Sythesis, Characterization And Studies On Fluorescence Property Of Rare Earth With 2, 4, 6-tri(2-pyridyl)-1, 3, 5-triazine Complexes

Four solid complexes of rare earth perchloride with 2,4,6-tri(2-pyridyl)-1,3,5-triazine, fifteen solid complexes of rare earth chloride and 2,4,6-tri(2-pyridyl)-1,3,5-triazine and four solid complexes of rare earth chloride with 2,4,6-tri(2-pyridyl)-1,3,5-triazine and benzoic acid, have been synthesized and characterazied. By elemental analysis, rare earth coordination titration and TG-DTA studies, the composition of the complexes were suggested as Re(TPTZ)₂·(ClO₄)₃(Re=Eu, Tb, Sm, Dy) , Re(TPTZ)Cl₃·3H₂O and Re(C₆H₅COO)₃(TPTZ).4H₂O (Re=Eu, Tb, Sm, Dy) respectively. The molar conductivity indicates, one of the inorganic anions ClO₄^- is coordinated with Re³⁺ in the complexes of Re(TPTZ)₂·(ClO₄)₃, two of the chloride anions Cl^- are coordinated with Re³⁺ in the complexes of Re(TPTZ)Cl₃·3H₂O and the complexes of Re(C₆H₅COO)₃(TPTZ).4H₂O are nonelectrolyte. IR spectra and ¹HNMR spectra show that the TPTZ through the N atoms and C₆H₅COO^- through oxygen atoms coordinate with Re³⁺ ions, respectively. Fluorescence spectra and fluor- escence lifetimes show that the fluorescent intensity and lifetime of terbium complexes are higher than the other complexes in Re(TPTZ)₂·(ClO₄)₃ complexes and Re(TPTZ)Cl₃·3H₂O complexes, it suggests that the triplet state level of TPTZ with the excited state level of Tb³⁺ match well; The fluorescent intensity and lifetime ofeuropium complex is higher than the other complexes in Re(C₆H₅COO)₃(TPTZ). 4H₂O complexes, it suggests that the triplet state level of benzoic acid with the excited state level of Eu³⁺ match well each other, the energy, which was absorbed by benzoic acid ligand, could be transferred to rare earth ions effectively. In addition, the influence of ligands and co-doped ions have also been discussed deeply. The crystal structures of Eu(C₆H₅COO)₃(TPTZ)(H₂O), [Tb(TPTZ) (H₂O)₆]·Cl₃ and [Tb_0.1Gd_0.9 (TPTZ)(H₂O)₆]·Cl₃ were successfully determined by X-ray single crystal diffraction, the crystal of Eu(C₆H₅COO)₃(TPTZ)(H₂O) is triclinic,p-1 space group andthe coordination number is 9; [Tb(TPTZ)(H₂O)₆]·Cl₃ and [Tb_0.1Gd_0.9 (TPTZ)(H₂O)₆]·Cl₃ are all monoclinic, Cc space group, coordination number is 9, respectively.