Study On Preparation, Structure And Reactivity Of Iridium And Nickel Complexes With Schiff Base Ligands

Metal complexes are a kind of coordination compounds formed by coordination bonds between ligands and metal atoms or ions.Among them,most of the ions or atoms coordinated with transition metals have broad application prospects in optics,biology,magnetism,etc.Based on Schiff base ligands,a series of complexes containing iridium and nickel were synthesized,and their structures and catalytic properties were investigated.The main contents of the thesis are shown as follows:（1）β-Ketoamine ligands containing different substituents were obtained by the reactions of acetyl acetones and aniline derivatives.A series of iridium complexes with excellent catalytic activity were successfully prepared by ligand coordination of the ligands with[Cp*Ir Cl₂]₂.The structure of the complex was analyzed by nuclear magnetic resonance,elemental analysis,infrared and ultraviolet.Finally,the molecular structure of the complex was determined by X-ray single crystal diffraction.Using the synthesized iridium complex as the catalyst,the amidation of benzaldehyde and hydroxylamine was used as the template to optimize the reaction conditions.The effects of catalyst loading,solvent,base and temperature on the reaction were studied.The substrate scope of aldehydes was investigated under the optimal conditions.The experimental results show that these air-insensitive iridium complexes exhibit ideal catalytic activity in the preparation of amides under mild conditions.（2）Using 2-quinoline formaldehyde and aniline derivatives as starting materials,four kinds of Schiff base ligands with different substituents were synthesized.A series of N,N-coordinated nickel（II）complexes were prepared by the reaction of ligands with Ni Cl₂·6H₂O.The nickel（II）complexes were characterized by infrared spectroscopy,elemental analysis and X-ray single crystal diffraction.In order to explore the catalytic activity of nickel complex,the primary amide and alcohol were used as template substrates,and the catalyst,solvent,base and temperature of the reaction were optimized.The substrates scope of primary amides and alcohols was investigated under the optimal conditions.It was observed that the nickel complex stable in air and water showed effective catalytic activity and functional group tolerance to the amidation of primary amides and alcohols with a wide range of substrates,and only water was the byproduct of the amidation reaction catalyzed by the complex.