The new ligand bis-（1,4-sodium thiolactate） butane （L）-O2CCH3S-（CH2）4SCHCH3CO2- has been prepared from the reaction of disodium salt of thiolactic acid and 1,4-dichlorobutane, while the disodium thiolactate was ...The new ligand bis-（1,4-sodium thiolactate） butane （L）-O2CCH3S-（CH2）4SCHCH3CO2- has been prepared from the reaction of disodium salt of thiolactic acid and 1,4-dichlorobutane, while the disodium thiolactate was prepared instanteously through the reaction of thiolactic acid with NaOH. Mono and dinuclear complexes were obtained by direct reaction of the above ligands with H[AuCI4] in 1 ： 1, 2：1, 1：2, 2：2 and 3：1 ligands to metal molar ratio. The prepared complexes were characterized by elemental analysis, spectral studies FTIR （Fourier transform Infrared） and UV-Vis, magnetic measurement, conductivity measurement and IHNMR for the ligand （L） and some of the complexes. The conductance data indicate that the complexes of the formulas Na[Au（SCH3CHCOO）2], Na[Au（SCH3CHCOO）（OOCCHCH3SH）2] and [Au（L）]Cl are 1：1 electrolyte. Electronic spectra and magnetic moment values indicate the presence of square planner geometry around Au（III） ions.展开更多
Thermodynamic properties and electrochemical behaviors of gold and its associated elements, such as silver, copper, nickel and iron, in various complex agent solutions were studied. Within CS（NH2）2, S2O2-3 and SCN- ...Thermodynamic properties and electrochemical behaviors of gold and its associated elements, such as silver, copper, nickel and iron, in various complex agent solutions were studied. Within CS（NH2）2, S2O2-3 and SCN- systems, alkaline thiourea is the optimal nontoxic lixiviating agent substituting cyanide from the viewpoint of thermodynamics. The electrochemical study indicates that the anodic dissolution current densities of gold are 2.616, （1.805,） 1.267, 1.088, 0.556, and 0.145 mA·cm-2 respectively in the solutions of cyanide, alkaline thiourea containing Na2SiO3, SCN-, acidic thiourea, alkaline thiourea and thiosulfate at the potential of 0.500 V. Comparing various lixiviating agents, the alkaline thiourea solution containing Na2SiO3 is of prominent selectivity in leaching gold, in the potential range from 0.500 to 0.600 V, which is most efficient for leaching gold selectively instead of cyanide. The effect on leaching gold is similar to that in the cyanide system.展开更多
The synthesis,structure and luminescent property of a tetranuclear gold（Ⅰ）complex with doubly bridging diethyldithiocarbamate（Et2dtc）and 1,1-bis（diphenylphosphino）ethene（（Ph2P）2C=CH2）are described.The compl...The synthesis,structure and luminescent property of a tetranuclear gold（Ⅰ）complex with doubly bridging diethyldithiocarbamate（Et2dtc）and 1,1-bis（diphenylphosphino）ethene（（Ph2P）2C=CH2）are described.The complex crystallizes in monoclinic space group C2/c with a=26.785（7）,b=25.654（6）,c=12.277（3）A,β=106.879（5）°,V=8073（4）A^3,Z=8,C31H32Au2F6NO3P2S2Sb,Mr=1222.32,Dc=2.011 g/cm^3,F（000）=4592,Rint=0.0529,T=293（2）K,μ=8.157 mm^（-1）,the final R=0.0464 and wR=0.1444 for 5804 observed reflections with I〉2σ（Ⅰ）.The intramolecular and intermolecular Au¨Au distances are 2.8670（9）and 3.2367（9）A,respectively.Weak emission appears at 517 nm at room temperature in the solid state.展开更多
We have prepared supramolecular systems of chiral Schiff base Ni(II), Cu(II), Zn(II) complexes and colloidal gold nanoparticles (AuNP) of 10 nm diameters. They demonstrated that direct adsorption of chiral Schiff base...We have prepared supramolecular systems of chiral Schiff base Ni(II), Cu(II), Zn(II) complexes and colloidal gold nanoparticles (AuNP) of 10 nm diameters. They demonstrated that direct adsorption of chiral Schiff base metal complex on the surface of AuNP owing to observation of clear induced CD spectra for the first time. We observed and discussed induced CD bands on AuNP from chiral Schiff base Ni(II), Cu(II), Zn(II) complexes.展开更多
