Copper I Compounds

LEWIS BASE ADDUCTS OF 1,1,1,5,5,5-HEXAFLUORO-2,4-PENTANDIONATO-COPPER(I) COMPOUNDS 

CHECKED BY MALCOLM A. DE LEO,5 SUBHASH C GOEL,5 and WILLIAM E. BUHRO  

In particular, CVD of the derivatives Cu(hfac)(PMe3),1,2 Cu(hfac)(l,5-cod),3-6 Cu(hfac)(2-butyne),7,8 and Cu(hfac)(vtms),9-12 where 1,5-cod = 1,5-cyclooctadiene and vtms = vinyltrimethylsilane, has been studied in detail. These species can be used to deposit copper films either selectively or nonselectively on various surfaces depending on the nature of the precursor, the deposition conditions, and the substrate surface pretreatment. The syntheses of these species from a general salt elimination reaction according to eq. (2) is described here in detail.10,13,15-17 It should be noted that other general methods of preparation of this class of compounds have been reported elsewhere.18 

CuCl + PMe3 + Na(hfac) - Cu(hfac)PMe3 + NaCl 

5-HEX AFLU ORO-2,4-PENT ANDION ATO(2-BUTYN E) COPPER(I), [Cu(hfac) (2-butyne)] 

5-HEXAFLUORO-2,4-PENTANDIONATO-(1,5-CYCLO-OCTADIENE) COPPER(I), [(hfac)Cu(l,5-cod)l 

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In contrast to the + 2 state, copper(I) compounds are less frequently coloured and are diamagnetic, as expected since the 3d level is full. However, the copper(I) ion, unlike copper(II), is unstable in aqueous solution where it disproportionates into copper(II) and copper(O) (i.e. copper metal). 

This copper(I) compound, unlike the above, is soluble in water and therefore in the presence of water liberates copper and forms a copper(II) compound ... 

The main by-products of the Ullmaim condensation are l-aniinoanthraquinone-2-sulfonic acid and l-amino-4-hydroxyanthraquinone-2-sulfonic acid. The choice of copper catalyst affects the selectivity of these by-products. Generally, metal copper powder or copper(I) salt catalyst has a greater reactivity than copper(Il) salts. However, they are likely to yield the reduced product (l-aniinoanthraquinone-2-sulfonic acid). The reaction mechanism has not been estabUshed. It is very difficult to clarify which oxidation state of copper functions as catalyst, since this reaction involves fast redox equiUbria where anthraquinone derivatives and copper compounds are concerned. Some evidence indicates that the catalyst is probably a copper(I) compound (28,29). 

Cupro-. cuprous, copper(I), cupro-. -chlorid, n. cuprous chloride, copper(I) chloride, -cy-aniir, n. cuprous cyanide, copper(I) cyanide cuprocyanide, cyanocuprate(I). -jodid, n. cuprous iodide, copper(I) iodide, -mangan, n. cupromanganese. -oxyd, n. cuprous oxide, copper(I) oxide, -salz, n. cuprous salt, cop-per(I) salt, -suifocyantir, n. cuprous thiocyanate, copper (I) thiocyanate, -verbin-dUDg, /. cuprous compound, copper(I) compound. 

Kupferozydul, n. cuprous oxide, copper(I) oxide, -hydrat, n. cuprous hydroxide, cop-per(I) hydroxide, -salz, n. cuprous salt, copper (I) salt, -verblndung,/. cuprous compound, copper(I) compound. 

Mechanistically, these diazonio replacement reactions occur through radical rather than polar pathways. In the presence of a copper(I) compound, for instance, it s thought that the arenediazonium ion is first converted to an aryl radical plus copper(II), followed by subsequent reaction to give product plus regenerated copper(l) catalyst. 

Suggest a reason why copper(II) compounds are often colored but copper(I) compounds are colorless. Which oxidation number results in paramagnetic compounds ... 

While on the subject of reviews, attention should also be directed to a very recent collection of articles on isocyanide chemistry edited by Ugi 156). This volume is oriented somewhat toward the organic chemistry of isocyanides, but not with the complete exclusion of metal complexes of these species one is directed in particular to the chapters by Vogler (Chapter 10) on coordinated isocyanides and by Saegusa and Ito (Chapter 4) on a-additions to isocyanides. These latter reactions are often catalyzed by copper(I) compounds and occasionally by other metal complexes as well, and it is believed that this catalysis is accomplished by intermediate formation of metal isocyanide complexes. 

