Deprotection of t-Butyldimethylsiloxy (TBDMS) Protecting Group with Catalytic Copper (II) Chloride Dihydrate

t-Butyldimethylsilyl (TBDMS) ether can be cleaved upon refluxing in acetone/H2O (95 : 5) in the presence of a catalytic amount of copper (II) chloride dihydrate (5 mmol %).

Oxidation of 2,2'-Dihydroxy-3,3'-di-tert-buty-5,5'-dimethoxyl-biphenyl to 3,3'-Di-tert-butylbiphenyl-2,5,2',5'-diquinone with Copper(Ⅱ)Chloride as Catalyst:Synthesis,Structure and Spectral Properties of Diquinone

Use of free air as oxidant and copper（II）chloride as catalyst,3,3＇-di-tert-butylbi-phenyl-2,5,2＇,5＇-diquinone（BBDQ）was prepared via catalytic oxidation of 2,2＇-dihydroxy-3,3＇-di-tert-butyl-5,5＇-dimethoxy-biphenyl（di-BHA）.The yield of reaction attained 95% and the selectivity for BBDQ was 100%.The single-crystal X-ray diffraction analysis reveals that the dihedral angle between two rings（benzene rings for di-BHA and quinone rings for BBDQ）changes from 89.8 to 45.3o,indicating the steric hindrance effects of methyl disappear in the oxidation process.The crystal structures of di-BHA and BBDQ are further confirmed by their spectral characterizations.The probable mechanism for this oxidation process is also discussed.

Optimal dietary copper requirements and relative bioavailability for weanling pigs fed either copper proteinate or tribasic copper chloride

Background: The objective of this study was to determine the effects of supplementing Cu on growth performance, Cu metabolism and Cu-related enzyme activities of weanling pigs fed diets with two different Cu sources, and to estimate optimal Cu requirements and relative bioavailability from these two sources for pigs.Methods: Weanling pigs were allocated to 14 treatments arranged factorially, including 6 added Cu levels(5, 10,20, 40, 80, 160 mg/kg), and 2 mineral sources(tribasic Cu chloride, TBCC and copper proteinate, Cu Pro), as well as one negative control(0 mg/kg added Cu level) and one maximum allowed level treatment(200 mg/kg TBCC) for the entire 38-d experiment. Growth performance, mineral status and enzyme activities were measured at the end of this study.Results: Increasing levels of Cu showed linear and quadratic responses(P < 0.01) for final BW, ADG and FCR regardless of the sources. Supplementation with TBCC(> 80 mg/kg) and Cu Pro(> 20 mg/kg) significantly decreased(P < 0.05) diarrhea incidence of weanling pigs. There were linear and quadratic increases(P < 0.01) in bile, hepatic,and intestinal Cu concentrations, fecal Cu contents, and plasma enzyme activities(alkaline phosphatase,ceruloplasmin, Cu, Zn-Superoxide dismutase(Cu/Zn SOD), and glutathione peroxidase), whereas plasma malondialdehyde decreased(P < 0.01) linearly and quadratically as dietary Cu level increased. Similarly, pigs fed Cu Pro absorbed and retained more Cu and excreted less Cu than those fed TBCC when supplemented 80 mg/kg and above. Optimal dietary Cu requirements for pigs from 28 to 66 d of age estimated based on fitted broken-line models(P < 0.05) of bile Cu, plasma Cu/Zn SOD and growth performance were 93–140 mg/kg from TBCC, and 63–98 mg/kg from Cu Pro accordingly. According to slope ratios from multiple linear regression, the bioavailability value of Cu Pro relative to TBCC(100%) was 156–263%(P < 0.01).Conclusion: The findings indicated that Cu recommendation from current NRC(5–6 mg/kg) was not sufficient to meet the high requirement of weanling pigs. Cu from Cu Pro was significantly more bioavailable to weanling pigs than TBCC in stimulating growth and enzyme activities, decreasing diarrhea frequency and fecal Cu contents to the environment.

