Study On The Properties Of Copper And Nickel Catalysts Protected By Bisphosphine Ligand

Nickel and copper are metal elements with abundant reserves on the earth.They are simple to exploit,low in price,and easy to form stable complexes with ligands.The spatial electronic structure can be adjusted by adjusting the ligands.They have similar and complementary catalytic properties with noble metals,so they have great potential to replace precious metal catalysts.Herein,we designed and developed a zero-valent nickel homogeneous catalytic system and a copper cluster which protected by bidentate phosphine,the specific work is as follows:Firstly,we have synthesized a zero-valent nickel complex Ni(dppp)₂ protected by a bisphosphine ligand,and it can also exist stably in the air.The study found that Ni(dppp)₂ can successfully catalyze the coupling of halogenated hydrocarbons and nitriles to synthesize ketones.The two-component catalytic system of nickel source and bisphosphine ligand is a catalytic system frequently used by researchers.We compared the catalytic system of Ni(dppp)₂with it.We also studied the reaction mechanism by means of mass spectrometry,nuclear magnetic resonance,electron paramagnetic resonance and some experimental methods,and found that the catalyst activity is due to the inhibition of the reaction by Ni(dppp)and free ligands.Then,we chose two coupling reactions to study the general applicability of the Ni(dppp)₂ catalytic system,and found that the Ni(bisphosphine)₂ catalytic system has great potential to replace the two-component catalytic system of nickel source and bisphosphine ligand.Secondly,we prepared the Cu₃I₂H(dppm)₃ cluster modified with bis(diphenylphosphine)methane ligand,and confirmed its precise structure using X-ray single crystal diffractometer and mass spectrometer.Meanwhile,we use the positively charged nature of Cu₃I₂H(dppm)₃ to interact with the SBA-15 carrier through electrostatic attraction,and anneal them to prepare a supported copper catalyst with precise atomic number.AHA coupling reaction and Click coupling reaction were used to evaluate the performance of the synthesized catalyst.Subsequently,we carried out various characterizations of the catalysts to initially explore the catalytic mechanism,such as TG,TEM,XRD,FT-IR,XPS and so on.