Design,preparation And Application Of α-diimide Nickel(Ⅱ)Complex

Purpose:Design ofα-diimide nickel complexes with higher catalytic activity for ethylene polymerization[（Ar N=C（Me）C（Me）=NAr）]Ni Br₂（Ar=2,6-Me₂-4-{CH（4-FC₆H₄）₂}C₆H₂Ni1,2-Me-6-Et-4-{CH（4-FC₆H₄）₂}C₆H₂Ni2,2,4-{CH（4-FC₆H₄）₂}₂-6-Me C₆H₂Ni3,2,4-{CH（4-FC₆H₄）₂}₂-6-Et C₆H₂Ni4,2,4-{CH（4-FC₆H₄）₂}₂-6-i Pr C₆H₂Ni5）for the preparation of bio-polyethylene materials with controllable macrostructure,filling the gap of bio-polyethylene materials catalyst family;The potential ofα-diimide nickel complex catalysts Ni1-Ni5 for external pharmacological activity in addition to catalytic activity was explored by computer aided technology;The traditional synthesis route ofα-diimide nickel complex was optimized and a new reaction route was obtained;Characterization and analysis of synthetic products to provide new spectral data;The application research of ethylene polymerization catalyzed byα-diimide nickel complexes and the characterization of polyethylene materials were carried out,the diversity of biological polyethylene materials was expanded,mainly polyethylene materials with drug carrier and bio-implantation potentialMethods:The Brookhart-type catalyst was used as a template for the structural design ofα-diimino nickel complexes by fine-tuning the N-aryl substituent.The targets ofα-diimide nickel complexes Ni1-Ni5 were determined by pharmmapper database,and the Ni1-Ni5 targets were correlated with diseases using the Dis Ge NET database.Autodock vina molecular docking was used to investigate the binding energy,binding location and binding way between catalyst and disease-associated targets.Finally,DAVID database searched for disease pathways and analyzed the mechanism of catalyst treatment of disease.The reaction conditions ofα-diimide nickel complex synthesis were screened and optimized using a controlled variable approach based on literature reports,and the reaction process was monitored by thin layer chromatography.The synthetic compounds were characterized by FT-IR,NMR(¹H,¹³C,¹⁹F)and X-ray spectra.By changing the polymerization conditions and using fiveα-diimide nickel complexes for ethylene polymerization to obtain the target bio-polyethylene material.The polymers were characterized by gel chromatography,differential thermogravimetric analyzer and dynamic mechanics analyzer.Results:Theα-diimide nickel complexes Ni2 and Ni4 have potential pharmacological activities,mainly anti-depression,anti-schizophrenia,anti-tumor and anti-inflammatory.Molecular docking results showed that Ni2 and Ni4 bind most stably to targets related to mental disorders such as depression and schizophrenia.DAVID analysis showed that one of the possible mechanisms of Ni2 and Ni4against psychiatric disorders is to improve mitochondrial dysfunction by regulating mitochondrial membrane permeability for the ultimate therapeutic purposes.The total yield ofα-diimide nickel complexes Ni1-Ni5 was increased by more than20%compared to the structurally similar complexes after the optimization of the preparation process,ranging from,ranging from 67.6%to 79.1%.X-ray diffraction analysis of the crystal structures of L3,Ni1 and Ni5 showed the distorted tetrahedral geometry of the nickel analogues and the differences in spatial protection provided by the ortho-substituents.All nickel complexes,under suitable activation,showed high activity for ethylene polymerization with a predilection towards forming branched high molecular weight polyethylene with narrow dispersity.The fine-tuning of N-aryl ortho-position ofα-diimide nickel complexes and the modification of polymerization conditions can realize the macro-control of polyethylene structure.Notably the most sterically bulky Ni5,can generate polyethylene with a molecular weight of more than 1.5 million at 30℃using Et Al Cl₂as a cocatalyst.In addition,stress–strain recovery tests reveal this high molecular weight polymers to exhibit characteristics of thermoplastic elastomers（TPEs）,which has a huge application prospect in the field of biological implant materials.By activating with either Et Al Cl₂,Et₂Al Cl or EASC,Ni5 was exceptionally active（0.9–1.0 10⁷g of PE per（mol of Ni）per h）at an operating temperature of 40℃.Furthermore,the polyethylene generated displayed molecular weights close to one million g mol 1(Mw range:829–922 kg mol^-1)with high branching densities（86–102/1000 carbons）and a selectivity for short chain branches（%Me?94.3%（Et Al Cl2）,87.2%（Et2Al Cl）,87.7%（EASC））,which is is expected to be an excellent drug carrier material.Further analysis of the mechanical properties of the polymers produced at 30℃,40℃and 50℃using Ni5 highlighted the key role played by crystallinity（X_c）and molecular weight（Mw）on tensile strength and elongation at break.Conclusion:1)It provides a new synthesis route ofα-diimide metal complexes with catalytic activity of ethylene polymerization and pharmacological activity potentialwithout complicated reaction and purification,resulting in high yield and high purity products,meanwhile reducing cost waste and production time in the synthesis ofα-diimino metal complexes.2)It explore the application of these newα-diimide catalysts in the field of olefin polymerization,and provide new bio-polyethylene materials with the potential of biotherapeutic engineering,and promote the development of pharmaceutical and other biological disciplines.