As a consequence of its electronic configuration, a variety of coordination numbers and geometries have been observed for copper(I) compounds, especially for inorganic representatives (see Fig. 1.3) [32]. In the organometallic chemistry of copper, the linear and trigonal coordination geometries in particular, though distorted towards T-shaped, are frequently encountered. 

Lippard, S.J., Ucko, D.A. 1968. Transition metal borohydride complexes. II. Th reaction of copper(I) compounds with boron hydride anions. Inorg Chem 7 1051-1058. 

The chemistry of copper(I) is very much less extensive than that of copper(II) and a number of accounts occur5,6,1012 17 20 21 which describe the chemistry of simple compounds of copper(I) with less emphasis on the formation of coordination compounds of copper(I).101317,22 During the past 20 years the realization that a copper(I) species may be involved as the precursor of the silent partner in the type III copper proteins24 25, ZB has. resulted in a renaissance in the coordination chemistry of copper(I) compounds,10,17,30 which is reflected in the amount of space given to the chemistry of copper(I) and (II) in Advanced Inorganic Chemistry by F. A. Cotton and G. Wilkinson. In the first edition in 1952,17a more space was devoted to copper(II)... 

The formation of infinite two-dimensional sheet structures in copper(I) compounds (Figure... 

Results from the same laboratory have appeared on carbon dioxide complexes with copper(I) compounds (124). Phosphine-containing copper(I) car-boxylate complexes, formed by the insertion of C02 into a copper-alkyl bond, take up additional C02. A complex, formulated as [(RC00)Cu(C02)-(PPh3)J has been isolated and the C02 shown to be labile, i.e., the C02 was lost on attempted recrystallization. The authors speculate that the car-... 

Cuprous Compounds. Same as Copper (I) Compounds. See in this Volume, p C 515-R... 

It is worthwhile to analyze why co-existing soft ligands assist low oxidation numbers. If we want to make a copper(I) compound, it is very difficult to try the aqua ion, the fluoride or the anhydrous sulphate because they disproportionate to the metallic element and a higher oxidation state, here Cu(II). However, as seen in Eq. (7) it is easier to make the ammonia complex Cu(NH3)2 under anaerobic conditions, and even easier to make copper(I) complexes of pyridine and of conjugated bidentate ligands such as 2,2 -dipyridyl and 1.10-phenanthroline. The experimental problems are reversed in the case of iodides and cyanides, where it is easy to precipitate Cul or CuCN or to prepare solutions in an excess of the ligand containing Cul J,... 

Biaryls are available through coupling of the aryl halide with an excess of copper at elevated temperatures (200 °C). The active species is a copper(I)-compound which undergoes oxidative addition with the second equivalent of halide, followed by reductive elimination and the formation of the aryl-aryl carbon bond. 

Dooley et al. first proposed an inner-sphere electron transfer mechanism where O2 binds directly to copper(I) 55 this was based upon precedence that suggested very rapid reactions between O2 and synthetic copper(I) compounds used as spectroscopic models for enzyme active sites. A three-coordinate copper(I) geometry in the CAOs had been demonstrated upon reduction with dithionite under anaerobic conditions.56 The reduction of the enzyme anaerobically with primary amine substrates actually produces two states, a copper(I)/semiquinone and a copper (II)/aminoquinol (Figure 9.11). In plant-derived and bacterial CAOs, these states have been demonstrated to exist in rapid equilibrium, due to intraprotein electron... 

These additives also serve to suppress the formation of a common side-product, that is, an allene containing a hydrogen atom instead of the carbon substituent which should have been delivered by the cuprate. The occurrence of such reduction products is also in accordance with the generally accepted mechanistic model (Scheme 44), in which the copper(m) intermediate 186 resulting from the epoxide 185 may be sufficiently stable to survive until work-up of the reaction mixture (or undergo reductive elimination of R-R to give an allenic copper(i) compound), so that protonation leads to the reduction product 188, besides the desired substitution product 187 (Scheme 45).65,74... 

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