几种铼配合物的合成和发光性能研究

hree N, N-bidentate ligands, 5,5'-dibromo-2,2'-bipyridine (L1) and two carbazole containing ligands of 5-bromo-5'-carbazolyl-2,2'-bipyridine (L2), 5,5'-dicarbazolyl-2,2'-bipyridine (L3), and their corresponding rhenium Re(CO)3LCl complexes (ReL1-ReL3) have been successfully synthesized and characterized by elemental analysis, 1H NMR and IR spectra. Their photophysical properties and thermal analysiswere also described. In CH2Cl2 solution at room temperature, all complexes display intense absorption bands at ca. 220-350 nm, which can be assigned to spin-allowed intraligand transitions, and the low energy broad bands in the 360-480 nm region are attributed to the metal to ligand charge-transfer (MLCT). The introduction of carbazole moieties improves the MLCT absorption and molar extinction coefficient of these complexes. Upon the excitation on the peak maxima, all complexes show strong emissions around 620 nm, which are assigned to MLCT phosphorescence. The photoluminescence lifetime decay of Re(I) complexes were measured and the quantum efficiencies of the rhenium(I) complexes were calculated by using air-equilibrated [Ru(bpy)3]2+.2Cl- aqueous solution as standard (Φstd =0.028). The complexes with appended carbazole moieties exhibit enhanced luminescence performances relative to ReL1.