Fluorescence enhancement of Tb(III) complex with a new β-diketone ligand by 1,10-phenanthroline

A novel beta-diketone, 1-(3,4,5-trisbenzyloxy)benzoyl-5-benzoyl acetylacetone (TBAA), and its corresponding binary Tb(III) complex Tb(TBAA)(3)center dot 2H(2)O and ternary complex Tb(TBAA)(3)Phen with 1,10-phenanthroline (Phen) were prepared. The ligand was characterized based on elemental analysis, FT-IR, and H-1 NMR. The complexes were characterized with elemental analysis, FT-IR and thermogravimetry and derivative thermogravimetry (TG-DTG). Photoluminescence measurements indicated that the energy absorbed by the organic ligand was efficiently transferred to the central Tb3+ ions, and the complex showed intense and characteristic emissions due to the D-5(4)-> F-7(J) transitions of the central Tb3+ ions. Both complexes showed longer fluorescence lifetimes. After the introduction of the second ligand Phen group, the relative emission intensities and fluorescence lifetimes of the ternary complex Tb(TBAA)(3)Phen enhanced more obviously than that of the binary complex Tb(TBAA)(3)center dot 2H(2)O. This indicated that the presence of the ligand TBAA and the second ligand Phen could sensitize fluorescence intensities of Tb(III) ions, and the introduction of Phen group resulted in the enhancement of the fluorescence properties of the Tb(III) ternary rare earth complex.