The cyclic voltammetry and the potential-time curve after galvanostaticelectrolysis were used to study the electrode processes of Cu(II) in CH_3OH solution and DMSOsolution. The electroreduction of Cu(II) to Cu on a P...The cyclic voltammetry and the potential-time curve after galvanostaticelectrolysis were used to study the electrode processes of Cu(II) in CH_3OH solution and DMSOsolution. The electroreduction of Cu(II) to Cu on a Pt electrode proceeds in two steps: Cu(II) + evelence Cu(I); Cu(I) + e velence Cu. The reduction potential of Cu(II) in DMSO solution is morenegative than that in CH_3OH solution, and the diffusion coefficient of Cu(II) ion in DMSO solutionis larger than that in CH_3OH solution because the polarity of DMSO is larger than that of CH_3OHobservably and has a stronger solvating power.展开更多
The adsorption behaviour of Cu2+ onto maghnite was conducted under batch conditions. The effect of time, pH of the dispersion, temperature and initial metal concentration on the adsorption of Cu2+ onto maghnite was in...The adsorption behaviour of Cu2+ onto maghnite was conducted under batch conditions. The effect of time, pH of the dispersion, temperature and initial metal concentration on the adsorption of Cu2+ onto maghnite was investigated. In this study, 94% of Cu(II), was adsorbed on the maghnite clay when the equilibrium was reached at 120 min. The adsorption of Cu2+ was a fast process that followed the pseudo-second-order kinetics. This process could be described by the Langmuir model and gave a maximum Cu2+ adsorption capacity of 21.78 mg/g at 293 K. The thermodynamic parameters such as variation of enthalpy ΔH, variation of entropy ΔS and variation of Gibbs free energy ΔG were calculated from the slope and intercept of lnKd vs. 1/T plots. The adsorption was endothermic reaction. The adsorption process for this natural maghnite is more spontaneous because the values of ΔG are less negative. The results suggested that natural maghnite was suitable as sorbent material for the recovery and adsorption of metal ion from aqueous solutions.展开更多
A new dinuclear copper(II) complex ([Cu(C12H17N2O)(N3)]2, C24H34Cu2N10O2) has been synthesized and characterized by X-ray structure determination. It crystallizes in the monoclinic system, space group P21/c with a =...A new dinuclear copper(II) complex ([Cu(C12H17N2O)(N3)]2, C24H34Cu2N10O2) has been synthesized and characterized by X-ray structure determination. It crystallizes in the monoclinic system, space group P21/c with a = 18.529(4), b = 10.933(2), c = 14.534(3) ?, β = 111.07(3)°, V = 2748(1) ?3, Z = 4, Mr = 621.69, F(000) = 1288, Dc = 1.503 g/cm3 and μ(MoKα) = 1.590 mm?1. The structure was refined to R = 0.0647 and wR = 0.1846 for 4406 observed reflections (I > 2σ(I)). The asymmetric unit comprises two halfmolecules. The complex is a centrosymmetric dimmer in which the copper atoms are penta-coordinated by three coordination atoms from the corresponding tridentate Schiff base ligand and two bridging azide anions. The Cu(II)…Cu(II) average distance is 3.350(1) ?.展开更多
In this study, the ability of red alga (Palmaria palmata) and beer draff (brewery waste) for Cu(II) removal was investigated. The influence of factors, such as pH, initial copper concentrations, and contact time, were...In this study, the ability of red alga (Palmaria palmata) and beer draff (brewery waste) for Cu(II) removal was investigated. The influence of factors, such as pH, initial copper concentrations, and contact time, were also studied. Results showed the adsorption process was strongly dependent on the pH value and initial concentration. The optimum pH value was in the range of 5-6. The Langmuir isotherm model performed better than other models, suggesting monolayer adsorption prevailed in the adsorption process. The theoretical adsorption capacities for Cu(II) were 12.7 mg/g and 9.01 mg/g for red alga and beer draff, respectively. The spectroscopy analyses and desorption studies showed that chemical bonding was the main mechanism in the adsorption process rather than ion exchange. The functional groups of amino, hydroxyl, carboxyl, phenolic hydroxyl, sulphonic group and C–O, –NH stretch might be involved in adsorption. After adsorption, both materials were successfully regenerated by nitric acid at a concentration of 10 mmol/L. Furthermore, the phenomenon that only 7% of adsorbed Cu(II) on red alga and 11% on beer draff were desorbed by sodium chloride solution suggested potential alternative of both materials for the treatment of road runoff containing considerable amounts of de-icing salt.展开更多
