Synthesis And Catalytic Property Study Of Cu(?) And Ni(?) Complexes Based On Nitrogen–containing Ligands

Copper and nickel are a kind of biological elements with abundant reserves and low price,and the central metal atoms of copper and nickel catalysts have the advantages of low oxophilicity and excellent tolerance to various polar groups,and can achieve catalytic reduction,which were able to catalyze polymerization of norbornene and water decomposition reaction.The main contents are as follows:In the first section,the properties of the benzene ring-containing copper and nickel complexes for the polymerization of norbornene are investigated from the two aspects including electron effect and metal atom.On the basis of this,a series of nickel???complexes with the naphthalene ring-containing structure was synthesized.?Ar=H,L1;Ar=4-OMe,L2;Ar=4-CN,L3;Ar=4-CF₃,L4;Ar=2,6-iPr,L5?.The molecular structures of Ni?L2?₂,Ni?L4?₂,and Ni?L5?₂ were confirmed by single crystal X-ray diffraction analysis to exhibit a highly symmetric double ligand single active center.Under the action of MAO?methylaluminoxane?,such complexes showed good catalytic activity in the polymerization of norbornene?NB?.The optimal catalytic conditions were screened by conditional experiments,and the catalytic activities of complexes with different electronic effects under the experimental conditions were systematically investigated.The polymerization at 60°C with the molar ratio of Al/Ni is 2500/1 is the most effective condition.The activity of the catalyst is affected by the electron effect and the steric effect.The electron effect has a greater influence on the activity of the catalyst,and the nickel complex containing the electron withdrawing group has higher catalytic activity.Among them,the catalytic activity of Ni?L4?₂reached 3.06×10⁶ g PNB mol^-1Ni h^-1.In the second part,the catalytic application of[N,N]-coordinated tetradentate copper???complex in water decomposition reaction was studied.The complex was used as a homogeneous catalyst with bifunctional effect in cyclic voltammetry.The complex exhibited good catalytic activity and stability as a homogeneous catalyst.The initial voltage for water oxidation appeared at 1.10 V vs NHE.The overpotential of the analysis process was 230 mV,and the overpotential of the hydrogen separation process was 480 mV.