Copper salts structure

Tertiary acetylenic halides give unsatisfactory results owing to further isomerization of the allenic halide into a conjugated diene system under the influence of the copper salt. Bromo- and iodoallenes with the structures R R2C=C=CH-X can also be synthesized by an aqueous procedure, consisting of reaction between... 

Iodide ions reduce Cu to Cu , and attempts to prepare copper(ll) iodide therefore result in the formation of Cul. (In a quite analogous way attempts to prepare copper(ll) cyanide yield CuCN instead.) In fact it is the electronegative fluorine which fails to form a salt with copper(l), the other 3 halides being white insoluble compounds precipitated from aqueous solutions by the reduction of the Cu halide. By contrast, silver(l) provides (for the only time in this triad) 4 well-characterized halides. All except Agl have the rock-salt structure (p. 242). Increasing covalency from chloride to iodide is reflected in the deepening colour white yellow, as the... 

The above-described structures are the main representatives of the family of nitrogen ligands, which cover a wide spectrum of activity and efficiency for catalytic C - C bond formations. To a lesser extent, amines or imines, associated with copper salts, and metalloporphyrins led to good catalysts for cyclo-propanation. Interestingly, sulfinylimine ligands, with the chirality provided solely by the sulfoxide moieties, have been also used as copper-chelates for the asymmetric Diels-Alder reaction. Amide derivatives (or pyridylamides) also proved their efficiency for the Tsuji-Trost reaction. 

Ruthenium-copper and osmium-copper clusters (21) are of particular interest because the components are immiscible in the bulk (32). Studies of the chemisorption and catalytic properties of the clusters suggested a structure in which the copper was present on the surface of the ruthenium or osmium (23,24). The clusters were dispersed on a silica carrier (21). They were prepared by wetting the silica with an aqueous solution of ruthenium and copper, or osmium and copper, salts. After a drying step, the metal salts on the silica were reduced to form the bimetallic clusters. The reduction was accomplished by heating the material in a stream of hydrogen. 

EPR and proton ENDOR measurements on Cu(II)-doped zinc acetate have been reported by Atherton and Horsewill215). In contrast to the pure copper salt, which consists of copper pairs, zinc acetate has a monomeric structure in which two water molecules are coordinated to each zinc ion216), as illustrated in Fig. 40. The magnetic parameters are summarized in Table 13. Both the g and ACu tensor obtained from single crystal and... 

Although Schardinger did not propose a structure for his crystalline dextrins, he made several observations that can now be attributed to their cyclic structure. For example, he discovered their ability to engage in complex-formation "With various substances, the crystalline dextrins form loose complexes which, like those produced with alcohol, ether, and chloroform, are indeed partly decomposed by water, while the iodine complexes are more stable toward water. He also found, as previously mentioned, that the crystalline dextrins were nonreducing toward copper salts and nonfermentable by yeast. This last observation he considered was "... the most essential thing that I was able to mention concerning the formation of crystalline dextrins by microbes. Both of these observations can be explained by the lack of a chain termination. 

The discovery of high Tq superconductivity in La2-xMxCu04 (M = Ba, Sr) (Bednorz and Muller 1987) based on perovskite and rock-salt structures has led to an international effort in superconductivity research over the last decade. The principles that govern superconducting copper-oxide-based materials have enormous significance in the application of these oxides as potential catalysts... 

Mercuric-5-nitrotetrazole [Structure (2.13)] was prepared according to the methods reported by Gilligan et al. [14] and Redman and Spear [15]. Thus, 5-aminotetrazole was treated with sodium nitrite and copper sulfate to obtain Cu(NT)2HNT-4H20 (where NT nitrotetrazole). The copper salt was subsequently converted to the ethylene diamine complex MNT was then obtained by treating the complex with mercuric nitrate in HN03 medium. The precursors and final product were air dried. The synthesis of these compounds is carried out in a fume hood behind a protective polycarbonate shield in a stainless steel reaction vessel. 

Reaction of the bis(pyridine-2-aldoxime) copper salt with silver ions has been reported to lead to a heterobinuclear species being produced. The perchlorate salt could be isolated from neutral solution and the OH stretch of the intramolecularly H-bonded species of the starting material at 1600 cm-1 was not observed. The most likely structure was given as (17). The dissociation constant for equation (7) was determined as 2.2 0.3 x 10-3 dm3 mol-1.167... 

S02(g) in the extraction of copper, rock-salt structure A crystal structure the same as that of a mineral form of sodium chloride, roentgen equivalent man rem The unit for reporting dose equivalent. See also sievert. root (of an equation) The solutions of the equation f(x) = 0. See also Appendix IE. root mean square speed c The square root of the average value of the squares of the speeds of the molecules in a sample. 

The only example of a monofluoride is that of silver, although such compounds might be expected for copper and gold, in the same triad. Silver fluoride has the simple rock-salt structure, and the most recent... 

The spectrum of the unstable diatomic CuF molecule has been observed at high temperatures, from the vapor above molten copper(II) fluoride (10), but no evidence for the solid material has been obtained, even after rapid quenching to room temperature. Lattice energy calculations, assuming that CuF would have the rock-salt structure, show that the disproportionation... 

Finally, the remarkably simple solution came from Evans et al. [21a] and researchers of DuPont [21b] simultaneously. Their method allows the coupling of structurally and electronically diverse phenols and aryl boronic acids in the presence of copper]11) acetate, trie-thylamine or pyridine, and molecular sieves at ambient temperature (Scheme 5). Even phenolic amino acid derivatives react smoothly without racemization. The only limitation has been observed when using orfho-heteroatom substituted boronic acids which resulted in lower product yields. The initial step in the proposed pathway (Scheme 6) is the trans-metallation of the boronic acid residue with the copper salt. 

Rollier, M. A. and E. Arreghini Structure of Copper Salts of Some Complex Cyanides I. Structure of Copper Salts of the Hexacyanides of Cobalt and Chromium. Gazz. chim. Ital. 69, 499 (1939). 

Methylmercury complexes of allopurinol (56) and l-methylpyrazolo[3,4-from aqueous solutions and characterized <87ICA181>. Copper complexes of allopurinol have also been prepared by reaction with copper salts and their structures were elucidated by x-ray crystal structural analysis <87ZN(B)195>. 

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