Cuprous cation

Thus, all copper salts give an explosive reaction with calcium carbide. This is due to the formation of explosive copper acetylide, which is formed from cupric or cuprous cation and the acetylene formed. 

Cu + 1 and +2 Cu+ copper (I) cation or cuprous cation Cu2+ copper (II) cation or cupric cation... 

Figure 19.3 Interfacial defect generation/annihilation reactions that are postulated to occur in the growth of anodic barrier sulfide films according to the Point Defect Model. s cation vacancy on the metal sublattice of the barrier layer Cuf = cuprous cation interstitial Cuq = cuprous cation in cation site on the metal sublattice of the CU2S barrier layer V" = sulfur vacancy on the anion sublattice of the barrier layer Sj = sulfur anion on the anion sublattice of the barrier layer Cu = cuprous cation in solution.

Thiocyanates are rather stable to air, oxidation, and dilute nitric acid. Of considerable practical importance are the reactions of thiocyanate with metal cations. Silver, mercury, lead, and cuprous thiocyanates precipitate. Many metals form complexes. The deep red complex of ferric iron with thiocyanate, [Fe(SCN)g] , is an effective iadicator for either ion. Various metal thiocyanate complexes with transition metals can be extracted iato organic solvents. 

Copper(I) oxide [1317-39-1] is 2lp-ty e semiconductor, Cu2 0, in which proper vacancies act as acceptors to create electron holes that conduct within a narrow band in the Cu i7-orbitals. Nickel monoxide [1313-99-17, NiO, forms a deficient semiconductor in which vacancies occur in cation sites similar to those for cuprous oxide. For each cation vacancy two electron holes must be formed, the latter assumed to be associated with regular cations ([Ni " h = Semiconduction results from the transfer of positive charges from cation to cation through the lattice. Conduction of this type is similar... 

These figures furnish a handy summary of solubility behavior. We see from Figure 10-5A that few chlorides have low solubilities. The few that do contain cations of metals clustered toward the right side of the periodic table (silver ion, Ag+, cuprous ion, Cu+, mercurous ion, HgJ2, and lead ion, Pb+2) but they do not fall in a single column. This irregularity is not un-... 

Prior to analysis, solutions from seven-day T/D tests on cuprous oxide (Cu20) and nickel metal powder (Ni) were passed through a column with iminodiacetate functional groups using an ammonium acetate buffer. The alkali and alkali earth metals are not bound to the column thereby separating the cations associated with the saltwater matrix from the transition metals of interest which are subsequently eluted with nitric acid and analysed by ICP-AES (inductively-coupled plasma-atomic emission spectrometry). 

Snider and Kwon use either cupric triflate and cuprous oxide or ceric ammonium nitrate and sodium bicarbonate as single-electron oxidants to convert d,s- and ,C-unsaturated enol silyl ethers 9 stereoselectively to the tricyclic ketones 14 in excellent yields [83, 84]. Based on comparison with other experimental data and literature results, the authors try to distinguish between several possible intermediates and propose the following mechanism with a very electrophilic radical cation 10 as the key intermediate. 

Cuprous and ferrous salts are preferable. Sometimes, a transition metal salt is deliberately added to a mixtnre of a snbstrate and a persnlfate salt (Dobson et al. 1986). The free or metal-coordinated sulfate anion-radical reacts with an organic snbstrate, giving rise to a snbstrate cation-radical (Minisci et al. 1983, Itahara et al. 1988, Telo and Vieira 1997). The substrate cation-radical is often able to expel a proton and transform into the corresponding radical. The latter regenerates the initial metallic ion. The whole reaction becomes a catalytic one with respect to the metal. 

The mechanism by which a nucleophile displaces the diazonium group depends on the nucleophile. While some displacements involve phenyl cations, others involve radicals. Nucleophiles, e.g. CN , Cl and Br , replace the diazonium group if the appropriate cuprous salt is added to the solution containing the arene diazonium salt. The reaction of an arene diazonium salt with cuprous salt is known as a Sandmeyer reaction. 

Mazumder A, Gupta M, Perrin DM, Sigman DS, Rabinovitz M, Pommier Y. Inhibition of human immunodeficiency virus type 1 integrase by a hydrophobic cation The phenanthroline-cuprous complex. AIDS Res Human Retro 1995 11 115-125. 

Concerted One-Electron Reductions. Reduction of 02 in the presence of excess zinc cation [Znu(bpy)2+], (tetraphenylporphinato)iron(III) ion [(H20)+FemTPP], and cuprous ion [Cu MeCN)/] results in formation of metal-dioxygen adducts. Figures 9.13 and 9.14 illustrate the cyclic voltam-mograms for (FemTPP)Cl and tCuI(MeCN)4]C104, respectively, in the absence and presence of 02. Reaction schemes for the three metal-02 systems are outlined ... 

Some substances manifest both electronic and electrolytic conductance at the same time. Among such conductors are some metal compounds such as solid silver sulphide, cuprous oxide, zinc oxide, cuprous chloride and similar substances. A special group includes solutions of alkali- and alkaline-earth metals in amines, namely in liquid ammonia, where appart from cations of metals and electrons bonded to the ammonia also free electrons are present at higher concentrations of solutions, whereby the conductance is considerably increased. 

The mechanism of oxidation of copper to produce cuprous oxide may be visualized as shown in Figure 1.38. Cuprous oxide is a p-type material and in Figure 1.38(a), the diffusion of cuprous ions to the metal to air/oxide through cation vacancies is shown with the path indicated by arrows. The oxygen molecules react with cuprous ions at the... 

In the binuclear haem-copper centre of cytochrome oxidases there is no cation radical formed at the active site. Instead the extra positive charge is held by the copper atom as it converts from cuprous (Cu1+) to cupric (Cu2+). In fact there is growing evidence to support the model of Mitchell [56] that it is the protonation steps associated with oxidation state changes in this copper atom (Cub) that provide the link between the electron transfer and proton translocation activities of this enzyme. 

The static dielectric constant (eo) of the alkali azides (cf. Table 11) is of the order of 6.5 while is 2.3. These values are of the same order as those of the alkali halides. Both the high and low frequency dielectric constants increase in the case of thallous. silver and cuprous azides. This is likely to be due to the increasing polarizibihty of the cations and a reflection of the decreasing ionicity of the lattices. The eo value for thallous azide and silver fulminate are however surprisingly high compared with the other azides. 

Copper occurs in soil solids and solutions almost exclusively as the divalent cation Cu ". However, reduction of Cu " (cupric) to Cu (cuprous) and Cu (metallic copper) is possible under reducing conditions, especially if halide or sulfide ions ( soft bases) are present to stabilize Cu" (a soft acid). Copper is classified as a chalcophile, owing to its tendency to associate with sulfide in the very insoluble minerals, CU2S and CuS. In reduced soils, then, copper has very low mobility. Most of the colloidal material of soils (oxides of Mn, Al, and Fe, silicate clays, and humus) adsorb strongly, and increasingly so as the pH is raised. For soils with high Cu accumula-... 

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