The electronic structure and electronic absorption spectra of binuclear Au(Ⅰ) complexes with bidentate phophines and a bidentate ylid ligand have been studied using quasirelativistic pseudopotential ab initio cal...The electronic structure and electronic absorption spectra of binuclear Au(Ⅰ) complexes with bidentate phophines and a bidentate ylid ligand have been studied using quasirelativistic pseudopotential ab initio calculations at the HF and MP2 levels by the LANL2DZ basis sets. The electronic properties of the spectral transition and Au(Ⅰ)—Au(Ⅰ) interaction were also discussed.展开更多
The electrochemistry of di-μ-oxo-dimanganese complex was investigated. It was found that no redox peak was observed in the cyclic voltammogram (CV) of the complex at the bare gold electrode, but at thiouracil-modifie...The electrochemistry of di-μ-oxo-dimanganese complex was investigated. It was found that no redox peak was observed in the cyclic voltammogram (CV) of the complex at the bare gold electrode, but at thiouracil-modified gold electrode, a pair of redox peaks were observed showing that thiouracil can promote the proton-coupled electron transfer reaction of the complex.展开更多
A rapid synthesis of size-controlled gold nanoparticles was proposed.The method is based on the sensitive intramolecular photoreduction reaction of Fe（Ⅲ）-EDTA complex in chloroacetic acid-sodium acetate buffer solu...A rapid synthesis of size-controlled gold nanoparticles was proposed.The method is based on the sensitive intramolecular photoreduction reaction of Fe（Ⅲ）-EDTA complex in chloroacetic acid-sodium acetate buffer solution,where Fe（Ⅱ）-EDTA complex generated by photo-promotion acts as a reductant of AuCl-4 ions.Gold nanoparticles formed were stabilized by EDTA ligand or other protective agents added.As a result,well-dispersed gold nanoparticles with an average diameter range of 6.7 to 50.9 nm were obtained.According to the characterizations by the UV spectrum and TEM,the intramolecular charge transfer of the excited states of complex Fe（Ⅲ）-EDTA and the mechanism of forming gold nanoparticles were discussed in detail.展开更多
Two new isomeric Au complexes, Au（PPh3）（bmt）, have been synthesized via the reaction of Au（PPh3）CI with 2-benzimidazolethiol （Hbmt） in dichloromethane （CH2Cl2） solution. Their crystal structures were determi...Two new isomeric Au complexes, Au（PPh3）（bmt）, have been synthesized via the reaction of Au（PPh3）CI with 2-benzimidazolethiol （Hbmt） in dichloromethane （CH2Cl2） solution. Their crystal structures were determined by elemental analysis and single-crystal X-ray diffraction studies. Complex 1 crystallizes in the monoclinic system, space group C2/c with a = 19.589（2）, b = 21.1368（15）, c = 23.424（2） A, β = 108.346（4）°, V= 9206.1（14） A3, Mr = 1216.85, Dc = 1.756 g/cm3, μ = 6.566 mm^-1, F（000） = 4704, Z = 8, the final R = 0.0563 and wR = 0.1028 for 8125 reflections with I 〉 2σ（I）. Complex 2 crystallizes in the monoclinic system, space group P21/n with a = 9.627（3）, b = 21.384（8）, c = 22.308（8） A, β = 92.068（6）°, V= 4590（3） A3, Mr = 1216.85, Dc = 1.761 g/cms, μ = 6.585 mm^-1, F（000） = 2352, Z = 4, the final R = 0.0500 and wR = 0.0883 for 10477 reflections with I 〉 2σ（i）. X-ray diffraction studies reveal that complexes 1 and 2 both feature a 1D chain along the a axis.展开更多
