Cu compounds

However, in this oxidation state it is copper which provides by far the most familiar and extensive chemistiy. 8imple salts are formed with most anions, except CN and Iwhich instead form covalent Cu compounds which are insoluble in water. The salts are predominantly water-soluble, the blue colour of their solutions... 

C20-0102. Blue copper proteins are blue when they contain Cu but colorless as Cu compounds. The color comes from an interaction in which a photon causes an electron to transfer from a sulfur lone pair on a cysteine iigand to the copper center. Why does this charge transfer interaction occur for Cu but not Cu+ ... 

Review of the isotope geochemistry of the transition metals is continued by Albarede (2004) in Chapter 11, where isotopic variations in Cu and Zn are discussed. The significant changes in bonding environments of Cu(I) and Cu(II) produce significant differences in 5 Cu values for oxidized and reduced Cu compounds, and isotopic variations of up to 9%o are observed in nature. Isotopic variations of Zn are significantly more restricted, where 5 Zn values vary by less than 2%o, but systematic variations are recorded in Fe-Mn nodules from the ocean floor. Measurable isotopic variations are found for Cu and Zn in sedimentary rocks, as well as ore deposits, and this remains a promising aspect of future Cu and Zn isotope studies. 

Accordingly, the total petroleum hydrocarbons at a gasoline spill site will be comprised of mostly Cs to Cu compounds, while total petroleum hydrocarbons at an older site where the fuel has weathered will likely measure mostly Cg to Cn compounds. Because of this inherent variability in the method and the analyte, it is currently not possible to directly relate potential enviromnental or health risks with concentrations of total petroleum hydrocarbons. The relative mobility or toxicity of contaminants represented by total petroleum hydrocarbons analyses at one site may be completely different from that of another site (e.g., Ce to Cn compared to Cio to C25). There is no easy way to determine if total petroleum hydrocarbons from the former site will represent the same level of risk as an equal measure of the total petroleum hydrocarbons from the latter. For these reasons it is clear that the total petroleum hydrocarbons value offers limited benefits as an indicator measure for cleanup criteria. Its current widespread use as a soil cleanup criterion is a function of a lack of understanding of its proper application and... 

Four new dinuclear complexes with subnormal magnetic moments have been synthesized by the reaction of Cu(apxd)2 [apxd = iViV -bis-(3-amino-propyl)oximidate] with another Cu compound such as [(bipy)Cu(N03)2] or [(bipy)2Cu(N03)2]. The complex [Cu2(apxd)(bipy)2]N03 has both metal atoms in five-co-ordinate environments (200). ... 

The carbon content of MSW cannot be converted into C02 entirely, and due to incomplete combustion, minor amounts of CO and soot particles are found in the flue gases. The particulate carbon is known to be involved in the formation of volatile and toxic compounds especially poly-chlorodibenzo-dioxins and -furanes. Tests in the fully working incinerator plants revealed the presence of particulate carbon, chlorides, and Cu compounds as catalysts in the fly ash (see also Table 3). 

La2Cu04 has a structure and crystal chemistry virtually identical to that of La2Ni04 with a couple of important exceptions. Firstly, all octahedrally coordinated Cu compounds show a spontaneous electronic distortion (the Jahn-Teller distortion described in Section 8.3.1) by which the two axial bonds become longer and the four equatorial bonds become shorter. The distortion observed in La2Cu04 is usually attributed to this effect, but the observation of the same distortion in La2Ni04 shows that the driving force in both compounds... 

Although there is an analogy in many aspects between the structural chemistry of heterometallic Au-Ag and Au-Cu compounds, the interest shown in recent years has resulted in a considerable increase in the structural diversity for the gold-silver species resulting from the different strategies used to obtain compounds with a pre-established design, but also due to many unexpected compounds. 

Alkylcopper compounds, R—Cu, also are selective reagents that react with acid chlorides to give ketones, but do not add to esters, acids, aldehydes, or ketones. The R—Cu compounds can be prepared from Cul and the alkyl-lithium. With an excess of the alkyllithium, the alkylcopper is converted to R2CuLi ... 

Figure 17 Structure of the dimeric Cu" compound formed by oxidation of a Cu1 species in a pyridine ligand. The phenolic...

A hexameric Cu compound, in which each Cu atom is coordinated through the non-esterified sulfur and the nitrogen atom, was prepared from the ester of monophenyl dithiocarbamate after deprotonation of the nitrogen atom.54... 

Cu compounds in solution are usually active catalysts for oxidation reactions because of the favorable redox potential of the Cu(II)/Cu(I) couple. 

Fig. 16.30. Pd(0)-catalyzed arytation of a copper acetytide at the beginning of a three-step synthesis of an ethynyt aromatic compound. Mechanistic details of the C,C coupling Step 1 formation of a complex between the catalytically active Pd(0) complex and the arylating agent. Step 2 oxidative addition of the arylating agent and formation of a Pd(II) complex with a cr-bonded aryl moiety. Step 3 formation of a Cu-acetylide. Step 4 trans-metalation the alkynyl-Pd compound is formed from the alkynyl-Cu compound via ligand exchange. Step 5 reductive elimination to form the -complex of the arylated alkyne. Step 6 decomposition of the complex into the coupling product and the unsaturated Pd(0) species, which reenters the catalytic cycle anew with step 1.

In the a compounds with M = Co, Au, Cu [44], the bismaleonitriledi-thiolate chains are nonmagnetic and the susceptibilities are Pauli-like with enhancement [expression (15)] above the Peierls transitions, occurring at M-I Figure 5 shows the temperature dependence of the susceptibility for these compounds. It should be mentioned that the Co analog has a higher susceptibility at high temperatures since the bandwidth is W = 0.5 eV, and therefore smaller than the bandwidths of the Au and Cu compounds, which are W = 0.6 eV. 

For the spherically symmetric Cu d" ion, the common geometries are two-coordinate linear, three-coordinate trigonal planar, and four-coordinate tetrahedral. Some distortions from these ideal geometries are observed, particularly with chelating ligands a fairly small number of pentacoordinate Cu complexes have been isolated and characterized as well. Cu compounds are diamagnetic and colorless, except where the color results from charge-transfer bands or a counterion. Cu complexes are often fairly readily oxidized to Cu compounds the electron-transfer kinetics of several systems have been studied. ... 

The few reported Cu compounds all contain the two most electronegative elements as ligands. The most completely characterized Cu complex is probably the paramagnetic, presumably octahedral complex [CuFe]. Some Cu centers are believed to be present in BaCu02.63, which... 

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