Copper preparation

Kupfer-pol, m. Elec.) copper pole (positive pole), -praparat, n. copper preparation, -probe,/, copper assay, test for copper, -raf-fination, /. copper refining, -ranch, m. copper smoke, copper fumes white vitriol,... 

SURFACE IMPROVEMENT OF NANO COPPER PREPARATION OF CU-AG DOUBLE METAL POWDER... 

Copper in contact mass plays the role of a catalyst. Pure copper is obtained by the electrolysis of copper sulfate. For direct synthesis, we use the copper of two brands, Mo and Mi with 99.95-99.9% of Cu. The total impurity content (Bi, Sb, As, Fe, Ni, Pb, etc.) should not exceed 0.05-0.1%. To ensure high activity of contact mass, it is necessary to use copper powders with complex surfaces. Good results in direct synthesis are also obtained when using fine copper prepared by the mechanical spraying of copper powder or deposition of copper from copper salts. 

As has been mentioned in 1, smooth surfaces of copper, including those deposited electrolytically, reduced copper mirrors, and polished surfaces were quite inactive (a, i) a minute trace of activity only was occasionally detected in commercial copper gauze, but copper prepared by thermal decomposition of either cupric or cuprous oxides, or copper salts of mono- and dibasic fatty acids, by condensation on china-clay rods2 from the vapour (in nitrogen, to prevent oxidation), or by stirring up the atoms of copper into open formation by heating in ammonia at 820°, was active (t). 

Agency for Toxic Substances and Disease Registry (ATSDR). 1990. Toxicological profile for copper. Prepared by Syracuse Research Corporation for ATSDR. U.S. Public Health Service under Contract 88-0608-2. ATSDR/TP-90-08. Atlanta, GA U.S. Department of Health and Human Services, Public Health Service. 

Finely divided copper has been used as a reducing agent for Fe(III). Activated copper,prepared by reducing copper(II) oxide with hydrogen, has been used to displace cadmium but not zinc from a cyanide solution. In cyanide solution, copper is a strong reducing agent (.F° = —1.09 V). Its formal potential hes between those of zinc (—1.26 V) and cadmium (—0.90 V) and several heavy metals (Pb, Bi, Sn, Ag, Hg) are displaced from solution. 

The precursor mixed oxide of Cu60gLn(N03) can be prepared with copper and metal ions where the oxide of the metal ion express InjOs type crystal structure [11,12]. Therefore, the metal ion of Ln can be changed to In and some lanthanide ions (Ho to Lu). The catalytic activity of Ho, Er and Yb contained copper prepared from the corresponding mixed oxides are listed in Table 3. From the results in Table 3, the catalytic activity is changed by changing the oxide and ytterbium oxide contained copper show the highest activity. There are various factors, e.g. the nature and condition of the precursor oxide, to explain the difference. However, the difference cannot be explained further from the results in this work. 

Reactive metals in the copper anode, such as iron and zinc, are also oxidized at the anode and enter the solution as Fe and Zn + ions. They are not reduced at the cathode, however. The less electropositive metals, such as gold and silver, are not oxidized at the anode. Eventually, as the copper anode dissolves, these metals fall to the bottom of the cell. Thus, the net result of this electrolysis process is the transfer of copper from the anode to the cathode. Copper prepared this way has a purity greater than 99.5 percent (Figure 20.7). 

Fortunately, Werner Hangarter, a German physician who was Head of Medicine at the University of Kiel, was just beginning his research with a new copper preparation, Permalon, in 1950. Permalon was a Cu(II)-salicylate-containing preparation developed by Hangarter in collaboration with Reiser of the Albert Chemical Company. 

Figure 40 Ribbon diagram of the homotrimer of nitrate reductase from Alcaligenes xylosoxidans (PDB-code 10E1). The singie monomers are coiored iight biue, iemon, and raspberry. T1Cu, type-1 copper T2Cu, type-2 copper prepared with PyMOL (W. L. DeLano, Paio Aito, 2003).

Organocopper reagents can be made directly from the bromides and active Cu, which is prepared by reduction of CuCN nLiX with lithium naphthalenide. Copper prepared from Cul PR, (R=Bu, Ph) is most suitable for intramolecular reaction of bromoaryl epoxides to give dihydrobenzofurans. 

Bulk Copper Preparation of bulk copper surfaces (samples may consist of rods, foils, or disks) includes polishing, rinsing, and in some cases degreasing. When samples are used for SERS, a roughening step is added. This was achieved by... 

Joseph KS, Pradeep B (1994) Oxide films of copper prepared by the oxidation of copper sulfide films. Pram J Phys 42 41-47... 

Colloidal copper, prepared by borohydride reduction of copper(II) salts in the presence of protective polymers and with particle sizes of 5.0-15.0 nm (depending on preparation details), is an active catalyst for the hydration of unsaturated nitriles to their corresponding unsaturated amides with 100% selectivity. [53, 268] The copper particle size was unaffected by the catalytic process. The catidyst performance was optimized in a detailed study of the effects of polymer molecular weight, polymer/metal ratio, and the chemical constitution of the polymer. [268, 269]... 

CtiS04 is oftai added to water to stop algae or fungal growth, and other copper preparations are used to spray or dust plants to protect them from lower organisms and insects. Copper compounds are not generally toxic to human beings, except in massive quantities. Our daily diet normally includes from 2 to 5 mg of copper. 

Cross-coupling with Organocopper Reagents. HexasUylbi-cyclo[2.2.2]octan-l-yl copper, prepared from tbe treatment of hexasilylbicyclo[2.2.2]octan-l-yl lithium with copper(T) iodide in THF, reacts with (iodoethynyl)trimethylsilane (eq 6) in the presence of pyridine to afford the alkynyl-substituted polysilacage compound. ... 

Lithioorganocuprates. Lithium bis(trimethylsilylpropynyl)-copper, prepared by addition of lithium trimethylsilylpropyne to copper(I) iodide, has been used as a nucleophilic source of the trimethylsilylpropynyl group (eq 5). Chemoselective 1,2-addition resulted in a 90% isolated yield of the desired secondary alkynyl alcohol (eq 5) use of the corresponding lithium or bromo-magnesium acetylides resulted in substantial recovery of allenic products. ... 

Winkler method). Add a mixture of 86 g of copper (11) chloride and 17 g of finely divided metallic copper, prepared by the reduction of 8 g tol2 g of cupper (11) oxide with hydrogen gas, to a solution of HCl, made by diluting 650 mL of concentrated HCl with 325 mL of distilled water. After the mixture has been added slowly and with frequent stirring, a spiral of copper wire is suspended in the bottle, reaching all the way to the bottom. The solution is ready to use when the solution becomes colorless. 

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