The novel complex [Zn2（Mba）3（Phen）2EtOH）]·ClO4 （Hrnba = methoxybenzoic acid, Phen = 1,10-phenanthroline, EtOH = ethanol） was synthesized by hydrothermal reactions, and its structure was determined by X-ray...The novel complex [Zn2（Mba）3（Phen）2EtOH）]·ClO4 （Hrnba = methoxybenzoic acid, Phen = 1,10-phenanthroline, EtOH = ethanol） was synthesized by hydrothermal reactions, and its structure was determined by X-ray diffraction. The crystal belongs to the triclinic system, space group Pi with a = 1.15362（1）, b = 1.3655（3）, c = 1.61451（1） nm, α= 72.842（2）, β = 83.259（3）, y = 72.083（2）°, V = 2.3112（6） nm3, Z = 2,μ（MoKa） = 11.71 cm-1, F（000） = 1120, R = 0.0552 and wR = 0.1157 （I 〉 2σ（I））. The two centric zinc（H） ions in the complex locate in a distorted octahedral coordination geometry and a distorted trigonal bipyramid coordination geometry, respectively. Two bridging bidentate carboxyl groups and a μ2-O carboxyl group from three methoxybenzoic acids act as the bridge to link two Zn（Ⅱ） ions. The asymmetric units are connected by π-π packing interactions between aromatic rings to form a three-dimensional supramolecular network. The experimental results show a good fluorescence property for the complex.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 series of imidazolate-bridged heteropolynuclear complexes containing Cu2+ or Zn2+ were synthesized and characterized by reflectance spectroscopy, NMR and X-ray diffraction analysis. The bonding nature and the stabil...A series of imidazolate-bridged heteropolynuclear complexes containing Cu2+ or Zn2+ were synthesized and characterized by reflectance spectroscopy, NMR and X-ray diffraction analysis. The bonding nature and the stability of imidazolate bridges in the complexes were studied by ESR spectroscopy, and the catalytic activity of the complexes in dismutation of O-2 was determined by NBT method. Results obtained indicate that the central Cu with N4 and N2O2 square planar or N4O square pyramidal coordination in which there is a weak bond H2O or ClO-4 on axial position, has a comparatively higher activity, but that with N5 square pyramidal having a strong bond axial ligand has almost no activity. Thus the results imply a possible formation of Cu-O-2 intermediate adduct in the catalytic process by Cu, Zn-SOD.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Supported by the Scientific and Technological Program of Hunan Provincial Department of Science and Technology (No. 2010JT4041)Hunan Provincial Department of Education (No. 11C0186)Hunan Provincial Key Discipline Construction and Hunan College Key Laboratory of Functional Organometallic Materials
文摘The novel complex [Zn2（Mba）3（Phen）2EtOH）]·ClO4 （Hrnba = methoxybenzoic acid, Phen = 1,10-phenanthroline, EtOH = ethanol） was synthesized by hydrothermal reactions, and its structure was determined by X-ray diffraction. The crystal belongs to the triclinic system, space group Pi with a = 1.15362（1）, b = 1.3655（3）, c = 1.61451（1） nm, α= 72.842（2）, β = 83.259（3）, y = 72.083（2）°, V = 2.3112（6） nm3, Z = 2,μ（MoKa） = 11.71 cm-1, F（000） = 1120, R = 0.0552 and wR = 0.1157 （I 〉 2σ（I））. The two centric zinc（H） ions in the complex locate in a distorted octahedral coordination geometry and a distorted trigonal bipyramid coordination geometry, respectively. Two bridging bidentate carboxyl groups and a μ2-O carboxyl group from three methoxybenzoic acids act as the bridge to link two Zn（Ⅱ） ions. The asymmetric units are connected by π-π packing interactions between aromatic rings to form a three-dimensional supramolecular network. The experimental results show a good fluorescence property for the complex.
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.
基金Project supported by the National Natural Science Foundation of China and partly done in Labotatory of Biomacromolecules, Institute of Biophysics, Academia Sinica, Beijing 100080, PRC.
文摘A series of imidazolate-bridged heteropolynuclear complexes containing Cu2+ or Zn2+ were synthesized and characterized by reflectance spectroscopy, NMR and X-ray diffraction analysis. The bonding nature and the stability of imidazolate bridges in the complexes were studied by ESR spectroscopy, and the catalytic activity of the complexes in dismutation of O-2 was determined by NBT method. Results obtained indicate that the central Cu with N4 and N2O2 square planar or N4O square pyramidal coordination in which there is a weak bond H2O or ClO-4 on axial position, has a comparatively higher activity, but that with N5 square pyramidal having a strong bond axial ligand has almost no activity. Thus the results imply a possible formation of Cu-O-2 intermediate adduct in the catalytic process by Cu, Zn-SOD.
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.