A new copper（II）-2,2＇-biimidazole metal-organic POMs-supported compound [Cu（H2biim）2]{[Cu（H2biim）212[H10W12O44]}＇8H2O （H2biim = 2,2＇-biimidazole） has been success- fully synthesized under hydrothermal condi...A new copper（II）-2,2＇-biimidazole metal-organic POMs-supported compound [Cu（H2biim）2]{[Cu（H2biim）212[H10W12O44]}＇8H2O （H2biim = 2,2＇-biimidazole） has been success- fully synthesized under hydrothermal conditions and characterized by single-crystal X-ray diffraction, IR spectroscopy, elemental analysis and TG. The crystal adopts space group Pi with a = 11.800（2）, b = 13.437（3）, c = 13.685（3） A, V = 1922.5（7） A3, D,. = 3.507 g/cm3, C36H62Cu3N24W12O52, M,. = 4059.92, F（000） = 1837,μ = 18.796 mm-1, Z = 1, R = 0.0579 and wR = 0.1465 for 8734 observed reflections （I 〉 2σ（I））. X-ray crystallography analysis exhibits that the title compound consists of one [H10W12044]6- polyanion and three [Cu（H2biim）2] units. And significant π-π stacking interactions and intermolecular O-H-,.O or N-H.＇-O hydrogen-bonding interactions lead to a three-dimensional supramolecular framework. Thermal stability and magnetic property of the complex have also been investigated.展开更多
Adsorption of Cu(II) and Co(II) from aqueous solutions on synthetic nano Fe3O4 has been studied. The effect of experimental parameters such as initial concentration of the metal ions, adsorbent dosage, contact time an...Adsorption of Cu(II) and Co(II) from aqueous solutions on synthetic nano Fe3O4 has been studied. The effect of experimental parameters such as initial concentration of the metal ions, adsorbent dosage, contact time and pH has been investigated. Optimum removal efficiency of Cu(II) ion was found to be 97.8% with the dose rate of 1.07 g/L in 60 minutes at pH = 5.5 and for Co(II) ion, it was found to be 99.2% with the dose rate of2.57 g/L in 10 minutes at pH = 5.4. The removal of Co(II) ions require only 10 minutes with the efficient removal of 99.2%, whereas Cu(II) ions require 60 minutes with the maximum removal of 97.8%. In order to understand the effective removal of Cu(II) and Co(II) ions on Fe3O4, room temperature magnetic measurement was carried out using Vibrational Spectrum Magnetometer (VSM), before and after adsorption with a maximum applied magnetic field of 20,000 G.展开更多
Novel polymeric Cu<sup>2+</sup> complexes derived from the reaction of cyanoacetylhydrazine (<strong>CAH</strong>;<strong>L</strong>) with CuCl<sub>2</sub>•2H<sub>...Novel polymeric Cu<sup>2+</sup> complexes derived from the reaction of cyanoacetylhydrazine (<strong>CAH</strong>;<strong>L</strong>) with CuCl<sub>2</sub>•2H<sub>2</sub>O in different solvents were synthesized and characterized. The isolated solid polymeric complexes were investigated using modern conventional physicochemical and spectral (IR, <sup>1</sup>H-NMR, UV-Vis. ESR, Raman), magnetic and thermal studies. The results revealed that <strong>CAH</strong> behaves in different ways towards the coordination of the Cu<sup>2+</sup> ion. The promotion of solvents to the cyano group was discussed on the basis of the solvent and the Cu<sup>2+</sup> ion used. Magnetic and spectral studies suggest octahedral geometry is proposed for the Cu<sup>2+</sup> complexes. EPR studies indicate the existence of polymeric complexes depending on the results of <i>g</i>-values. The results suggest that the number of copper atoms ranges from three to twelve atoms. The molecular modeling is drawn and some chemical characteristics are calculated such as chemical reactivity and energy components are investigated between the different types of the ligands.展开更多
