A thermodynamic study is reported for the coordination reaction of ZnT ( m-X)PP derivatives (X = NO2, Cl, OCH3, H or CH3) with various ligands L (L= imidazole (Im), 2-methylimidazole (Melm), clotrimidazole (CIM), imid...A thermodynamic study is reported for the coordination reaction of ZnT ( m-X)PP derivatives (X = NO2, Cl, OCH3, H or CH3) with various ligands L (L= imidazole (Im), 2-methylimidazole (Melm), clotrimidazole (CIM), imidazol-4-carboxaldehyde (4-CHOIm), unsymmetrical tetradentate copper Schiff base, Culm(p-C1), Ch(p-Br), and nickel Schiff base, Nilm(p-CI)), in dichloromethane solvent. Conversion of the four-coordinated ZnT( m-X)PP to the five-coordinated species is followed and isosbestic behavior is exhibited in the region among 450 and 700 nm. The reaction of a copper(II) or nickel(II) imidazolate Schiff base with ZnT( m-X)PP results in the formation of an imidazolate bridged heterobinuclear complex. The stochiometric number is unity for all axial ligands. The equilibrium constants were determined using the β band of ZnT( m-X)-PP in the 293–308 K range by the method of Rose and Drago. It increases with decrease in temperature, and ΔH0 0, Δ09 0. The stronger the nucleophilic ability of the axial ligand is, the larger the stability of the axial coordination product is. Hammet linear relationships and isoequilibrium relationships exist in the system studied.展开更多
The title compound Cd（Eim）3Cl2 （Eim = N-ethylimidazole） I has been synthesized and structurally characterized by single-crystal X-ray diffraction. The compound crystallizes in the monoclinic system, space group P2...The title compound Cd（Eim）3Cl2 （Eim = N-ethylimidazole） I has been synthesized and structurally characterized by single-crystal X-ray diffraction. The compound crystallizes in the monoclinic system, space group P2 1 with a = 8.0460（16）, b = 29.186（6）, c = 8.8960（18）A,β= 100.06（3）°, C15H24CdCl2N6, Mr = 471.71, V = 2056.9（7）A^3 Z = 4, Dc = 1.523 g/cm^3,/1 = 1.330 mm^-1, F（000） = 952, the final R = 0.0455 and wR = 0.0723. The title compound crystallizes with two molecules in the asymmetric unit. Each Cd^II ion is coordinated by three Eim ligands and two Cl anions in a trigonal bipyramidal geometry in two molecules. The weak intermolecular C-H……Cl hydrogen bonds link the molecules into two independent hydrogen-bonded chains running along the c axis. According to the cyclic voltammogram measurement in H2O, the electrode reaction should be a quasi-reversible process.展开更多
A new coordination polymer, namely [Zn（pdc）（bbi）]n {H2 pdc = 2,3-pyridine dicar- boxylic acid, bbi = 1,1-（1,4-butanediyl）bis（imidazole）}, has been prepared under hydrothermal conditions and characterized by el...A new coordination polymer, namely [Zn（pdc）（bbi）]n {H2 pdc = 2,3-pyridine dicar- boxylic acid, bbi = 1,1-（1,4-butanediyl）bis（imidazole）}, has been prepared under hydrothermal conditions and characterized by elemental analysis, IR, and single-crystal X-ray diffraction. It crystallizes in monoclinic, space group P21 /n with a = 8.436（3）, b = 16.988（5）, c = 12.106（4）, β = 92.204（5）°, V = 1733.6（9）3, Z = 4, C17 H17 N5 O4 Zn, Mr = 420.73, Dc = 1.612 g/cm3, F（000） = 864, μ（MoKa） = 0.452 mm-1, the R = 0.0672 and wR = 0.1645. In the mononuclear complex, each Zn（II） is five-coordinated by one carboxylate O and one pyridyl N atoms from one pdc anion, one carboxylate O atom from another pdc anion, and two N atoms from two bib ligands. The Zn（II） ions are connected by pdc ligands to form skeleton chains, and bbi ligands further link them to construct a 2D framework. The thermal and luminescence properties of the complex were also investigated.展开更多
