Copper-containing

Copper(II) ions in aqueous solution are readily obtained from any copper-containing material. The reactions with (a) alkali (p. 430), (b) concentrated ammonia (p 413) and (c) hydrogen sulphide (p. 413) provide satisfactory tests for aqueous copper(II) ions. A further test is to add a hexacyanoferrate(II) (usually as the potassium salt) when a chocolate-brown precipitate of copper(II) hexacyanoferrate(II) is obtained ... 

Synthetic phenol capacity in the United States was reported to be ca 1.6 x 10 t/yr in 1989 (206), almost completely based on the cumene process (see Cumene Phenol). Some synthetic phenol [108-95-2] is made from toluene by a process developed by The Dow Chemical Company (2,299—301). Toluene [108-88-3] is oxidized to benzoic acid in a conventional LPO process. Liquid-phase oxidative decarboxylation with a copper-containing catalyst gives phenol in high yield (2,299—304). The phenoHc hydroxyl group is located ortho to the position previously occupied by the carboxyl group of benzoic acid (2,299,301,305). This provides a means to produce meta-substituted phenols otherwise difficult to make (2,306). VPOs for the oxidative decarboxylation of benzoic acid have also been reported (2,307—309). Although the mechanism appears to be similar to the LPO scheme (309), the VPO reaction is reported not to work for toluic acids (310). 

Copper-containing lead alloys undergo less corrosion in sulfuric acid or sulfate solutions than pure lead or other lead alloys. The uniformly dispersed copper particles give rise to local cells in which lead forms the anode and copper forms the cathode. Through this anodic corrosion of the lead, an insoluble film of lead sulfate forms on the surface of the lead, passivating it and preventing further corrosion. The film, if damaged, rapidly reforms. 

Values are minimum for the primary metal and maximum for impurity concentrations. Oxygen-free electrolytic copper containing 0.0001 wt % Bi and Cd and 0.00005 wt % Mn. 

Copper and Copper-Containing Alloys. Either sulfuric or hydrochloric acid may be used effectively to remove the oxide film on copper (qv) or copper-containing alloys. Mixtures of chromic and sulfuric acids not only remove oxides, but also brighten the metal surface. However, health and safety issues related to chromium(VT) make chromic acid less than desirable. 

ALkylamines are corrosive to copper, copper-containing alloys (brass), aluminum, 2inc, 2inc alloy, and galvani2ed surfaces. Aqueous solutions of aLkylamines slowly etch glass as a consequence of the basic properties of the amines in water. Carbon or stainless steel vessels and piping have been used satisfactorily for handling aLkylamines and, as noted above, some aLkylamines can act as corrosion inhibitors in boiler appHcations. 

Acetophenone is separated for hydrogenation to 1-phenylethanol, which is sent to the dehydrator to produce styrene. Hydrogenation is done over a fixed-bed copper-containing catalyst at 115—120°C and pressure of 8100 kPa (80 atm), a 3 1 hydrogen-to-acetophenone ratio, and using a solvent such as ethylbenzene, to give 95% conversion of the acetophenone and 95% selectivity to 1-phenylethanol (186,187). 

In metallurgy, hydrogen sulfide is used to precipitate copper sulfide from nickel—copper-containing ore leach solutions in Alberta, Canada, or to precipitate nickel and cobalt sulfides from sulfuric acid leaching oflaterite ores in Moa Bay, Cuba (120) (see Metallurgy, extractive metallurgy). 

Metallic additions to the melt, usually in the form of copper sulfate, brighten the shade of certain dyes, such as the Bordeaux range made from phenazones and the greens made from the indophenols the metal forms a complex with the dye. However, copper-containing dyes cannot be appHed to material that requires vulcanization. 

Formaldehyde also reacts with butadiene via the Prins reaction to produce pentenediols or their derivatives. This reaction is cataly2ed by a copper-containing catalyst in a carboxyUc acid solution (57) or RuCl (58). The addition of hydrogen also proceeds via 1,2- and 1,4-addition. 

Additions of cadmium (0.05—1.3%) to copper raise the recrystallization temperature and improve the mechanical properties, especially in cold-worked conditions, with relatively Htde reduction in conductivity. Copper containing 0.07% cadmium is used in automotive cooling fins, heavy-duty radiators, motor commutators, and electric terminals. 

The copper contained in the electrolyte, anodes and cathodes, and the normal circulating scrap load is equal to about 10% of the annual copper production of a typical electrorefinery. Some refineries (27) have changed from the traditional 25—30 day anode cycle to a 9—14 day cycle using smaller anodes to reduce the copper inventory in spite of the higher resulting scrap load. 

Copper sulfate is by far the most common algicide. Other copper-containing algicides for use in domestic appHcations such as swimming pools are usually chelated to prevent hydrolysis and precipitation of the copper. 

In 400 ml of dimethylformamide was dissolved 15.0 g of bleomycinic acid (copper-containing form). To the solution kept at 0°C by cooling were added 1.1 ml of N-methylmorpholine and 10.3 g of 6-chloro-1 -p-chlorobenzenesulfonyloxybenzotriazole (CCBT) as an activating compound. The mixture was stirred for 5 minutes at 0°C, then admixed with 5.3 g of N-[(S)-1 -phenylethyl] -1 3-diaminopropane and further stirred for 1 hour. 

By similar treatment, 280 mg of the unreacted bleomycinic acid (copper-containing form) were recovered. 

In 200 ml of distilled water was dissolved 10.0 g of the NK631 dihydrochloride (copper-containing form). The solution was poured into a column containing 600 ml of Amberlite XAD-2 packed in distilled water. The column was washed successively with 2 liters of an aqueous solution containing 5% of EOTA-Na, 2.5 liters of a 5% aqueous sodium sulfate solution, and 630 ml of distilled water. 

It is also of interest to note that Wranglen considers that the decrease in the corrosion rate of steel in the atmosphere and the pitting rate in acid and neutral solution brought about by small alloying additions of copper is due to the formation of CU2S, which reduces the activity of the HS and Scions to a very low value so that they do not catalyse anodic dissolution, and a similar mechanism was put forward by Fyfe etal. to explain the corrosion resistance of copper-containing steels when exposed to industrial atmospheres. 

Tarpaulins are sometimes treated with copper-containing preservatives and water leached from these has been found to cause corrosion of underlying aluminium sheets. 

Degreasing by cathodic treatment in a hot alkaline solution is desirable when the copper contains inclusions of cuprous oxide. Pickling may be carried out in either cold 50% hydrochloric acid or 20% v/v nitric acid, or in hot (70°C) 6% v/v sulphuric acid containing 1.5% w/w sodium dichromate. 

Method for performing a stress-corrosion cracking test of low copper containing Al-Zn-Mg alloys in boiling 6% sodium chloride solution... 

Analogous side-chain oxidations occur in various biosynthetic pathways. The neurotransmitter norepinephrine, for instance, is biosynthesized from dopamine by a benzylic hydroxylation reaction. The process is catalyzed by the copper-containing enzyme dopamine /3-monooxygenase and occurs by a radical mechanism. A copper-oxygen species in the enzyme first abstracts the pro-R benzylic hydrogen to give a radical, and a hydroxyl is then transferred from copper to carbon. 

---