A new dinuclear copper(II) complex (Cu(C12H17N2O)(NCS)2, C26H34Cu2N6O2S2) has been synthesized and characterized by X-ray structure determination. It crystallizes in the triclinic system, space group P1 with a = 11....A new dinuclear copper(II) complex (Cu(C12H17N2O)(NCS)2, C26H34Cu2N6O2S2) has been synthesized and characterized by X-ray structure determination. It crystallizes in the triclinic system, space group P1 with a = 11.289(2), b = 12.071(2), c = 12.113(2) ?, α = 72.90(3), β = 83.76(3), γ = 65.60(3)°, V = 1436.7(5) ?3, Z = 2, Mr = 653.79, F(000) = 676, Dc = 1.511 g/cm3, μ(MoKα) = 1.660 mm?1, the final R = 0.0334 and wR = 0.0856 for 5047 observed reflections (I > 2σ(I)). The asymmetric unit comprises two half-molecules. The complex is a centrosymmetric dimmer in which each copper(II) is coordinated in the equatorial plane to the N-(salicylidene)-3- dimethylaminopropylamine ligand through the deprotonated phenolic oxygen atom as well as the nitrogen atoms of imine and amine. The fourth coordination site is occupied by the nitrogen atom of NCS?, while the axial one by the symmetrically related phenoxy oxygen of the other monomeric unit. The Cu(II)…Cu(II) average distance is 3.110(1) ?.展开更多
Using two new flexible and functional nitronyl nitroxide radicals as ligands, two copper (II) complexes {[Cu(hfac)<sub>2</sub>]<sub>3</sub>(NITmPhO3Py)<sub>2</sub>}<sub>n...Using two new flexible and functional nitronyl nitroxide radicals as ligands, two copper (II) complexes {[Cu(hfac)<sub>2</sub>]<sub>3</sub>(NITmPhO3Py)<sub>2</sub>}<sub>n</sub> (1) and [Cu(hfac)<sub>2</sub><sub> </sub>(NIToPhO3Py)]<sub>2</sub> (2) (NITmPhO3Py = 2-[(3-methoxy-pyridinyl)phen-3-yl]- 4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide, NIToPhO3Py = 2-[(3-methoxy-pyridinyl)phen-2-ly]-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide, hfac = hexafluoroacetylacetone), have been characterized structurally and magnetically. The X-ray crystal analyses showed that complex 1 displayed a chain polymer structure which formed with {[Cu(hfac)<sub>2</sub>]<sub>3</sub>(NITmPhO3Py)<sub>2</sub>}<sub>n</sub> due to the cross-linking of two cyclic binuclear fragments {[Cu(hfac)<sub>2</sub>]<sub>2</sub>(NITmPhO3- Py)<sub>2</sub>} via the bridging unit [Cu(hfac)<sub>2</sub>];complex 2 presented a binuclear cyclic structure [Cu(hfac)<sub>2</sub>]<sub>2</sub>(NIToPhO3Py)<sub>2</sub>. The magnetic behaviors of the two complexes 1 and 2 have been investigated. Magnetic studies showed that antiferromagnetic interactions dominated in complex 1, while there existed ferromagnetic interactions between Cu(II) and coordinated NO group in complex 2.展开更多
基金This project is financially supported by the Scientific Commission Foundation of Guangzhou City (No. 2001-J-015-01)
文摘The cyclic voltammetry and the potential-time curve after galvanostaticelectrolysis were used to study the electrode processes of Cu(II) in CH_3OH solution and DMSOsolution. The electroreduction of Cu(II) to Cu on a Pt electrode proceeds in two steps: Cu(II) + evelence Cu(I); Cu(I) + e velence Cu. The reduction potential of Cu(II) in DMSO solution is morenegative than that in CH_3OH solution, and the diffusion coefficient of Cu(II) ion in DMSO solutionis larger than that in CH_3OH solution because the polarity of DMSO is larger than that of CH_3OHobservably and has a stronger solvating power.
文摘The adsorption behaviour of Cu2+ onto maghnite was conducted under batch conditions. The effect of time, pH of the dispersion, temperature and initial metal concentration on the adsorption of Cu2+ onto maghnite was investigated. In this study, 94% of Cu(II), was adsorbed on the maghnite clay when the equilibrium was reached at 120 min. The adsorption of Cu2+ was a fast process that followed the pseudo-second-order kinetics. This process could be described by the Langmuir model and gave a maximum Cu2+ adsorption capacity of 21.78 mg/g at 293 K. The thermodynamic parameters such as variation of enthalpy ΔH, variation of entropy ΔS and variation of Gibbs free energy ΔG were calculated from the slope and intercept of lnKd vs. 1/T plots. The adsorption was endothermic reaction. The adsorption process for this natural maghnite is more spontaneous because the values of ΔG are less negative. The results suggested that natural maghnite was suitable as sorbent material for the recovery and adsorption of metal ion from aqueous solutions.