Dissolution kinetics of low grade complex copper ore in ammonia-ammonium chloride solution

The leaching kinetics of Tang-dan refractory low grade complex copper ore was investigated in ammonia-ammonium chloride solution.The concentration of ammonia and ammonium chloride,the ore particle size,the solid-to-liquid ratio and the temperature were chosen as parameters in the experiments.The results show that temperature,concentration of ammonia and ammonium chloride have favorable influence on the leaching rate of copper oxide ores.But,leaching rate decreases with increasing particle size and solid-to-liquid ratio.The leaching process is controlled by the diffusion of the lixiviant and the activation energy is determined to be 23.279 kJ/mol.An equation was also proposed to describe the leaching kinetics.

Real-solution stability diagrams for copper-ammonia-chloride-water system

A comprehensive thermodynamic model,which combined the Helgeson-Kirkham-Flowers(HKF) equation of state for standard-state thermodynamic properties of all species with realistic activity coefficient model developed by BROMLEY,was used to calculate the thermodynamic equilibrium,and a graphical method was developed to construct predominance existence diagrams(PED) for copper-ammonia-chloride in the presence of realistically modeled aqueous solutions.The existence of the different predominant chemical species for Cu(II) predicted by the diagrams was corroborated by spectrophotometrical studies and X-ray diffractometry.The simulated and experimental results indicate that the predominance of a given species in solution strongly depends on the pH value in this system.More quantitative information on real copper hydrometallurgy in the presence of ammonia and chloride can be obtained from these diagrams compared with the conventional predominance existence diagrams.

Preparation of Pure Copper Powder from Acidic Copper Chloride Waste Etchant

为从氯化铜溶液再循环铜的方法被开发。这个过程由铜，纯化和粒子尺寸减小的抽取组成。在第一步，减少的金属碎片被加到废物迷住的酸的氯化铜在聚氯联苯工业生产了获得铜粉。作文分析证明这粉末包含了象 Fe， Ni，和水那样的杂质。那么，弄干并且纯化被使用微波和一个离心分离器执行。从而，铜粉有纯净比 99% 高、球形在形态学的形式。铜粉尺寸被球 milling 减少。

Synthesis, Structure and Fluorescence of a Copper(II) Complex [Cu_2(bipy)_2(Hpht)_2Cl](Hpht)(bipy=2,2'-Bipyridine,H_2pht=o-Phthalic Acid)

The title complex [Cu2(bipy)2(Hpht)2Cl](Hpht) (bipy = 2,2?-bipyridine, H2pht = o-phthalic acid) has been synthesized in the NaOH aqueous solution of CuCl2, Gd(NO3)3, bipy and H2pht, and its crystal structure was determined by single-crystal X-ray diffraction method. It crys- tallizes in triclinic, space group P1, C44H31ClCu2N4O12, Mr = 970.26, a = 8.175(2), b = 16.254(4), c = 16.946(4) ?, α = 62.966(6), β = 84.833(8), γ = 84.348(8)°, V = 1993.4(8) ?3, Z = 2, Dc = 1.616 g/cm3, F(000) = 988 and μ = 1.207 mm-1. The final R = 0.0429 and wR = 0.0843 for 5682 observed reflections with I > 2σ(I). Each copper(II) atom displays a distorted square-pyramidal geometry with two nitrogen atoms of one chelate 2,2?-bipy molecule, two oxygen atoms from two different bridging carboxylate groups of Hpht- and one bridging chloride atom occupying the apical position. The two copper(II) atoms are connected by a μ2-Cl atom and two bridging Hpht- ligands in a syn-syn coordination mode to form an isolated dinuclear unit. The molecular structure is extended to a one-dimensional wavy chain through hydrogen bonds. The title complex exhibits blue fluorescent emission at 443 nm (λex = 372 nm) in the solid state at room temperature.

