Complex salt Co_2Cl_5(py)_5 (py=pyridine) was obtained by the reaction of CoCl_2·6H_2O with Bu_4NMnO_4 in pyridine in the presence of benzoic acid. It is monoclinic and crystallizes in space group P2_1/n, fw=690....Complex salt Co_2Cl_5(py)_5 (py=pyridine) was obtained by the reaction of CoCl_2·6H_2O with Bu_4NMnO_4 in pyridine in the presence of benzoic acid. It is monoclinic and crystallizes in space group P2_1/n, fw=690.64, a=28.652(5), b=14.108(4), c=7.424(3) ;β=90.09(1); V=3001(2)~3; Z=4, Dc=1.53g/cm^3. Final R factor is 0.041. The structure consists of a discrete cation [Co~ⅢCl_2(py)_4]^+ and an anion [Co~Ⅱ Cl_3(py)]^-. The Co~Ⅲ ion is coordinated by two Cl^- and four pyridine nitrogen atoms to form an octahedral geometry, and Co~Ⅱ is coordinated by three Cl^- and one pyridine nitrogen atom to form the apices of a tetrahedron. The variable-temperature magnetic susceptility measurement shows no magnet-exchange interaction between Co~Ⅲ and Co~Ⅱ ions.展开更多
Alkali salts of tungsten based heteropoly acids with different central atom such as P, Si and Co were prepared and evaluated for transes- terification of both edible and non-edible oils to their corresponding fatty ac...Alkali salts of tungsten based heteropoly acids with different central atom such as P, Si and Co were prepared and evaluated for transes- terification of both edible and non-edible oils to their corresponding fatty acid methyl esters. The catalyst of sodium salt of tungstic acid with Co as central atom （Na5CoW12O40） showed optimum activity towards transesterification compared with other heteropoly tungstates. The catalysts activities were correlated with the observed physico-chemical characteristics derived from FT-infrared （FT-IR）, X-ray diffraction （XRD）, temperature-programmed desorption of ammonia （NH3-TPD） and carbon dioxide （CO2-TPD）. The Na5CoW12O40 catalyst exhibiting high activity even at 65 ℃ is due to the presence of strong acidic as well as basic sites. The disclosed catalyst is tolerable towards water and free fatty acids present in the oils. The influence of catalyst loading, reaction time and reaction temperature is studied to optimize the reaction parameters.展开更多
A novel salt-assisted low temperature solid state method using CoCl2.6H2O, FeCl3.6H2O and NaOH as precursor and using NaCI as a dispersant to synthesize high surface area CoFe2O4 nanoparticles, has been investigated. ...A novel salt-assisted low temperature solid state method using CoCl2.6H2O, FeCl3.6H2O and NaOH as precursor and using NaCI as a dispersant to synthesize high surface area CoFe2O4 nanoparticles, has been investigated. The effects of the molar ratio of added salt and calcination temperature on the characteristics of the products were investigated by X-ray diffraction （XRD）, transmission electron microscopy （TEM）, vibrating sample magnetometer （VSM） and Brunauer, Emmett and Teller （BET） surface area analysis. Results showed that the introduction of leachable inert inorganic salt as a hard agglomeration inhibitor in the mixture precursor led to the formation of high dispersive CoFe2O4 nanoparticles; and the increase in specific surface area from 28.28 to 73.97 m^2/g, and the saturation magnetization is 84.6 emu/g.展开更多
The electrochemical behaviour of Eu￣(3+) on cobalt electrode in KCl-ErCl3 melt has been studied by means of cyclic voltammetry and open-circuit potentiometry. The experimental results show that the Er-Co alloy is for...The electrochemical behaviour of Eu￣(3+) on cobalt electrode in KCl-ErCl3 melt has been studied by means of cyclic voltammetry and open-circuit potentiometry. The experimental results show that the Er-Co alloy is formed at first and then metallic erbium is deposited when the Er￣(3+) is reduced on the cobalt electrede. The conditions for preparing Er-Co alloy by cobalt consumable cathode have been investigated. The Er-Co alloy contained 92 wt% erbium is obtained. It is consist of Er_3Co and Er. The recovery of erbium is more than 90% and the current efficiency is near 80%.展开更多
The Co（II） complex I and ammonium salt II were synthesized from the direct reaction of 1,2-ethylenediamine and cobaltous acetate tetrahydrate and manganese acetate tetrahydrate in anhydrous ethanol. Treatment of N,N...The Co（II） complex I and ammonium salt II were synthesized from the direct reaction of 1,2-ethylenediamine and cobaltous acetate tetrahydrate and manganese acetate tetrahydrate in anhydrous ethanol. Treatment of N,N＇-bis（salicylidene）ethylenediamine with Cu（OAc）2·H2O results in the formation of Cu（II） complex III. C14H37CoNaO8 （I）： triclinic, space group P1, a = 8.6296（12）, b = 12.0291（17）, c = 12.1108（17） A, α = 75.335（2）, β = 69.991（2）, γ = 72.248（2）°, V= 1109.4（3） A3, Z = 2, ρcaloa = 1.342 g/cm3, the final R= 0.0342 for 4817 observed reflections with I 〉 2σ（I） and Rw = 0.1263 for all data. C6H16N204 （II）： space group P1, a = 5.5513（10）, b = 5.5589（11）, c = 7.4437（14） A, α = 94.332（4）, β = 104.497（4）, γ = 103.487（4）°,V= 214.06（7） A3, Z = 1, ρcalcd = 1.398 g/cm3, the final R = 0.0431 for 829 observed reflections with I〉 2σ（I） and Rw = 0.1263 for all data. C14H37CuN40 （III）, space group P21/n, a = 9.050（9）, b = 18.434（17）, c = 11.659（11） A, β = 107.134（19）°, V= 1859（3） A3, Z = 4, ρcalcd =1.443 g/cm3, the final R = 0.0616 for 3308 observed reflections （O 〉 2σ（I）） and Rw = 0.1229 for all data. Their structures were all determined by X-ray diffraction, elemental analysis and IR.展开更多
文摘Complex salt Co_2Cl_5(py)_5 (py=pyridine) was obtained by the reaction of CoCl_2·6H_2O with Bu_4NMnO_4 in pyridine in the presence of benzoic acid. It is monoclinic and crystallizes in space group P2_1/n, fw=690.64, a=28.652(5), b=14.108(4), c=7.424(3) ;β=90.09(1); V=3001(2)~3; Z=4, Dc=1.53g/cm^3. Final R factor is 0.041. The structure consists of a discrete cation [Co~ⅢCl_2(py)_4]^+ and an anion [Co~Ⅱ Cl_3(py)]^-. The Co~Ⅲ ion is coordinated by two Cl^- and four pyridine nitrogen atoms to form an octahedral geometry, and Co~Ⅱ is coordinated by three Cl^- and one pyridine nitrogen atom to form the apices of a tetrahedron. The variable-temperature magnetic susceptility measurement shows no magnet-exchange interaction between Co~Ⅲ and Co~Ⅱ ions.