The complexation between gold and silica was experimentally confirmed and calibrated at 200℃:Thermodynamic calculations show that AuH3SiO40 would be far more abundant than AnCl2 un-der physicochemical conditions of g...The complexation between gold and silica was experimentally confirmed and calibrated at 200℃:Thermodynamic calculations show that AuH3SiO40 would be far more abundant than AnCl2 un-der physicochemical conditions of geological interest, suggesting that silica is much more importantthan chloride as ligands for gold transport. In systems containing both sulfur and silica, AuH3SiO40would be increasingly more important than Au (HS)2 as thc proportion of SiO2 in the system in -creases.The dissolution of gold in aqueous SiO2 soluhons can be described by the reachon:which indicates that SiO2 precipitahon is an effective mechanism governing gold deposihon, and thusexplains the close association of silicification and gold mineralization.展开更多
The interactions of acetone molecules with clusters of Au3 and Au5 are investigated by using a density functional theory （DFT） within a generalized gradient approximation （GGA）. The geometries, adsorption energies...The interactions of acetone molecules with clusters of Au3 and Au5 are investigated by using a density functional theory （DFT） within a generalized gradient approximation （GGA）. The geometries, adsorption energies and deformation electron density distributions are used to analyse these interactions. The present calculations show that more than one acetone molecules can be adsorbed onto small gold clusters, and this adsorption is different from that of single molecule absorption. The coordination number of the adsorption site on the gold cluster is the dominant factor responsible for the strength of the interactions. The effects of the Au O bond lengths in the complexes on adsorption energies between Au clusters and acetone molecules are also examined.展开更多
The Au\|SiO\-2 and Sn\|SiO\-2 complexes have been experimentally calibrated at varying temperature, silica concentration and pH: Au\+++H\-3SiO\+-\-4AuH\-3SiO\-4lgK=-1.65436+9611.21/T Sn\+\{4+\}+4H\-3SiO\+-\-4Sn(H\-3Si...The Au\|SiO\-2 and Sn\|SiO\-2 complexes have been experimentally calibrated at varying temperature, silica concentration and pH: Au\+++H\-3SiO\+-\-4AuH\-3SiO\-4lgK=-1.65436+9611.21/T Sn\+\{4+\}+4H\-3SiO\+-\-4Sn(H\-3SiO\-4)\-4lgK\-\{200℃\}=42.73Compared with Au\|Cl, Au\|HS and Sn\|OH complexes, AuH\-3SiO\-4 and Sn(H\-3SiO\-4)\-4 complexes can be recognized as the dominant transport forms in Si\|bearing solutions under pH and Eh conditions of general interest. The decrease of SiO\-2 concentration and oxygen fugacity would reverse the direction of dissolution\|complexing reactions, resulting in the precipitation of gold and silica, as well as cassiterite and silica. This study illustrates the significance of SiO\-2\|complexation in hydrothermal solutions for gold, tin and other metallizations.展开更多
文摘The new ligand bis-（1,4-sodium thiolactate） butane （L）-O2CCH3S-（CH2）4SCHCH3CO2- has been prepared from the reaction of disodium salt of thiolactic acid and 1,4-dichlorobutane, while the disodium thiolactate was prepared instanteously through the reaction of thiolactic acid with NaOH. Mono and dinuclear complexes were obtained by direct reaction of the above ligands with H[AuCI4] in 1 ： 1, 2：1, 1：2, 2：2 and 3：1 ligands to metal molar ratio. The prepared complexes were characterized by elemental analysis, spectral studies FTIR （Fourier transform Infrared） and UV-Vis, magnetic measurement, conductivity measurement and IHNMR for the ligand （L） and some of the complexes. The conductance data indicate that the complexes of the formulas Na[Au（SCH3CHCOO）2], Na[Au（SCH3CHCOO）（OOCCHCH3SH）2] and [Au（L）]Cl are 1：1 electrolyte. Electronic spectra and magnetic moment values indicate the presence of square planner geometry around Au（III） ions.