Two new Cu（Ⅰ） complexes [CuCl（3-PyOH）（PPh_3）_2]（1） and [Cu_2（μ-Cl）_2（4-Stpy）（Ph_3P）_3]（2）（PyOH = hydroxypyridine; stpy = styrylpyridine） with triphenylphosphine and pyridine derivatives have been s...Two new Cu（Ⅰ） complexes [CuCl（3-PyOH）（PPh_3）_2]（1） and [Cu_2（μ-Cl）_2（4-Stpy）（Ph_3P）_3]（2）（PyOH = hydroxypyridine; stpy = styrylpyridine） with triphenylphosphine and pyridine derivatives have been synthesized and characterized by elemental analysis and X-ray single-crystal diffraction. Compound 1 crystallizes in monoclinic, space group P2_1/c with a = 9.8945（7）, b = 37.266（2）, c = 10.9461（7） A, β = 116.0750（10）°, V = 3625.3（4） A^3, Z = 4, D_c = 1.350 Mg/cm^（-3）, μ = 0.801 mm^（-1）, F（000） = 1528, the final R = 0.0320 and w R = 0.0729 for 18568 observed reflections（I 〉 2σ（I））, R（all data） = 0.0413, wR（all data） = 0.0769, completeness to theta of 25.01 is 99.9% and GOF = 1.037. Compound 2 crystallizes in monoclinic, space group P2_1/c with a = 11.290（3）, b = 20.388（5）, c = 24.092（6） A, β = 102.028（4）°, V = 5424（2） A^3, Z = 4, D_c = 1.428 Mg/cm^（-3）, μ = 1.016 mm^（-1）, F（000） = 2408, the final R = 0.0568 and w R = 0.1486 for 27644 observed reflections（I 〉 2σ（I））, R（all data） = 0.0716, wR（all data） = 0.1592, completeness to theta of 25.01 is 99.9% and GOF = 1.056. Two new Cu（I） complexes have been utilized as catalysts for N-arylation of imidazole and both showed good catalytic activity.展开更多
Three hexakis（imidazole）metallo complexes of Co, Cd and Ni were synthesized and spectroscopically characterized. The crystal and molecular structures have been determined by X-ray crystallography analysis. The metal...Three hexakis（imidazole）metallo complexes of Co, Cd and Ni were synthesized and spectroscopically characterized. The crystal and molecular structures have been determined by X-ray crystallography analysis. The metal ions have an octahedral geometry with the MN6 chromophore. The electrochemical experimental results indicate that both [Co（Im）6]C12·2HCl·2H2O （1） and [Ni（Im）6]C12·4H2O （3） [Im=imidazole] could interact with DNA mainly by intercalation.展开更多
The X-ray crystal structure of [(dtma)ZnImZn(dtma)]ClO_4·2.5H_2O (Hdtma=4-Diethyl- enetriamineacetic acid) was determined.The crystal is of orthorhombic,space group Pbcn with a- 14.104(5),b=14.897(5),c=25.384(9),...The X-ray crystal structure of [(dtma)ZnImZn(dtma)]ClO_4·2.5H_2O (Hdtma=4-Diethyl- enetriamineacetic acid) was determined.The crystal is of orthorhombic,space group Pbcn with a- 14.104(5),b=14.897(5),c=25.384(9),and Z=8.The least-square refinement of the structure leads to conventional R factor of 0.066.The magnetic properties of [(dtma)CulmZn(dtma)]CIO_4·2.5H_2O were investigated.From the single crystal ESR spectra of Zn—Im—Zn dimer doped with Cu—Im—Zn complex,the anisotropic g and A tensors and electronic spin-density of the Cu—Zn complex are obtained and the bonding nature of Cu is discussed.展开更多
A new imidazolate bridged Cu^(2+),Zn^(2+)binuclear complex[(dtma) CulmZn (dtma)]ClO_4· 2.5H_2O taken as active site model for Cu,Zn-SOD has been synthesized and its crystal structure determined.All the bond lengt...A new imidazolate bridged Cu^(2+),Zn^(2+)binuclear complex[(dtma) CulmZn (dtma)]ClO_4· 2.5H_2O taken as active site model for Cu,Zn-SOD has been synthesized and its crystal structure determined.All the bond lengths, bond angles and the distance between Cu and Zn atoms in Cu-Im- Zn core of the model complex are close to those in Cu,Zn-SOD.ESR parameters of the model complex as a function of pH show that the imidazolate bridge is stable in pH range 10—12,and is broken on Zn side at pH～9.With decreasing pH,the imidazole is released at pH～4 and the dtma ligand dissociates from the Cu containing fragment at pH～2.4.展开更多
