Two new coordination polymers,[Ni(Hpdc)(bib)(H_(2)O)]_(n)(1)and{[Ni(bib)_(3)](ClO_(4))_(2)}_(n)(2),were prepared by mixing Ni^(2+),3,5⁃pyrazoledicarboxylic acid(H3pdc)/p⁃nitrobenzoic acid and 1,4⁃bis(imidazol⁃1⁃ylmeth...Two new coordination polymers,[Ni(Hpdc)(bib)(H_(2)O)]_(n)(1)and{[Ni(bib)_(3)](ClO_(4))_(2)}_(n)(2),were prepared by mixing Ni^(2+),3,5⁃pyrazoledicarboxylic acid(H3pdc)/p⁃nitrobenzoic acid and 1,4⁃bis(imidazol⁃1⁃ylmethyl)butane(bib)by a hydrothermal method,respectively.X⁃ray crystallography reveals a 2D network constructed by six⁃coordinated Ni(Ⅱ)centers,bib,and Hpdc2-ligands in complex 1,while a 2D network is built by Ni(Ⅱ)and bib ligands in 2.Furthermore,the quantum⁃chemical calculations have been performed on‘molecular fragments’extracted from the crystal structure of 1 using the PBE0/LANL2DZ method in Gaussian 16 and the VASP program.CCDC:2343794,1;2343798,2.展开更多
α-Diimide catalysts have attracted widespread attention due to their unique chain walking characteristics.A series ofα-diimide nickel/palladium catalysts with different electronic effects and steric hindrances were ...α-Diimide catalysts have attracted widespread attention due to their unique chain walking characteristics.A series ofα-diimide nickel/palladium catalysts with different electronic effects and steric hindrances were designed and synthesized for olefin polymerization.In this work,we synthesized a series of asymmetricα-diimide nickel complexes with different steric hindrances and used them for ethylene polymerization.These nickel catalysts have high ethylene polymerization activity,up to 6.51×10^(6)g·mol^(−1)·h^(−1),and the prepared polyethylene has a moderate melting point and high molecular weight(up to 38.2×10^(4)g·mol^(−1)),with a branching density distribution between 7 and 94 branches per 1000 carbons.More importantly,the polyethylene prepared by these catalysts exhibits excellent tensile properties,with strain and stress reaching 800%and 30 MPa,respectively.展开更多
A new complex with binuclear nickel(Ⅱ) complex [Ni2(bbimp)(CH3CH2OH)2Cl2]Cl· 4H2O (bbimp=2,6 bis[bis(2 benzimidazolylmethyl)]aminomethyl 4 methylpheno)(o)had been synthesized and characterized by elementary anal...A new complex with binuclear nickel(Ⅱ) complex [Ni2(bbimp)(CH3CH2OH)2Cl2]Cl· 4H2O (bbimp=2,6 bis[bis(2 benzimidazolylmethyl)]aminomethyl 4 methylpheno)(o)had been synthesized and characterized by elementary analysis, IR and UV. The molecular structure of the title complex was determined by X ray single crystal diffraction method. The crystal is monoclinic, space group P21/n with a=20.803(2)? , b=30.708(3)? , c=20.959(2)? , β =105.776(2)° , Z=8, V=12885(2)? 3, Dx=1.132Mg· m- 3, μ =0.755mm- 1, F(000)=4592, R1=0.1267, S=1.376. It was showed that the nickel? cation is the central ion of a distorted octahedral coordination with two N belonging to benzimidazole, a bridging phenolate O, a N of tertiary amine, a Cl anion, and an O of an ethanol molecule. Two nickel? cations in a molecular structure had the same coordinated environment. CCDC: 197601.展开更多
Three binuclear Nickel(Ⅱ) complexes were synthesized, bridged with dithiooxalate, Ni2(Bpy)3(Dto)2(H2O)3 (1), Ni2(Phen)3(Dto)2(H2O)3 (2) and Ni2(Me2Bpy)3(Dto)2(H2O)2 (3) (Bpy=2,2′-Bipyridine, Phen=1,10-phenanthroline...Three binuclear Nickel(Ⅱ) complexes were synthesized, bridged with dithiooxalate, Ni2(Bpy)3(Dto)2(H2O)3 (1), Ni2(Phen)3(Dto)2(H2O)3 (2) and Ni2(Me2Bpy)3(Dto)2(H2O)2 (3) (Bpy=2,2′-Bipyridine, Phen=1,10-phenanthroline, Me2Bpy=4,4′-dimethyl-2,2′-bipyridine, Dto2-=Dithiooxalate), and characterized by elemental analyses, IR, UV-Visible spectra, conductance. The variable temperature magnetic susceptibilities for the complexes were measured in the range of temperature between 1.5 K and 298 K. Experimental data of magnetic susceptibility were successfully fit to theoretical value based on the spin Hamiltonian operator: H=-2JS1S2, S1=S2=1, giving the magnetic exchange parameters of 2J=-52.8 cm-1. This result indicates the presence of a strong antiferromagnetic spin exchange interaction between the Ni(Ⅱ) ions. The magnetic exchange parameters of the binuclear Nickel(Ⅱ) complexes bridged with dithiooxalate is larger than that of the binuclear Nickel(Ⅱ) complexes bridged with oxalate. Dithiooxalate is more effective to transfer antiferromagnetic spin exchange interaction between the Ni(Ⅱ) ions than oxalate.展开更多
文摘Two new coordination polymers,[Ni(Hpdc)(bib)(H_(2)O)]_(n)(1)and{[Ni(bib)_(3)](ClO_(4))_(2)}_(n)(2),were prepared by mixing Ni^(2+),3,5⁃pyrazoledicarboxylic acid(H3pdc)/p⁃nitrobenzoic acid and 1,4⁃bis(imidazol⁃1⁃ylmethyl)butane(bib)by a hydrothermal method,respectively.X⁃ray crystallography reveals a 2D network constructed by six⁃coordinated Ni(Ⅱ)centers,bib,and Hpdc2-ligands in complex 1,while a 2D network is built by Ni(Ⅱ)and bib ligands in 2.Furthermore,the quantum⁃chemical calculations have been performed on‘molecular fragments’extracted from the crystal structure of 1 using the PBE0/LANL2DZ method in Gaussian 16 and the VASP program.CCDC:2343794,1;2343798,2.