Adsorption of Lead(II),Copper(II) on tourmaline from Altai mine in China's Sinkiang

Tourmaline from Altai mine in China＇s Sinkiang was used to remove lead （II）, copper （II） from aqueous solution. The results demonstrate that tourmaline contains Na（Mg,V）3AI6（BO3）3Si6Ols （OH）4, NaFe3AI6（BO3）3Si6Ols（OH）4. The data show that Tourmaline from Altai mine in China＇s Sinkiang can be used natural adsorbent for lead （II）, copper （II）.It is observed that the adsorption data fitted to the Langmuir isotherm. Furthermore, both Pb （II） and Cu （II） absorbed by tourmaline and tourmaline were characterized by X-ray diffraction, Laser Raman Spectrum, Fourier transform infrared spectroscopy, X-ray energy dispersive spectrometer, Transmission electron microscopy and Zeta potential.

Synthesis and Crystal Structure of Tri(4-(3-hydroxy2-ethyl-4-pyridinone-1-yl)-aniline Condensation Salicylaldehydato) Monohydratotricopper(II)Dimethylformamide Monohydrate Solvate

The title complex [Cu3L3(H2O)]DMFH2O (H2L = 4-(3-hydroxy-2-ethyl-4- pyridinone-1-yl)-aniline condensation salicylaldehyde) was obtained. The single-crystal X-ray study shows that it is a trinuclear compound [Cu3(C20H15N2O3)3(H2O)]DMFH2O. The coordi- nation sphere about each copper ion in the complex consists of two oxygen atoms from hydroxylpyridinone moiety of one ligand and one oxygen and one nitrogen atoms from salicyladehyde Schiff-base moiety of another ligand arranged in a slightly distorted square planar geometry. Among the three copper ions, one (Cu(2)) is coordinated by the other oxygen atom of water molecule on the fifth coordinate position to form a distorted square pyramid geometry. The crystal is of monoclinic, space group P21/c with a = 12.9202(5), b = 27.197(1), c = 17.0116(7) ? b = 100.588(1), V = 5875.9(4) 3, Z = 4, C63H57N7O12Cu3, Mr = 1294.78, Dc = 1.464 g/cm3, m = 1.146 mm-1, F(000) = 2668, R = 0.0784 and wR = 0.1546 for 6926 observed reflections with I > 2s(I). The differences of coordinate bond lengths are observed between anhydrous and hydrous units: in the former unit, the average bond lengths are 1.978 ?for CuN (azomethine), 1.883 ?for CuO (phenolic) in Schiff-base moiety, 1.959 ?for CuO (keto), and 1.919 ?for CuO (hydroxy) in hydroxypyridinone moiety; while those in the latter are longer with the following corresponding values: 1.985(5), 1.908(5), 1.993(5) and 1.919(4) ? respectively. The Cu(2)O (water) bond length is 2.375(6) ?

Synthesis, Structure and Spectral Characterization of a Discrete Binuclear Copper (II) Complex

A discrete binuclear copper (II) complex containing Cu 2O 2 unit has been synthesized by the reaction of Cu (ClO 4) 2·6H 2O with 2 aminopyridine in the CH 3OH solution and characterized by X ray diffraction study and IR spectroscopy. The crystal is monoclinic, space group: P2 1/n, with unit cell parameters: a=8.2952(2), b=18.4633(3), c=10.5049(2) . β=108.965(1)°, V=1521.56(5) 3, Z=2, C 22 H 30 N 8O 10 Cl 2Cu 2, M r =764.52, D c =1.669 Mg/m 3, F(000)=780, μ (Mo Kα )=8.60, T =293(2)K, final R=0.0623, wR =0.1536 for 2660 observed reflections with I>2.0σ(I ). The centrosymmetric complex Cu 2(CH 3O) 2(C 5H 6N 2) 4(ClO 4) 2 comprises a pair of Cu(II) atoms bridged by two methanoxo and N coordination 2 aminopyridine. The Cu(II)…Cu(II) distance is 3\^002(1).