文摘Alkali salts of tungsten based heteropoly acids with different central atom such as P, Si and Co were prepared and evaluated for transes- terification of both edible and non-edible oils to their corresponding fatty acid methyl esters. The catalyst of sodium salt of tungstic acid with Co as central atom （Na5CoW12O40） showed optimum activity towards transesterification compared with other heteropoly tungstates. The catalysts activities were correlated with the observed physico-chemical characteristics derived from FT-infrared （FT-IR）, X-ray diffraction （XRD）, temperature-programmed desorption of ammonia （NH3-TPD） and carbon dioxide （CO2-TPD）. The Na5CoW12O40 catalyst exhibiting high activity even at 65 ℃ is due to the presence of strong acidic as well as basic sites. The disclosed catalyst is tolerable towards water and free fatty acids present in the oils. The influence of catalyst loading, reaction time and reaction temperature is studied to optimize the reaction parameters.
基金supported by the National Natural Sci-ence Foundation of China under grant No. 50602024the Youth Foundation of North University of China
文摘A novel salt-assisted low temperature solid state method using CoCl2.6H2O, FeCl3.6H2O and NaOH as precursor and using NaCI as a dispersant to synthesize high surface area CoFe2O4 nanoparticles, has been investigated. The effects of the molar ratio of added salt and calcination temperature on the characteristics of the products were investigated by X-ray diffraction （XRD）, transmission electron microscopy （TEM）, vibrating sample magnetometer （VSM） and Brunauer, Emmett and Teller （BET） surface area analysis. Results showed that the introduction of leachable inert inorganic salt as a hard agglomeration inhibitor in the mixture precursor led to the formation of high dispersive CoFe2O4 nanoparticles; and the increase in specific surface area from 28.28 to 73.97 m^2/g, and the saturation magnetization is 84.6 emu/g.
文摘The electrochemical behaviour of Eu￣(3+) on cobalt electrode in KCl-ErCl3 melt has been studied by means of cyclic voltammetry and open-circuit potentiometry. The experimental results show that the Er-Co alloy is formed at first and then metallic erbium is deposited when the Er￣(3+) is reduced on the cobalt electrede. The conditions for preparing Er-Co alloy by cobalt consumable cathode have been investigated. The Er-Co alloy contained 92 wt% erbium is obtained. It is consist of Er_3Co and Er. The recovery of erbium is more than 90% and the current efficiency is near 80%.
文摘The Co（II） complex I and ammonium salt II were synthesized from the direct reaction of 1,2-ethylenediamine and cobaltous acetate tetrahydrate and manganese acetate tetrahydrate in anhydrous ethanol. Treatment of N,N＇-bis（salicylidene）ethylenediamine with Cu（OAc）2·H2O results in the formation of Cu（II） complex III. C14H37CoNaO8 （I）： triclinic, space group P1, a = 8.6296（12）, b = 12.0291（17）, c = 12.1108（17） A, α = 75.335（2）, β = 69.991（2）, γ = 72.248（2）°, V= 1109.4（3） A3, Z = 2, ρcaloa = 1.342 g/cm3, the final R= 0.0342 for 4817 observed reflections with I 〉 2σ（I） and Rw = 0.1263 for all data. C6H16N204 （II）： space group P1, a = 5.5513（10）, b = 5.5589（11）, c = 7.4437（14） A, α = 94.332（4）, β = 104.497（4）, γ = 103.487（4）°,V= 214.06（7） A3, Z = 1, ρcalcd = 1.398 g/cm3, the final R = 0.0431 for 829 observed reflections with I〉 2σ（I） and Rw = 0.1263 for all data. C14H37CuN40 （III）, space group P21/n, a = 9.050（9）, b = 18.434（17）, c = 11.659（11） A, β = 107.134（19）°, V= 1859（3） A3, Z = 4, ρcalcd =1.443 g/cm3, the final R = 0.0616 for 3308 observed reflections （O 〉 2σ（I）） and Rw = 0.1229 for all data. Their structures were all determined by X-ray diffraction, elemental analysis and IR.
