Synthesis And Properties Of Cu(?) Complexes Based On Benzimidazophos Bidentate And Tetradentate Chelating Ligands

In this dissertation,two series of tetradentate and bidentate ligands?L1-L5?are synthesized,by the reaction of the ligands with different cuprous salts,a series of binuclear neutral copper complexes,ionic copper complexes and even thiophenol coordinating copper complexes were obtained.All the compounds are characterized by¹H NMR,³¹P NMR and elemental analysis.The crystal structures of these complexes were determined by X-ray single crystal diffraction.The photoluminescence properties of these complexes were systematically studied.These complexes were also deeply analyzed by time-dependent density functional theory?TD-DFT?.The luminescence of these complexes ranges from the blue to red light.Thirteen new Cu???complexes were synthesized using L1-L5 as the main ligands and[Cu?CH₃CN?₄]PF₆ or Cu X?X=I,Br,Cl,thiophenol?as copper sources.Single crystal structure analysis show that the central ions Cu in the complexes had deformed tetrahedral configuration.By increasing the conjugated system,regulating the substituents of the ligands,the emissions from blue light to red light are achieved.The binuclear neutral copper complexes containing iodide have excellent luminescent properties?with the quantum yield of about 50%?.When the ligands are the same,the maximum emission peaks of complexes Cu₂LI₂,Cu₂LBr₂,Cu₂LCl₂ increase in the order of I,Br and Cl.Among the five binuclear and mononuclear ionic copper complexes synthesized,the luminescence quantum efficiencies of the binuclear complexes are significantly higher than that of the mononuclear complexes?up to55.77%?.Moreover,complexes with center ion chelating with thiophenol also have better luminescence performance,and the quantum efficiency of complex Cu L4S was as high as 72.67%.The luminescence lifetime of these complexes at room temperature is between 0.92?s and 32.6?s.The DFT calculation results show that:the HOMO-LUMO orbital transitions of the iodine complexes are mainly contributed by the XLCT transition and the MLCT transition,mixed with the ILCT transition;and the HOMO-LUMO orbital transitions of the sulfur coordination complexes are mainly L'LCT with little MLCT contributes;and the ionic complexes HOMO-LUMO orbital transitions are mainly ILCT and MLCT transition,mixed with a small amount of L'LCT transition.