CATHODIC REDUCTION OF METAL-CHLORIDE COORDINATION IONS

ＣＡＴＨＯＤＩＣＲＥＤＵＣＴＩＯＮＯＦＭＥＴＡＬ－ＣＨＬＯＲＩＤＥＣＯＯＲＤＩＮＡＴＩＯＮＩＯＮＳＺｅｎ，Ｚｈｅｎｏｕ（ＤｅｐａｒｔｍｅｎｔｏｆＡｐｐｌｉｅｄＣｈｅｍｉｓｔｒｙＣｈｅｍｉｓｔｒｙ，ＳｏｕｔｈＣｈｉｎａＵｎｉｖｅｒｓｉｔｙｏｆＴｅｃｈｎ...

Sesame Husk as Adsorbent for Copper(II) Ions Removal from Aqueous Solution

In this study, the adsorption behavior of copper(II) ions from aqueous solutions onto sesame husk (SH) was investigated. The effect of different parameters such as pH, contact time, adsorbent dosage, adsorbate concentration, temperature and agitation speed was studied. Thermodynamic parameters, equilibrium isotherms and kinetic data have been evaluated. The functional groups and surface morphology of SH adsorbent were characterized by FTIR and SEM. Adsorption equilibrium isotherms were expressed by Langmuir, Freundlich and Dubinin-Radushkevich (D-R) adsorption models and it was found that Langmuir adsorption model fits the experimental data better than Freundlich and D-R models. The adsorption can be best described by the pseudo second-order kinetic model.

Novel Screen-Printed All-Solid-State Copper(II)-Selective Electrode for Mobile Environmental Analysis

Based on poly(vinyl chloride) membranes, a novel miniaturized screen-printed all-solid-state copper(II)-selective electrode has been developed for applications in environmental monitoring. Performance and applicability of the ion-selective electrode (ISE) have been proved by potentiometric investigations. Conducting polymers were used as intermediate layers and as solid contacts between the ion-selective membrane and the graphite transducer. The ion-complexing reagent 2-mercapto-benzoxazole was incorporated into poly(vinyl chloride) membranes. In the concentration range 10-6 - 10-2 mol/L, the ISE exhibited a linear Nernstian potential response to copper(II) with an average slope value of 28 mV/decade. The detection limit was 3 × 10-7 mol/L. The electrode exhibits a short response time (<10 s) and can be used in the range of pH = 3 - 7. Selectivity coefficents against certain interfering ions are investigated. The life time of the electrode under laboratory conditions was approximately 12-month. The electrode was applied in the investigation of different aqueous environmental samples and the electrode characteristics were described. The copper(II) ASS electrode has also successfully been used in potentiometric, complexometric titrations with ethylenediaminetetraacetic acid.

Synthesis and Structure of bis(μ-2-aminopyridine N-oxide)-bis[dichlorocopper(II)]

The complex [Cu2（apo）4Cl4]·2H2O （apo=2-aminopyridine N-oxide） was obtained. A single- crystal X-ray study shows that the complex is a binuclear compound （Cu2C20H28Cl4N8O6）. The coordination geometry about each copper atom is best described as a distorted square pyramid. The compound [Cu2（apo）4Cl4]·2H2O belongs to the triclinic system with space group P, lattice constants: a = 7.8550（7）, b = 8.5378（7）, c = 12.082（1） ?, α = 72.807（1）, β = 77.641（1）, γ = 70.800（1）(, V =724.85（11） ?3, Z=1, Mr =745.38, Dc=1.708 g/cm3, μ =1.886mm-1, F（000） =378, R=0.0359, wR2=0.0884 for 2220 reflections with I >2σ（I）. The distances between Cu（II） and O atoms are in the range from 1.934（2） to 2.042（2）?. The distance between two copper atoms Cu-Cu（A） is 3.2978（8） ?. The distances of Cu-Cl（1） and Cu-Cl（2） are 2.2322（9）, 2.5095（10） ?, respectively. There is no evident hydrogen bond between N and Cl.