基金supported by the National Natural Science Foundation of China(52203016)the USTC Research Funds of the Double First-Class Initiative(YD9990002018)+3 种基金the Overseas Students Innovation and Entrepreneurship Support Program Project of Anhui Province(2021LCX022)the Key R&D Projects in Anhui Province(2022i01020012)the Natural Science Foundation of Hefei(2022039)the Excellent Research and Innovation Team Project of Anhui Province(2022AH010001).
文摘α-Diimide catalysts have attracted widespread attention due to their unique chain walking characteristics.A series ofα-diimide nickel/palladium catalysts with different electronic effects and steric hindrances were designed and synthesized for olefin polymerization.In this work,we synthesized a series of asymmetricα-diimide nickel complexes with different steric hindrances and used them for ethylene polymerization.These nickel catalysts have high ethylene polymerization activity,up to 6.51×10^(6)g·mol^(−1)·h^(−1),and the prepared polyethylene has a moderate melting point and high molecular weight(up to 38.2×10^(4)g·mol^(−1)),with a branching density distribution between 7 and 94 branches per 1000 carbons.More importantly,the polyethylene prepared by these catalysts exhibits excellent tensile properties,with strain and stress reaching 800%and 30 MPa,respectively.
文摘A new complex with binuclear nickel(Ⅱ) complex [Ni2(bbimp)(CH3CH2OH)2Cl2]Cl· 4H2O (bbimp=2,6 bis[bis(2 benzimidazolylmethyl)]aminomethyl 4 methylpheno)(o)had been synthesized and characterized by elementary analysis, IR and UV. The molecular structure of the title complex was determined by X ray single crystal diffraction method. The crystal is monoclinic, space group P21/n with a=20.803(2)? , b=30.708(3)? , c=20.959(2)? , β =105.776(2)° , Z=8, V=12885(2)? 3, Dx=1.132Mg· m- 3, μ =0.755mm- 1, F(000)=4592, R1=0.1267, S=1.376. It was showed that the nickel? cation is the central ion of a distorted octahedral coordination with two N belonging to benzimidazole, a bridging phenolate O, a N of tertiary amine, a Cl anion, and an O of an ethanol molecule. Two nickel? cations in a molecular structure had the same coordinated environment. CCDC: 197601.
文摘Three binuclear Nickel(Ⅱ) complexes were synthesized, bridged with dithiooxalate, Ni2(Bpy)3(Dto)2(H2O)3 (1), Ni2(Phen)3(Dto)2(H2O)3 (2) and Ni2(Me2Bpy)3(Dto)2(H2O)2 (3) (Bpy=2,2′-Bipyridine, Phen=1,10-phenanthroline, Me2Bpy=4,4′-dimethyl-2,2′-bipyridine, Dto2-=Dithiooxalate), and characterized by elemental analyses, IR, UV-Visible spectra, conductance. The variable temperature magnetic susceptibilities for the complexes were measured in the range of temperature between 1.5 K and 298 K. Experimental data of magnetic susceptibility were successfully fit to theoretical value based on the spin Hamiltonian operator: H=-2JS1S2, S1=S2=1, giving the magnetic exchange parameters of 2J=-52.8 cm-1. This result indicates the presence of a strong antiferromagnetic spin exchange interaction between the Ni(Ⅱ) ions. The magnetic exchange parameters of the binuclear Nickel(Ⅱ) complexes bridged with dithiooxalate is larger than that of the binuclear Nickel(Ⅱ) complexes bridged with oxalate. Dithiooxalate is more effective to transfer antiferromagnetic spin exchange interaction between the Ni(Ⅱ) ions than oxalate.
