Synthesis, Characterization and Emission Properties of a Mixed Metal Complex of Europium (III) and Terbium (III) with a Tripodal Heptadentate Schiff Base Ligand

The preparation and characterization of a novel mixed metal complex of europium (III) and terbium (III) of a tripodal heptadentate Schiff-base ligand N [CH2CH2N=CH (2-OH-3-MeC6H3)](3) (H3L1) have been studied. The complex was prepared by the reaction of [EuL1] and [TbL1] in N, N-dimethylformamide. The ratio of europium (III) to terbium (III) in the mixed metal complex was found to be 3 to 7. The molecular structure of [Eu0.3Tb0.7L1] was determined by X-ray crystallography. The crystal structure analysis revealed that the Schiff-base behaves as a tri-deprotonated heptadentate ligand encapsulating the each metal ion within the N4O3 cavity. Under the excitation of UV light, the solid state of the complex exhibited red emission corresponding to europium (Ill) ion. The emission bands of D-5(0) -> F-7(j) (j = 2, 3, 4) were observed at 609, 652, and 706 nm, respectively. On the other hand, the green emission corresponding to terbium (III) ion was not observed.