基金National Natural Science Foundation of China (No.29871018Tianjin Natural Science Foundation
文摘A thermodynamic study is reported for the coordination reaction of ZnT ( m-X)PP derivatives (X = NO2, Cl, OCH3, H or CH3) with various ligands L (L= imidazole (Im), 2-methylimidazole (Melm), clotrimidazole (CIM), imidazol-4-carboxaldehyde (4-CHOIm), unsymmetrical tetradentate copper Schiff base, Culm(p-C1), Ch(p-Br), and nickel Schiff base, Nilm(p-CI)), in dichloromethane solvent. Conversion of the four-coordinated ZnT( m-X)PP to the five-coordinated species is followed and isosbestic behavior is exhibited in the region among 450 and 700 nm. The reaction of a copper(II) or nickel(II) imidazolate Schiff base with ZnT( m-X)PP results in the formation of an imidazolate bridged heterobinuclear complex. The stochiometric number is unity for all axial ligands. The equilibrium constants were determined using the β band of ZnT( m-X)-PP in the 293–308 K range by the method of Rose and Drago. It increases with decrease in temperature, and ΔH0 0, Δ09 0. The stronger the nucleophilic ability of the axial ligand is, the larger the stability of the axial coordination product is. Hammet linear relationships and isoequilibrium relationships exist in the system studied.
基金the National Natural Science Foundation of China (20601015)
文摘The title compound Cd（Eim）3Cl2 （Eim = N-ethylimidazole） I has been synthesized and structurally characterized by single-crystal X-ray diffraction. The compound crystallizes in the monoclinic system, space group P2 1 with a = 8.0460（16）, b = 29.186（6）, c = 8.8960（18）A,β= 100.06（3）°, C15H24CdCl2N6, Mr = 471.71, V = 2056.9（7）A^3 Z = 4, Dc = 1.523 g/cm^3,/1 = 1.330 mm^-1, F（000） = 952, the final R = 0.0455 and wR = 0.0723. The title compound crystallizes with two molecules in the asymmetric unit. Each Cd^II ion is coordinated by three Eim ligands and two Cl anions in a trigonal bipyramidal geometry in two molecules. The weak intermolecular C-H……Cl hydrogen bonds link the molecules into two independent hydrogen-bonded chains running along the c axis. According to the cyclic voltammogram measurement in H2O, the electrode reaction should be a quasi-reversible process.
基金Supported by the Key Scientific and Technological Project of Henan(122102210250)the Foundation of Henan Educational Committee(13A150102)the key disciplines of analytical chemistry of Henan province
文摘A new coordination polymer, namely [Zn（pdc）（bbi）]n {H2 pdc = 2,3-pyridine dicar- boxylic acid, bbi = 1,1-（1,4-butanediyl）bis（imidazole）}, has been prepared under hydrothermal conditions and characterized by elemental analysis, IR, and single-crystal X-ray diffraction. It crystallizes in monoclinic, space group P21 /n with a = 8.436（3）, b = 16.988（5）, c = 12.106（4）, β = 92.204（5）°, V = 1733.6（9）3, Z = 4, C17 H17 N5 O4 Zn, Mr = 420.73, Dc = 1.612 g/cm3, F（000） = 864, μ（MoKa） = 0.452 mm-1, the R = 0.0672 and wR = 0.1645. In the mononuclear complex, each Zn（II） is five-coordinated by one carboxylate O and one pyridyl N atoms from one pdc anion, one carboxylate O atom from another pdc anion, and two N atoms from two bib ligands. The Zn（II） ions are connected by pdc ligands to form skeleton chains, and bbi ligands further link them to construct a 2D framework. The thermal and luminescence properties of the complex were also investigated.
