolinium heteronuclear of rare-earth complex.Elemental analysis,rare earth coordination titration,Inductively coupled plasma atomic emission spectrometry(ICP) measurement and differential thermal-Thermogravimetric analysis shows that the complexes have the composition of RE(P-ClBA)₃(TPTZ)·2H₂O;RE(P-BrBA)₃(TPTZ)·2H₂O;RE (P-IBA)₃(TPTZ)·2H₂O(RE=Sm,Eu,Tb,Dy);RE(P-ClBA)₃(TPTZ)·2H₂O; RE_0.5Ln_0.5(P-BrBA)₃(TPTZ)·2H₂O;RE_0.5Ln_0.5(P-IBA)₃(TPTZ)·2H₂O(RE=Eu,Tb,Dy;Ln=La,Y,Gd);The molar conductivity indicates that all the complexes are non-electrolytes;Infrared spectroscopy and nuclear magnetic resonance spectrum of hydrogen shows that the carboxyl acid halides with rare earth ions to symmetrical bidentate chelating ligand,2,4,6-tris-(2-pyridyl)-s-triazine through the three nitrogen atoms coordinate with the rare earth ions.Fluorescence and fluorescence lifetime determination shows that the fluorescent intensity and lifetime of europium complexes is stronger than terbium complexes;heteronuclear lanthanum-doped rare earth complexes is stronger than mononuclear rare earth complexes,the ligand triplet state energy level with the Eu³⁺,Tb³⁺ excited state of the lowest energy level to match better. In addition,this article further discussed the ligand and ion-doped rare earth complexes of the fluorescence properties.