文摘A new dinuclear copper(II) complex ([Cu(C12H17N2O)(N3)]2, C24H34Cu2N10O2) has been synthesized and characterized by X-ray structure determination. It crystallizes in the monoclinic system, space group P21/c with a = 18.529(4), b = 10.933(2), c = 14.534(3) ?, β = 111.07(3)°, V = 2748(1) ?3, Z = 4, Mr = 621.69, F(000) = 1288, Dc = 1.503 g/cm3 and μ(MoKα) = 1.590 mm?1. The structure was refined to R = 0.0647 and wR = 0.1846 for 4406 observed reflections (I > 2σ(I)). The asymmetric unit comprises two halfmolecules. The complex is a centrosymmetric dimmer in which the copper atoms are penta-coordinated by three coordination atoms from the corresponding tridentate Schiff base ligand and two bridging azide anions. The Cu(II)…Cu(II) average distance is 3.350(1) ?.
文摘In this study, the ability of red alga (Palmaria palmata) and beer draff (brewery waste) for Cu(II) removal was investigated. The influence of factors, such as pH, initial copper concentrations, and contact time, were also studied. Results showed the adsorption process was strongly dependent on the pH value and initial concentration. The optimum pH value was in the range of 5-6. The Langmuir isotherm model performed better than other models, suggesting monolayer adsorption prevailed in the adsorption process. The theoretical adsorption capacities for Cu(II) were 12.7 mg/g and 9.01 mg/g for red alga and beer draff, respectively. The spectroscopy analyses and desorption studies showed that chemical bonding was the main mechanism in the adsorption process rather than ion exchange. The functional groups of amino, hydroxyl, carboxyl, phenolic hydroxyl, sulphonic group and C–O, –NH stretch might be involved in adsorption. After adsorption, both materials were successfully regenerated by nitric acid at a concentration of 10 mmol/L. Furthermore, the phenomenon that only 7% of adsorbed Cu(II) on red alga and 11% on beer draff were desorbed by sodium chloride solution suggested potential alternative of both materials for the treatment of road runoff containing considerable amounts of de-icing salt.
基金supported by the Knowledge Innovation Program(No.KJCX2-EW-H01)of Chinese Academy of SciencesNational Natural Science Foundation of China(No.21003125,21073190)Natural Science Foundation of Fujian Province(2010J05040,2010J01057)
文摘A new copper（II）-2,2＇-biimidazole metal-organic POMs-supported compound [Cu（H2biim）2]{[Cu（H2biim）212[H10W12O44]}＇8H2O （H2biim = 2,2＇-biimidazole） has been success- fully synthesized under hydrothermal conditions and characterized by single-crystal X-ray diffraction, IR spectroscopy, elemental analysis and TG. The crystal adopts space group Pi with a = 11.800（2）, b = 13.437（3）, c = 13.685（3） A, V = 1922.5（7） A3, D,. = 3.507 g/cm3, C36H62Cu3N24W12O52, M,. = 4059.92, F（000） = 1837,μ = 18.796 mm-1, Z = 1, R = 0.0579 and wR = 0.1465 for 8734 observed reflections （I 〉 2σ（I））. X-ray crystallography analysis exhibits that the title compound consists of one [H10W12044]6- polyanion and three [Cu（H2biim）2] units. And significant π-π stacking interactions and intermolecular O-H-,.O or N-H.＇-O hydrogen-bonding interactions lead to a three-dimensional supramolecular framework. Thermal stability and magnetic property of the complex have also been investigated.
