Intramolecular Energy Transfer and Co-luminescence Effect in Rare Earth Ions (La, Y, Gd and Tb) Doped with Eu3+ beta-diketone Complexes

摘要

In this paper, Eu3+ beta-diketone Complexes with the two ligands 1-(2-naphthoyl)-3, 3, 3-trifluoroacetonate (TFNB) and 2'2-bipyridine (bpy) have been synthesized. Furthermore, we reported a systematical study of the co-fluorescence effect of Eu(TFNB)(3)bpy doped with inert rare earth ions (La3+, Gd3+ and Y3+) and luminescence ion Tb3+. The co-luminescence effect can be found by studying the luminescence spectra of the doped complexes, which means that the existence of the other rare earth ions (La3+, Y3+, Gd3+ and Tb3+) can enhance the luminescence intensity of the central Eu3+, which may be due to the intramolecular energy transfer between rare earth ions and Eu3+. The efficient intramolecular energy transfer in all the complexes mainly occurs between the ligand TFNB and the central Eu3+. Full characterization and detail studies of luminescence properties of all these synthesized materials were investigated in relation to co-fluorescence effect between the central Eu3+ and other inert ions. Further investigation into the luminescence properties of all the complexes show that the characteristic luminescence of the corresponding Eu3+ through the intramolecular energy transfers from the ligand to the central Eu3+. Meantime, the differences in luminescence intensity of the D-5(0)-> F-7(2) transition, in the D-5(0) lifetimes and in the D-5(0) luminescence quantum efficiency among all the synthesized materials confirm that the doped complex Eu0.5Tb0.5(TFNB)(3)bpy exhibits higher D-5(0) luminescence quantum efficiency and longer lifetime than the pure Eu(TFNB)(3)bpy complex and other materials.