Disposal of cuprous chloride waste water

The waste water system generated in the process of production of cuprous chloride was studied.The existing forms of copper in the system and the influence of temperature and pH on the existing forms of copper ion were analyzed and determined through calculating the coefficients of copper complex distribution.In the waste water system,the main forms of copper are CuSO4, Cu2 +,CuCl + ,CuCl, 2-and2- 3 CuCl.Temperature has little influence on the distribution coefficient of Cu(Ⅱ),but has significant influence on distribution coefficient of Cu(Ⅰ).With the increase of temperature,the distribution coefficient ofCuCl, 2-increases significantly while the distribution coefficient of2- 3 CuCl decreases.The pH has nearly no influence on the distribution coefficients of various Cu(Ⅰ)-compounds,but has sizable influence on the distribution coefficients of Cu(Ⅱ)-compounds.With the increase of pH,the distribution coefficient of CuSO4(aq)increases while the distribution coefficients of Cu 2+ and CuCl + decrease.According to these results,the anion resin of 201×7 OH-and the cation resin of 732 Na were chosen to dispose the waste water solution of cuprous chloride.Finally,97.9%copper in the waste water is recovered.

Efficient Cleavage of DNA by the Novel Copper (II) Complex Derived From 2,2'-Pyridil Ligand

Copper (II) complex derived from 2, 2'-pyridil ligand has been, demonstrated to cleave efficiently DNA at micromolar concentrations at room temperature and pH 7.25.

Synthesis and Crystal Structure of Copper(II) Complex with N-Acetoxyl-picolinamide

Using Cu(II) as the template, a complex {[Cu2L2(H2O)2]·4H2O}n (L = N-acetoxyl- picolinamide) has been successfully synthesized and characterized by single-crystal X-ray diffrac- tion. The crystal is of monoclinic, space group C2/c, with a = 24.144(5), b = 7.1622(14), c = 17.283(4) ?, C16H24Cu2N4O12, Mr = 591.47, β = 131.73(3)o, V = 2230.3(8) ?3, Z = 4, Dc = 1.761 g/cm3, F(000) = 1208, μ = 1.978 mm?1, R = 0.0400 and wR = 0.1099. The copper (II) ion is five- coordinated with a distorted square pyramidal geometry. The complex can be viewed as a one- dimensional chain structure by carboxylic bridges among copper atoms. In the complex there exist hydrogen bonding interactions to stabilize the structure.

Synthesis and Characterization of Nickel(II) and Copper(II) Complexes with Schiff Base (1R,2R)-(-)-Diaminocyclohexane-N,N'-bis(3-tert-butyl-5-(4'-benzoic acid)-salicylidene)

Two homochiral metallosalen complexes, Ni（salen） （salen = （1R,2R）-（-）-diamino- cyclohexane-N,N′-bis（3-tert-butyl-5-（4′-benzoic acid）-salicylidene） 1 and Cu（salen） 2, have been synthesized and characterized by IR, microanalysis, TGA, powder and single-crystal X-ray crystallography. Both 1 and 2 crystallize in orthorhombic space group P21212 with Z = 4. For 1, a = 12.082（2）, b = 15.447（3）, c = 18.784（4）A^°, V= 3505.7（12）A^°3, Mr = 731.50, Dc = 1.386 g/cm^3, μ = 0.606 mm^-1, F（000） = 1544, the final GOOF = 1.043, R = 0.0496 and wR = 0.1248 for 4791 observed reflections with I 〉 2σ（I）. For 2, a = 12.181（2）, b = 15.501（3）, c = 18.877（4） A^°, V = 3564.3（12）A^°3, Mr = 736.33, Dc = 1.372 g/cm^3, μ = 0.665 mm^-1, F（000） = 1548, the final GOOF = 1.062, R = 0.0575 and wR = 0.1508 for 4562 observed reflections with I 〉 2σ（I）. The crystal structures of 1 and 2 are isostructural with very similar supramolecular structures. An infinite two-dimensional network is generated by hydrogen bonding interactions and intermolecular π…π interactions.