文摘Adsorption of Cu(II) and Co(II) from aqueous solutions on synthetic nano Fe3O4 has been studied. The effect of experimental parameters such as initial concentration of the metal ions, adsorbent dosage, contact time and pH has been investigated. Optimum removal efficiency of Cu(II) ion was found to be 97.8% with the dose rate of 1.07 g/L in 60 minutes at pH = 5.5 and for Co(II) ion, it was found to be 99.2% with the dose rate of2.57 g/L in 10 minutes at pH = 5.4. The removal of Co(II) ions require only 10 minutes with the efficient removal of 99.2%, whereas Cu(II) ions require 60 minutes with the maximum removal of 97.8%. In order to understand the effective removal of Cu(II) and Co(II) ions on Fe3O4, room temperature magnetic measurement was carried out using Vibrational Spectrum Magnetometer (VSM), before and after adsorption with a maximum applied magnetic field of 20,000 G.
文摘Novel polymeric Cu<sup>2+</sup> complexes derived from the reaction of cyanoacetylhydrazine (<strong>CAH</strong>;<strong>L</strong>) with CuCl<sub>2</sub>•2H<sub>2</sub>O in different solvents were synthesized and characterized. The isolated solid polymeric complexes were investigated using modern conventional physicochemical and spectral (IR, <sup>1</sup>H-NMR, UV-Vis. ESR, Raman), magnetic and thermal studies. The results revealed that <strong>CAH</strong> behaves in different ways towards the coordination of the Cu<sup>2+</sup> ion. The promotion of solvents to the cyano group was discussed on the basis of the solvent and the Cu<sup>2+</sup> ion used. Magnetic and spectral studies suggest octahedral geometry is proposed for the Cu<sup>2+</sup> complexes. EPR studies indicate the existence of polymeric complexes depending on the results of <i>g</i>-values. The results suggest that the number of copper atoms ranges from three to twelve atoms. The molecular modeling is drawn and some chemical characteristics are calculated such as chemical reactivity and energy components are investigated between the different types of the ligands.
文摘A new dinuclear copper(II) complex (Cu(C12H17N2O)(NCS)2, C26H34Cu2N6O2S2) has been synthesized and characterized by X-ray structure determination. It crystallizes in the triclinic system, space group P1 with a = 11.289(2), b = 12.071(2), c = 12.113(2) ?, α = 72.90(3), β = 83.76(3), γ = 65.60(3)°, V = 1436.7(5) ?3, Z = 2, Mr = 653.79, F(000) = 676, Dc = 1.511 g/cm3, μ(MoKα) = 1.660 mm?1, the final R = 0.0334 and wR = 0.0856 for 5047 observed reflections (I > 2σ(I)). The asymmetric unit comprises two half-molecules. The complex is a centrosymmetric dimmer in which each copper(II) is coordinated in the equatorial plane to the N-(salicylidene)-3- dimethylaminopropylamine ligand through the deprotonated phenolic oxygen atom as well as the nitrogen atoms of imine and amine. The fourth coordination site is occupied by the nitrogen atom of NCS?, while the axial one by the symmetrically related phenoxy oxygen of the other monomeric unit. The Cu(II)…Cu(II) average distance is 3.110(1) ?.
文摘Using two new flexible and functional nitronyl nitroxide radicals as ligands, two copper (II) complexes {[Cu(hfac)<sub>2</sub>]<sub>3</sub>(NITmPhO3Py)<sub>2</sub>}<sub>n</sub> (1) and [Cu(hfac)<sub>2</sub><sub> </sub>(NIToPhO3Py)]<sub>2</sub> (2) (NITmPhO3Py = 2-[(3-methoxy-pyridinyl)phen-3-yl]- 4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide, NIToPhO3Py = 2-[(3-methoxy-pyridinyl)phen-2-ly]-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide, hfac = hexafluoroacetylacetone), have been characterized structurally and magnetically. The X-ray crystal analyses showed that complex 1 displayed a chain polymer structure which formed with {[Cu(hfac)<sub>2</sub>]<sub>3</sub>(NITmPhO3Py)<sub>2</sub>}<sub>n</sub> due to the cross-linking of two cyclic binuclear fragments {[Cu(hfac)<sub>2</sub>]<sub>2</sub>(NITmPhO3- Py)<sub>2</sub>} via the bridging unit [Cu(hfac)<sub>2</sub>];complex 2 presented a binuclear cyclic structure [Cu(hfac)<sub>2</sub>]<sub>2</sub>(NIToPhO3Py)<sub>2</sub>. The magnetic behaviors of the two complexes 1 and 2 have been investigated. Magnetic studies showed that antiferromagnetic interactions dominated in complex 1, while there existed ferromagnetic interactions between Cu(II) and coordinated NO group in complex 2.
