Synthesis, photophysical characteristics and geometry optimization of Tris (2-benzoylacetophenonate)europium complexes with 2, 2′-Bipyridine derivatives

A series based on octa coordinated tris(2-benzoylacetophenonate)europium complexes were synthesized with bidentate heteroaromatic auxiliary ligands. 2,2 '-Bipyridine (Bpy) and its derivatives synthesized in the laboratory were used as auxiliary ligands. The structural analysis of synthesized materials was done by various spectroscopic techniques. Their photoluminescent characteristics specified the effective sensitization of trivalent europium ion via antenna effect. As an outcome of this sensitization, these complexes demonstrate good luminescence intensity, high quantum efficiency and long luminescence lifetime. The CIE chromaticity coordinates (x, y and u', v') were designed to indicate bright red emission. Luminescence decay time data were calculated by investigating the lambda em well-suited with the transition of the type (5)D0 -> F-7(2). The molecular parameters of the geometrically optimized complexes were derived from the semi-empirical Sparkle/RM1 method. Theoretical Judd-Ofelt and photophysical parameters were estimated by LUMPAC software ascribed with experimental data, indicating the efficacy of this method. Furthermore, these luminous ternary europium complexes can be utilized as red light emitting material in designing flat panel displays and various optoelectronic devices.