Synthesis, Characterization And Fluorescence Properties Of Schiff Base Rare Earth Complexes

In this thesis, two novel Schiff base ligands: salicylaldehyde-Ρ-aminobenzoic acid（PAPA） and1,2-diaminophenyl-N,N′-bis-（2-pyridinecarboxaldimine）（OPA） were prepared.Then, eight novel complexes were synthesized by reaction between Schiff base and four rareearth ions. All the ligands and their metal complexes had been characterized by elementalanalysis, UV-vis, IR, H1-NMR, molar conductivity, ICP and Thermogravimetric thedifferential analyzer. At first chapter, the ligand was reacted with rare earth chloride ion. Atsecond chapter, solid complexes of rare earth picrates （pic） with the ligand OPA have beensynthesized.1. The study on the fluorescence spectrum of the Ln（Ⅲ）-PAPA complex found thattriplet level of PAPA could be easily matched with lowest excited state level of Tb（Ⅲ） andDy（Ⅲ） ions, which strengthen the fluorescence of rare earth ions because of the effectiveintramolecular energy transfer occurred. Simultaneously, Under the excitation spectrum were292nm and305nm, the fluorescence intensity of Tb（Ⅲ）-PAPA and Dy（Ⅲ）-PAPA complexeswere detected. Then, the affection of heavy metal ion on the fluorescence intensity of Tb（Ⅲ）-PAPA and Dy（Ⅲ）-PAPA complexes were tested at the same excitation spectrum, and learnedthat the trivalent chromium ion was responded maximum on the fluorescence of complexes.2. In the third chapter, synthesis method of OPA and four novel complexesSm（Pic）₃-OPA, Eu（Pic）₃-OPA, Tb（Pic）₃-OPA and Dy（Pic）₃-OPA were reported. Thefluorescence properties of solutions of four complexes were investigated in detail. We foundthat triplet level of ligand could be easily matched with lowest excited state level of four rareearth picrates（pic） and these complexes showed a strong fluorescence.1,2-diaminophenyl-N,N′-bis-（2-pyridinecarboxaldimine）（OPA） was the better sensitizer inthe three ligands and may be used as time-resolved fluorommunoassay. Besides, Rare earthcomplexes were used as a fluorescent probe to detect ten kinds of heavy metal ions.