CO, and Cu complexes

P-lO - Biomimetic oxygen transfer by Co and Cu complexes immobilized in porous matrices... 

Thomas F, Arora H, Philouze C et al (2010) Co and Cu° complexes of reduced Schiff bases generation of phenoxyl radical species. Inorg Chimica Acta 363 3122-3130... 

The coordinately unsaturated [M(bpy)]+ ions of Co, Ni, and Cu were also reacted with 02. The Co and Ni complexes formed the dioxygen ion but the Cu complex was unreactive. 

It has previously been shown that the oxazines (169) can isomerize by ringopening to the Schiff bases (170). The reactions of the oxazines with Ni , Co", and Cu" have now been examined in the hope of yielding chelates of the Schiff bases. However, the products were not the expected ones in the case of nickel, two kinds of chelate were obtained. Those formed in the absence of air were (171), in which proton migration from the original ligand had occurred, and, in the presence of air, (172) was formed in which dehydration had taken place on the original oxazine. The Co" and Cu" chelates are structurally analogous to the nickel complexes. ... 

Lee, J. and Jonasson, I.R. (1983) Contribution of organic complexation to Ni, Co and Cu speciation in surface waters implications for hydrogeochemical surveys. J. Geochem. Explor, 18, 25-48. 

A series of articles is devoted to the preparation of Pc complexes from metal alloys ([21a] and references cited therein). The most important advantage of the alloys use is an easier reaction between phthalonitrile and the alloy s component(s), due to a concentration gradient of metal particles on the alloy surface. As a consequence of such an interaction, it is possible to obtain polynuclear phthalocyanines and separate the alloy [21a]. This relatively new and intriguing field in Pc research should undoubtedly be taken into account. Another nonstandard technique for metal phthalocyanine production is the use of microwave irradiation under solvent-free conditions (for more details see Sec. 3.5). In particular, this method was used for obtaining phthalocyanine derivatives of Ru, Rh, Pt, and Pt [21b], Zn, Mg, Co, and Cu [21c], or Si [21d]. 

The following Table (Table 1) shows the values of the stability constants of some purines and pyrimidines with a number of transition metal ions (7, 2, 36, 69). Procedures for the synthesis of Cu, Co and Ni complexes with pyrimidines have been reported (65, 92, 93). The preparation of purine-metal compounds are described elsewhere (94, 95). There seem to be great difficulties in the quantitative study of metal complex formation, especially with the free purines, since the resulting metal chelates are almost insoluble in aqueous solution. Therefore, dioxane-water mixtures have been employed in a number of experiments. 

The oxidation is catalyzed by various heavy metal ions such as Cu , Fe (hemin complex), Ni and Co and their complexes,and more importantly, the addition of these ions leads to the selective formation of disulfides without any overoxidized products. The cluster (Bu"4N)2[Fe4S4(SR)4], the analog of the active site of nonheme iron-sulfur proteins, catalyzed extremely smooth oxidation of thiols by oxygen to disulfides in acetonitrile at 0 C (equation 4), while in the case of FeCb or FeCb catalysts oxygen uptake was very slow." The catalysis by AI2O3 for aerobic oxidation is also common. Thus, by stirring thiols in benzene with exposure to air at room temperature for 4-6 h disulfides were obtained almost quantitatively except in the hindered case of Bu SH. 

This section covers some other heterometallic rare earth oxides, including Al, Ti, Zr, Sn, Mo, W, Mn, Fe, Co, Ni, and Cu complex oxides, while certain well-known oxysalts, Y-Ba-Cu-O, for example, will not be specifically discussed. For these heterometallic compounds, due to their relatively complex compositions, it is usually difficult to obtain phase-pure products, especially when some dopant ions are added. At elevated temperatures, some of these oxides undergo phase transitions, which may significantly change their physical and chemical properties such as thermal expansion coefficient and ionic conductivity. And for fhose oxides with variable metal valencies, different nonstoichiometric compositions may also result in distinct functionalities in magnetism and catalysis. 

The anti conformation preferred by the adenine residue in 5 -AMP (Figure lb) disposes this nucleotide to simultaneous inner-sphere binding of metal ions both to the phosphate oxygen and N-7 atoms. As would be expected, neither 2 -nor 3 -AMP (Figure Ic) is able to participate in forming the same type of complex for steric reasons. As was shown in experiments involving Mg +, Mn +, Cd +, Co +, and Cu +,... 

Condensation of an acrylic acid-cellulose graft copolymer with 5-amino-l,10-phe-nanthroline (233) has been utilized to provide polymer (234 Scheme 113) with the phenanthroline ligand oriented optimally for complexation 77MI11110). The polymer was described as exhibiting a strong sorption capacity for Co and Cu "" ions. 

Direct initiation by either mechanism is characterized by a lack of induction period (47) and is most efficient by metals that are strongly oxidizing (Co and Fe) or can form metal-oxygen complexes (Co and Cu). 

A recent elegant example of the tailoring the chemical properties of encapsulated metal complexes is the work of Balkus etal. who prepared and studied perfluorinated phthalocyanine complexes of Fe, Co, Cu and Ru (Scheme 25)[230] in NaX. Perfluorinating the complexes enhances the stability and catalytic activity of the catalysts in the oxyfiinctionalisation of light alkanes. The rapid deactivation of the catalysts based on Fe, Co and Cu Fj Pc complexes was overcome by using Ru as the metal center. Similar catalysts, i.e.,Co-phthalocyanine (Co-Pc) encapsulated in zeolite Y, are active catalysts for cyclohexene and 1-hexene epoxidation (Scheme 27)[231]. Comparison of the activity of free and encapsulated Co-Pc has shown that the interaction with the zeolite stabilizes the complex. Co-Pc is still active after 24 hrs reaction whereas the free complex in solution is virtually inactive after 15 minutes. 

Metal ion binding to (133) is quite strong and saturation kinetics occur at low metal ion concentrations presumably leading to complexes of type (134). Base hydrolysis of the Cu" complex is observed, but attack by both H2O and OH occurs with the Ni", Co" and Zn" complexes. Rate enhancements of > 10 occur for water attack. 

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