Synthesis and Luminescence Properties of Europium(III) Complexes Based on Bipyridine Derivatives with Carbazole Moieties

Three N,N-bidentate ligands,5,5′-dibromo-2,2′-bipyridine(L2) and two carbazole containing ligands of 5-bromo-5′-carbazolyl-2,2′-bipyridine(L3),5,5′-dicarbazolyl-2,2′-bipyridine(L4) have been successfully synthesized based on 2,2′-bipyridine(L1).Employing dibenzoylmethane(DBM) and L1-L4 as the sensitizing ligands,a series of europium(Ⅲ) complexes(Eu(DBM) 3 L1-Eu(DBM) 3 L4) have been obtained.All the europium(Ⅲ) complexes show bright red characteristic emission of Eu(Ⅲ) 5 D 0-7 F J(J=0,1,2,3,4) under the excitation wavelength at 387 nm.The introduction of carbazole moieties improves the UV-Vis absorption and luminescence intensities of the europium(Ⅲ) complexes.