文摘Thermodynamic properties and electrochemical behaviors of gold and its associated elements, such as silver, copper, nickel and iron, in various complex agent solutions were studied. Within CS（NH2）2, S2O2-3 and SCN- systems, alkaline thiourea is the optimal nontoxic lixiviating agent substituting cyanide from the viewpoint of thermodynamics. The electrochemical study indicates that the anodic dissolution current densities of gold are 2.616, （1.805,） 1.267, 1.088, 0.556, and 0.145 mA·cm-2 respectively in the solutions of cyanide, alkaline thiourea containing Na2SiO3, SCN-, acidic thiourea, alkaline thiourea and thiosulfate at the potential of 0.500 V. Comparing various lixiviating agents, the alkaline thiourea solution containing Na2SiO3 is of prominent selectivity in leaching gold, in the potential range from 0.500 to 0.600 V, which is most efficient for leaching gold selectively instead of cyanide. The effect on leaching gold is similar to that in the cyanide system.
基金financial supports from the NNSFC(20931006,U0934003,and 91122006)the NSF of Fujian Province(2011J01065)
文摘The synthesis,structure and luminescent property of a tetranuclear gold（Ⅰ）complex with doubly bridging diethyldithiocarbamate（Et2dtc）and 1,1-bis（diphenylphosphino）ethene（（Ph2P）2C=CH2）are described.The complex crystallizes in monoclinic space group C2/c with a=26.785（7）,b=25.654（6）,c=12.277（3）A,β=106.879（5）°,V=8073（4）A^3,Z=8,C31H32Au2F6NO3P2S2Sb,Mr=1222.32,Dc=2.011 g/cm^3,F（000）=4592,Rint=0.0529,T=293（2）K,μ=8.157 mm^（-1）,the final R=0.0464 and wR=0.1444 for 5804 observed reflections with I〉2σ（Ⅰ）.The intramolecular and intermolecular Au¨Au distances are 2.8670（9）and 3.2367（9）A,respectively.Weak emission appears at 517 nm at room temperature in the solid state.
文摘We have prepared supramolecular systems of chiral Schiff base Ni(II), Cu(II), Zn(II) complexes and colloidal gold nanoparticles (AuNP) of 10 nm diameters. They demonstrated that direct adsorption of chiral Schiff base metal complex on the surface of AuNP owing to observation of clear induced CD spectra for the first time. We observed and discussed induced CD bands on AuNP from chiral Schiff base Ni(II), Cu(II), Zn(II) complexes.
文摘The electronic structure and electronic absorption spectra of binuclear Au(Ⅰ) complexes with bidentate phophines and a bidentate ylid ligand have been studied using quasirelativistic pseudopotential ab initio calculations at the HF and MP2 levels by the LANL2DZ basis sets. The electronic properties of the spectral transition and Au(Ⅰ)—Au(Ⅰ) interaction were also discussed.
文摘The electrochemistry of di-μ-oxo-dimanganese complex was investigated. It was found that no redox peak was observed in the cyclic voltammogram (CV) of the complex at the bare gold electrode, but at thiouracil-modified gold electrode, a pair of redox peaks were observed showing that thiouracil can promote the proton-coupled electron transfer reaction of the complex.
基金Supported by the Natural Science Foundation of Yunnan Province,China(No.2000E0008Z).
文摘A rapid synthesis of size-controlled gold nanoparticles was proposed.The method is based on the sensitive intramolecular photoreduction reaction of Fe（Ⅲ）-EDTA complex in chloroacetic acid-sodium acetate buffer solution,where Fe（Ⅱ）-EDTA complex generated by photo-promotion acts as a reductant of AuCl-4 ions.Gold nanoparticles formed were stabilized by EDTA ligand or other protective agents added.As a result,well-dispersed gold nanoparticles with an average diameter range of 6.7 to 50.9 nm were obtained.According to the characterizations by the UV spectrum and TEM,the intramolecular charge transfer of the excited states of complex Fe（Ⅲ）-EDTA and the mechanism of forming gold nanoparticles were discussed in detail.