基金Supported by the National Natural Science Foundation of China(NSFC 21102102)
文摘Two new Cu（Ⅰ） complexes [CuCl（3-PyOH）（PPh_3）_2]（1） and [Cu_2（μ-Cl）_2（4-Stpy）（Ph_3P）_3]（2）（PyOH = hydroxypyridine; stpy = styrylpyridine） with triphenylphosphine and pyridine derivatives have been synthesized and characterized by elemental analysis and X-ray single-crystal diffraction. Compound 1 crystallizes in monoclinic, space group P2_1/c with a = 9.8945（7）, b = 37.266（2）, c = 10.9461（7） A, β = 116.0750（10）°, V = 3625.3（4） A^3, Z = 4, D_c = 1.350 Mg/cm^（-3）, μ = 0.801 mm^（-1）, F（000） = 1528, the final R = 0.0320 and w R = 0.0729 for 18568 observed reflections（I 〉 2σ（I））, R（all data） = 0.0413, wR（all data） = 0.0769, completeness to theta of 25.01 is 99.9% and GOF = 1.037. Compound 2 crystallizes in monoclinic, space group P2_1/c with a = 11.290（3）, b = 20.388（5）, c = 24.092（6） A, β = 102.028（4）°, V = 5424（2） A^3, Z = 4, D_c = 1.428 Mg/cm^（-3）, μ = 1.016 mm^（-1）, F（000） = 2408, the final R = 0.0568 and w R = 0.1486 for 27644 observed reflections（I 〉 2σ（I））, R（all data） = 0.0716, wR（all data） = 0.1592, completeness to theta of 25.01 is 99.9% and GOF = 1.056. Two new Cu（I） complexes have been utilized as catalysts for N-arylation of imidazole and both showed good catalytic activity.
基金Project supported by the Program for New Century Excellent Talents in University （No. NCET-04-0649） and the National Natural Science Foundation of China （Nos. 20275020, 20475030）.
文摘Three hexakis（imidazole）metallo complexes of Co, Cd and Ni were synthesized and spectroscopically characterized. The crystal and molecular structures have been determined by X-ray crystallography analysis. The metal ions have an octahedral geometry with the MN6 chromophore. The electrochemical experimental results indicate that both [Co（Im）6]C12·2HCl·2H2O （1） and [Ni（Im）6]C12·4H2O （3） [Im=imidazole] could interact with DNA mainly by intercalation.
文摘The X-ray crystal structure of [(dtma)ZnImZn(dtma)]ClO_4·2.5H_2O (Hdtma=4-Diethyl- enetriamineacetic acid) was determined.The crystal is of orthorhombic,space group Pbcn with a- 14.104(5),b=14.897(5),c=25.384(9),and Z=8.The least-square refinement of the structure leads to conventional R factor of 0.066.The magnetic properties of [(dtma)CulmZn(dtma)]CIO_4·2.5H_2O were investigated.From the single crystal ESR spectra of Zn—Im—Zn dimer doped with Cu—Im—Zn complex,the anisotropic g and A tensors and electronic spin-density of the Cu—Zn complex are obtained and the bonding nature of Cu is discussed.
文摘A new imidazolate bridged Cu^(2+),Zn^(2+)binuclear complex[(dtma) CulmZn (dtma)]ClO_4· 2.5H_2O taken as active site model for Cu,Zn-SOD has been synthesized and its crystal structure determined.All the bond lengths, bond angles and the distance between Cu and Zn atoms in Cu-Im- Zn core of the model complex are close to those in Cu,Zn-SOD.ESR parameters of the model complex as a function of pH show that the imidazolate bridge is stable in pH range 10—12,and is broken on Zn side at pH～9.With decreasing pH,the imidazole is released at pH～4 and the dtma ligand dissociates from the Cu containing fragment at pH～2.4.
