Synthesis,Structure and Properties of a Novel Copper(Ⅱ)-2,2'- biimidazole Complex-supported Compound:[Cu(H_2biim)_2]{[Cu(H_2biim)_2 ]_2[H_(10)W_(12)O_(44)]}·8H_2O

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.

Crystal Growth of Cu6(Ge,Si)6O18·6H2O and Assignment of UV-VIS Spectra in Comparison to Dehydrated Dioptase and Selected Cu(II) Oxo-Compounds Including Cuprates

Low-dimensional quantum spin systems with the Cu2+ central ion are still in the focus of experimental and theoretical research. Here is reported on growth of mm-sized single-crystals of the low-dimensional S = 1/2 spin compound Cu6(Ge,Si)6O18·6H2O by a diffusion technique in aqueous solution. A route to form Si-rich crystals down to possible dioptase, the pure silicate, is discussed. Motivated by previously reported incorrect assignments of UV-VIS spectra, the assignment of dd excitations from such spectra of the hexahydrate and the fully dehydrated compound is proposed in comparison to dioptase and selected Cu(II) oxo-compounds using bond strength considerations. Non-doped cuprates as layer compounds show higher excitation energies than the title compound. However, when the antiferromagnetic interaction energy as Jz·ln(2) is taken into account for cuprates, a single linear relationship between the Dqe excitation energy and equatorial Cu(II)-O bond strength is confirmed for all compounds. A linear representation is also confirmed between 2A1g energies and a function of axial and equatorial Cu-O bond distances if auxiliary axial bonds are used for four-coordinated compounds. The quotient Dt/Ds of experimental orbital energies deviating from the general trend to smaller values indicates the existence of H2O respectively Cl−axial ligands in comparison to oxo-ligands, whereas larger Dt/Dqe values indicate missing axial bonds. The quotient of the excitation energy 2A1g by 2·2Eg-2B2g allows checking for correctness of the assignment and to distinguish between axial oxo-ligands and others like H2O or Cl−.

STUDIES ON THE PROPERTIES OF SCHIFF BASE TYPE ARYLMERCURY COMPOUNDS.II ^(199)Hg NMR SPECTRA OF MERCURATED DERIVATIVES OF SUBSTITUTED BENZYLIDENEANILINES

^(199)Hg NHR spectra of 18 Schiff base type arylmercury compounds have been studied.It was further confirmed that in the molecule of XC_6H_4CH=NC_6H_3-2-HgC1-4-CH_3 there exists an intramolecular N→Hg coordination via a four-membered ring.For the series of XC_6H_4CH=NC_6H_3-2-HgCl-4-CH_3(X is a para-or mera-substituent),there is a good linear correlation between δ^(199)Hg and Hammett's o constants.The influence of substituents of C-pheny1 ring on the δ ^(199)Hg can be explained in terms of the intramolecular N→Hg coordination.

Cu(II)在对甲苯磺酸铜+DMSO中的电还原

制备了对甲苯磺酸铜并首次用于电化学实验.差示扫描量热和热重曲线测定表明,对甲苯磺酸铜结晶容易脱除全部结晶水,无水盐在空气中不潮解.用循环伏安曲线、计时电流曲线和恒电流电解后的电位-时间曲线研究Cu(Ⅱ)在二甲基亚砜(DMSO)溶液中的电还原.结果表明,Cu(II)电还原为Cu的反应分两步进行,其中第一步是可逆过程.测定了Cu(II)在DMSO溶液中的扩散系数.

Effect of uniform magnetic field on crystallization of intermetallic compound layers between Cu and liquid SnZn alloys

Crystallization of intermetallic compound layer between Cu and SnZn alloy under uniform magnetic field was studied. The effect of magnetic field density on the growth behavior of the intermetallic layer such as microstructure, crystal orientation and composition was analyzed by scanning electron microscopy, X-ray diffraction and electron-probe microanalysis, respectively. Compared with the intermetallic layer without magnetic field, 0.1 T of magnetic flux density decreases the layer thickness. However, further increasing magnetic flux density promotes the layer growth. Application of magnetic field also changes the crystal orientation of intermetallic layer, but has no obvious influence on the layer composition. This phenomenon can be attributed to the role of thermo-electromagnetic convection and Lorentz force on the Cu dissolution as well as the accumulation of Cu solute at the interface front.

