Novel flavonoid derivatives and their corresponding rare earth complexes: Synthesis and luminescent properties

A series of novel flavonoid derivatives and their corresponding Eu(III) and Tb(III) complexes were successfully prepared. The effect of different solvents, ligand concentrations and substituents on the luminescence intensity of ligands was studied. The results indicated that optimal luminescence concentration of the ligand was 500 mu M in ethanol. The luminescence intensity of the target complexes was studied by comparing different substituents on the ligands. Among these ligands, the ligand H4 containing -Cl possessed the strongest luminescence intensity. Besides, the luminescence quantum yield of the target complexes indicated that the luminescence performance of the Tb(III) complexes was better than that of the Eu(III) complexes.