Copper complexing and

Copper. Some 15 copper compounds (qv) have been used as micronutrient fertilizers. These include copper sulfates, oxides, chlorides, and cupric ammonium phosphate [15928-74-2] and several copper complexes and chelates. Recommended rates of Cu appHcation range from a low of 0.2 to as much as 14 kg/hm. Both soil and foHar appHcations are used. 

Hydantoin itself can be detected ia small concentrations ia the presence of other NH-containing compounds by paper chromatography followed by detection with a mercury acetate—diphenylcarba2one spray reagent. A variety of analytical reactions has been developed for 5,5-disubstituted hydantoias, due to their medicinal iaterest. These reactions are best exemplified by reference to the assays used for 5,5-diphenylhydantoiQ (73—78), most of which are based on their cycHc ureide stmcture. Identity tests iaclude the foUowiag (/) the Zwikker reaction, consisting of the formation of a colored complex on treatment with cobalt(II) salts ia the presence of an amine (2) formation of colored copper complexes and (3) precipitation on addition of silver(I) species, due to formation of iasoluble salts at N. ... 

Direct Blue 218 had reported sales of 623 t valued at 4.4 million ia 1987. It is produced from Direct Blue 15 (76) by metallizing and elimination of methyl groups from the methoxide to form the copper complex. Direct Blue 15 (76) is prepared by coupling o-dianisidine [119-90-4] to two moles of H-acid (4-amiQO-5-hydroxy-2,7-naphthalenedisulfonic acid) under alkaline pH conditions. Other important direct blues iaclude Direct Blue 80 (74), (9-dianisidine coupled to two moles of R-acid (3-hydroxy-2,7-naphthalenedisulfonic acid [148-75-4]) followed by metallizing to form a bis copper complex, and Direct Blue 22 (77), an asymmetrical disazo dye, prepared by coupling o-dianisidine to Chicago acid [82-47-3] and 2-naphthol. Direct Blue 75 (78) is an example of a trisazo dye represented as metanilic acid — 1,6-Q.eve s acid — 1,6-Q.eve s acid — (alb) Ai-phenyl J-acid. 

Le Bihan and Courtot-Coupez [202] used the copper complex and flameless atomic absorption spectroscopy to determine anionic detergents. Crisp [200]... 

Several copper enzymes will be discussed in detail in subsequent sections of this chapter. Information about major classes of copper enzymes, most of which will not be discussed, is collected in Table 5.1 as adapted from Chapter 14 of reference 49. Table 1 of reference 4 describes additional copper proteins such as the blue copper electron transfer proteins stellacyanin, amicyanin, auracyanin, rusticyanin, and so on. Nitrite reductase contains both normal and blue copper enzymes and facilitates the important biological reaction NO) — NO. Solomon s Chemical Reviews article4 contains extensive information on ligand field theory in relation to ground-state electronic properties of copper complexes and the application of... 

The product was identihed by a number of spectroscopic methods. Dioxygen uptake was measured by spectrophotometric titration. MALDI-TOF-MS (matrix-assisted laser desorption/ionization-time of flight-mass spectrometry), an MS method particularly suited to determining molecular masses of biopolymers and synthetic materials with relative masses up to several hundred kilodaltons, determined that the product contained stoichiometric amounts of the heme starting material, the copper complex, and dioxygen in a 1 1 1 ratio. 

Table 6 presents a summary of toxic and classical pollutants detected in three common cleansing solutions ammoniacal sodium bromate, hydrochloric acid without copper complexer, and hydrochloric acid with copper complexer. 

The insolubility of the Cu(I) halide salts, as well as the possibility of /x-halo-bridge formation between two copper atoms (as discussed later) or between the copper complex and the electrode surface, suggests that the presence of hahdes may alter the electrochemical properties observed for copper-containing solutions. 

In only one instance, namely, Borassus flabellifer, has there been any report of decomposition leading to altered D-mannose D-galac-tose ratios caused by purification through the copper complexes, and it seems likely that this was due to fortuitous fractionation.37... 

JV-(2-HYDROXYETHYL)-3,5-DIMETHYLPYRAZOLE, A DINUCLEAR COPPER COMPLEX, AND N-(2-p-TOLUENESULFONYLETHYL)-3,5-DIMETHYLPYRAZOLE... 

A number of copper-containing proteins show spectral features like those of normal copper complexes, and therefore do not appear to contain blue copper centres. Amongst these are galactase oxidase and the amine oxidases. It is noteworthy that it appears unlikely that the copper is involved in the activation of dioxygen. 

Robinson, N. J. Thurman, D. A. (1986). Isolation of a copper complex and its rate of appearance in roots of Mimulus guttatus. Planta 169, 192-7. 

Gnassia-Barelli,M., Romeo, M., Laumond, F. and Pesando, D., 1978. Experimental studies on the relationship between natural copper complexes and their toxicity to phytoplankton. Mar. Biol., 47 15-19. 

The possibility of first converting suitable azo compounds into copper complexes, and subsequently using them as coupling components for the synthesis of azo direct dyes, was also described. 

Jezierski, A., Drozd, J., Jerzykiewicz, M., Chen, Y., and Kaye, K. J. (1998). EPR in the environmental control Copper complexes and free radicals in soil and municipal solid waste compost. Appl. Magn. Reson. 14, 275-282. 

The d-d absorption of the copper complex differs in each step of the catalysis because of the change in the coordination structure of the copper complex and in the oxidation state of copper. The change in the visible spectrum when phenol was added to the solution of the copper catalyst was observed by means of rapid-scanning spectroscopy [68], The absorbance at the d-d transition changes from that change the rate constants for each elementary step have been determined [69], From the comparison of the rate constants, the electron transfer process has been determined to be the rate-determining step in the catalytic cycle. 

Electron transfer from the substrates to 02 proceeds by a redox cycle that consists of copper(II) and copper(I). The high catalytic activity of the copper complex can be explained as follows (1) The redox potential of Cu(I)/Cu(II) fits the redox reaction. (2) The high affinity of Cu(I) to 02 results in rapid reoxidation of the catalyst. (3) Monomers can coordinate to, and dissociate from, the copper complex, and inner-sphere electron transfer proceeds in the intermediate complex. (4) The complex remains stable in the reaction system. It may be possible to investigate other catalysts whose redox potentials can be controlled by the selection of ligands and metal species to conform with these requisites several other suitable catalysts for oxidative polymerization of phenols, such as manganese and iron complexes, are candidates on the basis of their redox potentials. 

Figures 10.2 and 10.3 illustrate the electrochemistry for several copper(II) and copper complexes in MeCN. The redox potentials for these copper complexes and their ligands are summarized in Table 10.5 (related data for aqueous media are given in Table 10.6).3,8-13 In addition, the shift in redox potential (AE) for the free ligand (L) and when bonded in a complex (CuL ) is tabulated. This quantity is a measure of the apparent copper-ligand covalent-bond-formation free energy (—AGBF) ...

TABLE 10.5 Redox Potentials for Copper Complexes and Their Ligands in MeCN... 

Dissociation curves for iron ovotransferrin and conditions and calculations related to these curves, are presented in Fig. 7 and Table 10. A similar family of curves and data also were made for the copper complexes and these showed similar relationships when the solutions were more alkaline by approximately 1 pH unit. 

Sykora J. Photochemistry of copper complexes and their environmental aspects. Coord Chem Rev 1997 159 95-108. 

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