泉州湾滩涂沉积物对Cu(II)的吸附实验

研究了Cu(II) 在泉州湾滩涂沉积物上的吸附行为。探讨了pH和温度对吸附作用的影响,测定了其吸附等温线。实验结果表明,常温下Cu(II) 在泉州湾滩涂沉积物上的吸附平衡时间约需3.5 小时;吸附量随pH的升高先增大而后减少,pH=6.0左右时达最大;吸附量随温度的升高而增大;其吸附行为可以很好地用Langmuir型吸附等温线来描述。并在此基础上初步探讨了Cu(II)在泉州湾滩涂沉积物上的吸附机理。

Synthesis, crystal structure and magnetic properties of novel copper compound Cu(phen)(m-CBA)_2

A novel compound Cu（phen）（m-CBA）2 was synthesized with m-chlorobenzoic acid（m-CBA）, 1,10-phenanthroline（phen） and Cu（OAc）2·H2O. It was characterized by IR, UV, elemental analyses and X-ray crystallography. It crystallizes in the monoclinic crystal system with C2/c space group, a=2.9699（4） nm, b=1.15452（2） nm, c=1.5335（2） nm, β=111.118（2）°, V=4.905 1（1） nm3, Z=8, F（000）=2 328, R1=0.072 8, wR2=0.223 4 [I2σ（I）]. Structure analysis shows that the copper center coordinates with two nitrogen atoms from one 1,10-phenanthroline molecule, two oxygen atoms from two m-chlorobenzoic acid molecules, giving a distorted squared planar coordination geometry. This novel compound shows paramagnetic interactions between copper centers.

Microstructure and properties of Al/Cu bimetal in liquid-solid compound casting process

A Ni-P coating was deposited on Cu substrate by electroless plating and the Al/Cu bimetal was produced by solid？liquid compound casting technology. The microstructure, mechanical properties and conductivity of Al/Cu joints with different process parameters （bonding temperature and preheating time） were investigated. The results showed that intermetallics formed at the interface and the thickness and variety increased with the increase of bonding temperature and preheating time. The Ni？P interlayer functioned as a diffusion barrier and protective film which effectively reduced the formation of intermetallics. The shear strength and conductivity of Al/Cu bimetal were reduced by increasing the thickness of intermetallics. In particular, the detrimental effect of Al2Cu phase was more obvious compared with the others. The sample preheated at 780 ℃ for 150 s exhibited the maximum shear strength and conductivity of 49.8 MPa and 5.29×10^5 S/cm, respectively.

不锈钢表面Al/Cu涂层制备与第一性原理计算

为了研究Al/Cu涂层中金属间化合物的生成顺序和形成机理,在304不锈钢基体表面制备了Al/Cu涂层。对试样进行热处理使得Al/Cu涂层原位反应生成金属间化合物,随后测试了涂层的高温抗氧化性能。采用第一性原理计算Al-Cu金属间化合物的焓、熵、吉布斯自由能和热容等数据。将热力学和扩散动力学相结合,提出有效生成自由能模型来预测化合物在Al/Cu界面的生成顺序。结果表明:Al/Cu涂层中首先形成Al_(2)Cu相,在Al/Cu界面处出现了AlCu相,加热时间增加至20 h后出现了富Cu的Al_(4)Cu_(9)相。由第一性原理计算得出,Al-Cu金属间化合物的形成顺序为Al_(2)Cu→AlCu→Al_(4)Cu_(9),与实验结果一致。此外,氧化实验结果表明,涂层具有良好高温抗氧化性能。

Electrochemical behavior of Cu(II) reduced in CH3OH and DMSO

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.

Adsorption of Cu(II) on maghnite from aqueous solution: Effects of pH, initial concentration, interaction time and temperature

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.

Interfacial microstructure and mechanical behavior of Mg/Cu bimetal composites fabricated by compound casting process

Mg/Cu bimetal composites were prepared by compound casting method, and the microstructure evolution, phase constitution and bonding strength at the interface were investigated.It is found that a good metallurgical bonding can be achieved at the interface of Mg and Cu,which consists of two sub-layers,i.e.,layer I with 30μm on the copper side composed of Mg2Cu matrix phase, on which a small amount of dendritic MgCu2 phase was randomly distributed;layerⅡ with 140μm on the magnesium side made up of the lamellar nano-eutectic network Mg2Cu+(Mg) and a small amount of detached Mg2Cu phase. The average interfacial shear strength of the bimetal composite is measured to be 13 MPa.This study provides a new fabrication process for the application of Mg/Cu bimetal composites as the hydrogen storage materials.

Synthesis and Crystal Structure of a Dinuclear Cu(II) Complex with Tridentate Schiff Base and Azido Bridge

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) ?.

Gapped Spin-1/2 Spinon Excitations in a New Kagome Quantum Spin Liquid Compound Cu_3Zn(OH)_6FBr

We report a new kagome quantum spin liquid candidate CuaZn（OH）6FBr, which does not experience any phase transition down to 50inK, more than three orders lower than the antiferromagnetic Curie-Weiss temperature （-200 K）. A clear gap opening at low temperature is observed in the uniform spin susceptibility obtained from 19F nuclear magnetic resonance measurements. We observe the characteristic magnetic field dependence of the gap as expected for fractionalized spin-1/2 spinon excitations. Our experimental results provide firm evidence for spin fractionalization in a topologically ordered spin system, resembling charge fraetionalization in the fractional quantum Hall state.

