Synthesis And Fluorescence Properties Of Rare Earth Complexes Of Aromatic Polycarboxylic Acids

Rare earth Aromatic carboxylate complex has been reported since 1972, As valueable luminescence material the rare earth aromatic carboxylate complex has the merits of good luminescence quality, high luminescence intensity et al. In recent years much attention has been focused on the study of rare earth aromatic carboxylate complexes. The methods of synthesizing the comples have solution reaction method,gel-diffusion method,hydrothermal synthesis method,sol-gel method et al. Among these methods the crystal synthesized by hydrothermal synthesis method has the merits of higy pure,low disfigurement,low heat stress,high quality et al. So the method has been widely used to prepare single crystal. In this paper serieses complexes were synthesized by hydrothermal synthesis method and two single crystal structure was determined by X-ray diffraction. The results as follows:(1) 1,3,5-benzenetricarboxylate(H₃BTC) was used as ligand. Tb,Y(Gd) as metal ions, two serieses complexes were synthesized in this paper, they are: Tb_xY_1-xBTC·0.5H₂O, Tb_xGd_1-xBTC·0.5H₂O, The properties of these complexes were charactered by means of IR, TG, and fluorescence spectrum. The fluorescence spectrum of these complexes show that the emission intensity of the complexes can be greatly enhanced when Tb³⁺ was substituted by doped Gd3+ or Y3+, while the position of the emission peaks remain unchanged. In this paper we analysis the sensitize role of the doped rare ions, decided the best doped proportion, and compared the fluorescence intensity with different doped rare earth ion.(2) 1,3,5-benzenetricarboxylate(H3BTC) was used as ligand. Eu,Y(Gd) as metal ions, two serieses complexes were synthesized in this paper, they are: Eu_xY_1-xBTC·0.5H₂O, Eu_xGd_1-xBTC·0.5H₂O, The properties of these complexes were charactered by means of IR, TG, and fluorescence spectrum. The fluorescence spectrum of these complexes show that the emission intensity of the complexes can be greatly enhanced when Eu3+ was substituted by doped Gd³⁺ or Y³⁺, while the position of the emission peaks remain unchanged. In this paper we analysis the sensitize role of the doped rare ions, decided the best doped proportion,. and compared the fluorescence intensity with different doped rare earth ion. (3) 3,4-pyridinedicarboxylate was used as ligands, Eu(Tb) as metal ions, four complexes were synthesis, they were: Eu2(C₇H₃NO₄)₃.4H₂O(1),Eu2(C₇H₃NO₄)₃(C₁₂H₈N₂)(H₂O).H₂O(2),Tb2(C₇H₃NO₄)₃.4H₂O(3),Tb2(C₇H₃NO₄)₃(C₁₂H₈N₂)(H₂O).H₂O(4). Complexes (2) (4)were determined by X-ray diffraction. their crystal structures are triclinic, space group P1 with (2) a=7.5670(15), b=12.662(3), c=18.384(4);α=70.82(3)°,β=78.96(3)°,γ=76.02(3)°. (4) a=7.5288, b=12.6329(18), c=18.320(3);α=70.680(2)°β=79.074(2)°,γ=76.231(2)°. Eu(Tb) has two coordination environment Eu1,Eu2(Tb1,Tb2). Each metal is nine-coordinated and formed tricapped trigonal prism geometry. Eu1(Tb1) was coordinated with nine O atom , seven coming from 3,4-pyridinedicarboxylate and two coming from coordinated water. Eu2(Tb2) was coordinated with seven O atom coming from 3,4-pyridinedicarboxylate and two N atom coming from phen. The bordered metal ions are linked into one dimensional broad band chains through bridhing 3,4-pyridinecarboxylate liagands. Besides, we discussed the difference of the fluorescence property of (1) and (2); (3) and (4).