基金supported by the Youth Science Foundation of Jining University(2009QNKJ07)
文摘Two new isomeric Au complexes, Au（PPh3）（bmt）, have been synthesized via the reaction of Au（PPh3）CI with 2-benzimidazolethiol （Hbmt） in dichloromethane （CH2Cl2） solution. Their crystal structures were determined by elemental analysis and single-crystal X-ray diffraction studies. Complex 1 crystallizes in the monoclinic system, space group C2/c with a = 19.589（2）, b = 21.1368（15）, c = 23.424（2） A, β = 108.346（4）°, V= 9206.1（14） A3, Mr = 1216.85, Dc = 1.756 g/cm3, μ = 6.566 mm^-1, F（000） = 4704, Z = 8, the final R = 0.0563 and wR = 0.1028 for 8125 reflections with I 〉 2σ（I）. Complex 2 crystallizes in the monoclinic system, space group P21/n with a = 9.627（3）, b = 21.384（8）, c = 22.308（8） A, β = 92.068（6）°, V= 4590（3） A3, Mr = 1216.85, Dc = 1.761 g/cms, μ = 6.585 mm^-1, F（000） = 2352, Z = 4, the final R = 0.0500 and wR = 0.0883 for 10477 reflections with I 〉 2σ（i）. X-ray diffraction studies reveal that complexes 1 and 2 both feature a 1D chain along the a axis.
文摘The complexation between gold and silica was experimentally confirmed and calibrated at 200℃:Thermodynamic calculations show that AuH3SiO40 would be far more abundant than AnCl2 un-der physicochemical conditions of geological interest, suggesting that silica is much more importantthan chloride as ligands for gold transport. In systems containing both sulfur and silica, AuH3SiO40would be increasingly more important than Au (HS)2 as thc proportion of SiO2 in the system in -creases.The dissolution of gold in aqueous SiO2 soluhons can be described by the reachon:which indicates that SiO2 precipitahon is an effective mechanism governing gold deposihon, and thusexplains the close association of silicification and gold mineralization.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.10674114 and 10974078)
文摘The interactions of acetone molecules with clusters of Au3 and Au5 are investigated by using a density functional theory （DFT） within a generalized gradient approximation （GGA）. The geometries, adsorption energies and deformation electron density distributions are used to analyse these interactions. The present calculations show that more than one acetone molecules can be adsorbed onto small gold clusters, and this adsorption is different from that of single molecule absorption. The coordination number of the adsorption site on the gold cluster is the dominant factor responsible for the strength of the interactions. The effects of the Au O bond lengths in the complexes on adsorption energies between Au clusters and acetone molecules are also examined.
文摘The Au\|SiO\-2 and Sn\|SiO\-2 complexes have been experimentally calibrated at varying temperature, silica concentration and pH: Au\+++H\-3SiO\+-\-4AuH\-3SiO\-4lgK=-1.65436+9611.21/T Sn\+\{4+\}+4H\-3SiO\+-\-4Sn(H\-3SiO\-4)\-4lgK\-\{200℃\}=42.73Compared with Au\|Cl, Au\|HS and Sn\|OH complexes, AuH\-3SiO\-4 and Sn(H\-3SiO\-4)\-4 complexes can be recognized as the dominant transport forms in Si\|bearing solutions under pH and Eh conditions of general interest. The decrease of SiO\-2 concentration and oxygen fugacity would reverse the direction of dissolution\|complexing reactions, resulting in the precipitation of gold and silica, as well as cassiterite and silica. This study illustrates the significance of SiO\-2\|complexation in hydrothermal solutions for gold, tin and other metallizations.