Thermodynamic description of the ternary compounds in the Cu-In-Se system

A set of thermodynamic descriptions of the temary compounds （mainly α-CulnSe2, δ-CulnSe2, Culn3Se5 and CulnsSe8） in the Cu-In-Se system was established by adopting sub-lattice model. The model parameters are carefully evaluated by integrating the experimental data of thermodynamic properties, phase equilibrium and theoretical calculation of formation energies of different point defects. The evaluated Gibbs energies of the compounds reasonably agree with that estimated from EMF experiment and ab initio calculation. The calculated phase relationships in the Cu-In-Se system are in accord with the experimental phase diagrams. The obtained standard enthalpy of formation of CulnSe2 is close to that reported in the literatures.

Atomic Absorption and Vibrational Spectral Magnetic Studies on the Removal of Cu(II) and Co(II) Ions Using Synthetic Nano Adsorbent Fe₃O₄

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.

Biosorption of Cu(II) Ions from Aqueous Solution by Red Alga (<i>Palmaria Palmata</i>) and Beer Draff

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.

Comparative Studies of Some Novel Cu(II) Polymeric Complexes Derived from Cyanoacetylhydrazine (CAH;L). The Role of Solvents Used on the Structure and Geometry of the Isolated Cu²⁺Complexes

Novel polymeric Cu2+ complexes derived from the reaction of cyanoacetylhydrazine (CAH;L) with CuCl2•2H2O in different solvents were synthesized and characterized. The isolated solid polymeric complexes were investigated using modern conventional physicochemical and spectral (IR, 1H-NMR, UV-Vis. ESR, Raman), magnetic and thermal studies. The results revealed that CAH behaves in different ways towards the coordination of the Cu2+ ion. The promotion of solvents to the cyano group was discussed on the basis of the solvent and the Cu2+ ion used. Magnetic and spectral studies suggest octahedral geometry is proposed for the Cu2+ complexes. EPR studies indicate the existence of polymeric complexes depending on the results of g-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.

不同温度下制备的椰壳生物炭对水中Cu(II)的吸附研究

化工业的快速兴起,使含有农药、油漆以及化肥等有害废水和废渣大量排放,导致环境中的铜污染进一步恶化。因此,要降低和消除环境中过量的金属铜,吸附是一种行之有效的技术手段。生物炭因其制备费用低,吸附性能好以及对环境友好等特点而被广泛研究使用。本实验以我国海南省来源广泛的椰壳作为原材料,分别在500℃、600℃和700℃条件下制备生物炭(分别记为T500、T600和T700)。利用三种温度制备的椰壳生物炭研究不同初始浓度、生物炭投加量、溶液初始pH值以及吸附时间等因素对水中Cu(II)的吸附特征。研究结论如下:1) 三种温度下制备的椰壳生物炭对水中Cu(II)都具有较好的吸附效果,在相同条件下,三种生物炭的吸附能力:T700 】T600 】T500。2) 在水中Cu(II)初始浓度为60 mg/L,投加量为0.2 g,pH为4,吸附时间为3 h时,T700的最大吸附量达到8.6833 mg/g。

MXene/PMS利用EDTA-Cu催化降解EDTA-Cd性能与机理

在不添加低价态过渡金属条件下,MXene/PMS利用乙二胺四乙酸铜(EDTA-Cu)实现了乙二胺四乙酸镉(EDTA-Cd)的高效降解和Cd的回收.EDTA-Cd和总Cd在30min内的去除率达到80%和95%.增加MXene、PMS和Cu^(2+)浓度均显著增强了EDTA-Cd和总Cd的去除.反应体系主要活性物种是羟基自由基(HO^(·))和硫酸根自由基(SO_(4)^(·-)).在p H值3.0~9.0范围内保持了优异的性能,对Cl^(-)、HCO_(3)^(-)、HPO_(4)^(2-)和腐殖酸具有良好的耐受性.MXene活化PMS将EDTA-Cu氧化破络,释放出游离Cu离子,并触发Cu(Ⅱ)/Cu(Ⅰ)价态循环,强化了PMS的活化,从而实现了EDTA-Cu/Cd的高效降解.MXene对Cu和Cd离子具有优异的吸附能力,实现了重金属的回收.本研究利用重金属络合物本身含有的过渡金属,开发了一种同步实现重金属络合物氧化破络与重金属回收的方法.