Synthesis,Characterization And Fluorescence Properties Of Rare Earth Complexes With Crown Ethers And P-Phthalic Acid

Three series of fifteen solid complexes of rare earth perchloratewith crown ethers and p-phthalic acid have been synthesized andcharacterized first time in this article. Their elemental analysis, rareearth complexometry, molar conductives and TG-DTA studies indicate that the complexes have the composition of Eu2LL'2(ClO4)4 6H2O; EuRELL'2(ClO4)4 nH2O{RE=La(n=6); RE=Gd, Y(n=9)}; Tb2LL' 2(C1O4)4- 12H20; TbRELL' 2 (ClO4)4 nH20 {RE=La(n=9) ;RE=Gd, Y(n=12)} ; Tb2LL" 2(C104)4 12H20, TbGdLL" 2(Cl04)4 12H20; (EuxTb1-x) 2LL' 2C104) 4 nH20 (x=0. 1, 0. 3, 0. 5, 0. 7, 0. 9; n=12-6x). (L= respectively. In theserare earth complexes, La3+ ion and Eu3+ion coordinate with oxygen atoms of crown ethers molecules directly, but Gd3+ Tb3+ and Y3+ ions coordinate to oxygen atom of three water molecules which form hydrogen bonds with oxygen atom of crown ethers;IR spectra and molar conductives studies indicate that p-phthalic acid is bounded with RE (III) ion;Two inorganic anions ClO4- among the four ClO4- are coordinated with the rare earth ionsand the other two doesn't. Fluorescence spectra and fluorescence lifetimes show that the fluorescent intensity and lifetime of a series of terbium complexes are higher than the series of europium' s when they have the same ligands. There are better fluorescent intensity and lifetime of heteronuclear rare earth complexes than homonuclear rare earth complexes. The fluorescence emission intensity of Eu3+ ion are raised by Tb3+ in Eu3+ -Tb3+ compounds and intensity of Tb3+ ion are quenced by Eu3+ ion. The fluorescence intensity are different in heterogeneous crown rare earth coordination compounds.