Cupric compounds

For reaction with hydrogen haUdes, the substitution reaction with haUde ion easily occurs when a cuprous or cupric compound is used as the catalyst (23) and yields a halogenated aHyl compound. With a cuprous compound as the catalyst at 18 °C, the reaction is completed in 6 h. Zinc chloride is also a good catalyst (24), but a by-product, diaHyl ether, is formed. 

Cupri-. cupric, copper(II). -azetst, n. cupric acetate, copper(II) acetate, -carbonat, n. cupric carbonate, copper(II) carbonate, -chlorid, n. cupric chloride, copper(II) chloride. -hydroxyd, n. cupric hydroxide, cop-per(II) hydroxide. -ion, n. cupric ion, copper(II) ion. -ozalat, n. cupric oxalate, copper(II) oxalate, -oxyd, n. cupric oxide, copper(II) oxide. -salz, n. cupric salt, copper(II) salt, -suifat, n. cupric sulfate. copper(II) sulfate, -sulfid, n. cupric sulfide, copper(II) sulfide, -verbihdung, /. cupric compound, copper(II) compound, -wein-saure, /. cupritartaric acid. 

Kupfer-oxydverbindung, /. cupric compound, copper(II) compound. -pecherz,n. = Kupferbraun. -platte, /. copper plate, copperplate. 

Coppers second oxidation state (+2) forms cupric compounds, also referred to as copper(II), which are more stable than copper(l) compounds. For example, copper in both oxidation states can combine with fluorine for copper(I) or cuprous fluoride, Cu" " + F CuF and for copper(ll) or cupric fluoride, Cu " " + 2F —> CuF. ... 

As previously mentioned, copper has two oxidation states. Compounds formed by +1 copper are known as cuprous compounds, and those with a +2 oxidation state are cupric compounds. Both oxidation states may be found in related compounds. 

Stirring the mixture in the air simplifies the workup procedure because cuprous complexes are oxidized to cupric compounds that are highly soluble in water or the aqueous ammonia workup medium of this experiment. 

Cupric Compounds. Same as Copper (II) Compounds. See in this volume, p C 515-R... 

Add copper sulphate solution and then excess caustic soda solution. Solution turns violet, but precipitation of copper hydrate does not take place. On warming, reduction of the cupric compound occurs and red cuprous oxide is precipitated (Trammer s test). 

When solutions of cupric compounds are acidified with hydrochloric acid, a red film of metallic copper is deposited on a bright untarnished surface of metallic iron. An excess of 6 A ammonia, added to a solution of a cupric salt, produces first a blue precipitate and then a deep blue colored solution. Solutions of cupric salts yield with potassium ferrocyanide TS a red-brown precipitate, insoluble in diluted acids. 

Transition metals have partially filled d orbitals, and therefore their compounds are obvious candidates for Jahn-Teller systems. Let us consider an example from among the much studied cupric compounds [64], Suppose that the Cu2+ ion with its electronic configuration is surrounded by six ligands in an octahedral arrangement. We have already seen (Table 6-10 and Figure 6-36) that the d orbitals split into a triply (t2g) and a doubly (eg) degenerate level in an octahedral environment. For Cu2+ the only possible electronic configuration is t e. ... 

The cupric compounds, CuX2, show a marked resemblance to those of the metals of Group II. and to those of other metals characterized by their bivalency, an example being the similarity of constitution and isomorphism of cupric sulphate with the sulphates of magnesium and zinc, and with the ous sulphates of iron, nickel, cobalt, and manganese. All these sulphates combine with those of the alkali-metals to form... 

Valency and Ions.—Copper is usually considered to exhibit univalency in the cuprous compounds and bivalency in the cupric compounds. Its univalency in the cuprous compounds accords with the position of the metal in the periodic system, and is exemplified by the resemblance of the cuprous halides to the halides of silver and univalent gold, and also by the isomorphism of cuprous sulphide and silver sulphide. The bivalency of the atom in the cupric compounds is in agreement with the properties of many of its derivatives, a typical example being the isomorphism of cupric sulphate with the sulphates of ferrous iron, zinc, magnesium, and manganese. 

Besides these two main classes of copper compounds, there appear to be other types of copper derivatives, among them oxides of the formulae Cu40, CusO, Cu203, and Cu02. The cuprous ion, Cu, corresponds with the cuprous compounds, which are colourless in aqueous solution. The cupric ion, Cu, corresponds with the cupric compounds, which have a blue, green, violet, yellow, or brown colour in solution. 

Cuprous sulphate dissolves in concentrated hydrochloric acid and in concentrated ammonium hydroxide. The ammoniacal solution yields a colourless, crystalline compound, Cu2S04,4NH3,H20, decomposed by water into metallic copper and an ammoniacal cupric compound.1 Cuprous sulphate is also dissolved to a slight extent by glacial acetic acid. The deep-violet solution thus produced is rapidly oxidized by air to a blue liquid, from which crystals of an acid cupric acetate are deposited.2... 

When the catalyst is cupric chloride the reaction does not usually show high selectivity, since large quantities ofby-products are formed, such as methyl ether and methyl chloride. This does not occur when the reaction system consists of the reduction of a cupric compound, eg. Cu(OCHi)CI obtained by oxidizing a cuprous CuCl compound in methanol. A comparison of reduction tests performed in cupric chloride and CufOCH lCI under the same reaction conditions shows that the reactivity of the two systems is basically different (Table II). 

The principal compounds of copper are the cupric compounds, containing bipositive copper. The cupric ioriy Cu++ (or Cu (H20)4++), occurs in many salts. The cuprous ion, Cu", is unstable, and the cuprous c6 Aii)07uuls, except the very insoluble ones, are easily oxidized. 

Ores of copper native copper, cuprite, chalcocite, chalcopyrite, malachite, azurite. Metallurgy of ores containing native copper, oxide and carbonate ores, sulfide ores. Gangue, flux, flotation, roasting of ores, matte, blister copper. Cupric compounds copper sulfate (blue vitriol, bluestone), Bordeaux mixture, cupric chloride, cupric bromide, cupric hydroxide. Test for cupric ion with Fehling s solution. Cuprous compounds cuprous chloride, cuprous bromide, cuprous iodide, cuprous oxide. Covalent-bond structure of cuprous compounds. 

Susceptible positions of organic compounds can be directly acyloxylated " by ferf-butyl peroxyesters, the most frequently used being acetic and benzoic (R = Me or Ph). " The reaction requires a catalyst (cuprous ion is the actual catalyst, but a trace is all that is necessary, and such traces are usually present in cupric compounds, so that these are often used) and without it is not selective. Susceptible positions are similar to those in 14-6 benzylic, allylic, and the a position of ethers and sulfides. Terminal alkenes are substituted almost entirely in the 3 position, that is, with only a small amount of allylic rearrangement, but internal alkenes generally give mixtures containing a large amount of allylic-shift product. If the reaction with alkenes is carried out in an excess of... 

The possible structures for hexagonal and cubic close packing are listed, with examples, in Table 10.15, which corresponds to the portion of the more general Table 4.6 (p. 142) for one-half octahedral holes occupied . In the ideal c.p. structures the coordination group around a metal atom is an octahedral group (of 4 OH + 2 X or 5 OH + X) in which the M—0 and M—X bonds have their normal lengths. As in the case of other cupric compounds there are distortions of the... 

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