Synthesis, fluorescence properties of Eu(Ⅲ) complexes with novel carbazolefunctionalized β-diketone ligand

A novel carbazole functionalized β-diketone, methyl 6-(9-ethylcarbazole-3-yl)-oxoacetyl-2-pyridinecarboxylate (MEP), and its Corresponding Corresponding binary Eu(Ⅲ) complexes Eu(MEP)32H2O and ternary complex Eu(MEP)3Phen with 1,10-Phenanthroline (Phen) were pre-pared. The ligand was characterized based on elemental analysis, FT-IR, and 1H NMR, and the complexes were characterized with elemental analysis, FT-IR and thermogravimetric and differential thermal analysis (TG-DTA). The investigation of fluorescence properties of the com-plexes Eu(MEP)32H2O and Eu(MEP)3Phen showed that the Eu(Ⅲ) ion could be sensitized efficiently by the ligand to some extent, in par-titular, in the ternary system, the secondary ligand Phen acting as a light-harvesting center was involved in the highly efficient energy transfer process, and the emission was stronger than the binary complex. In addition, the introduction of the carbazole moiety enlarged the π-conjugated system of the ligand and enhanced the luminescent intensity of the complexes.