Transition metal copper

Norman, M.R. (1984) Application ofa screened self-interaction correction to transition metals copper and zinc, Phys. Rev., B29, 2956-2962. 

As with other first-row transition metals, copper complexes are not expected to be satisfactory singlet oxygen photogenerators, because of the rapid deactivation of excited states in the presence of partially filled d-orbitals. The exceptional case of the copper(II) benzochlorin iminium salt ((18), M = Cu) has already been referred to (Section 9.22.5.6) this showed bioactivity, although the nickel(II) complex ((18), M = Nin) was inactive.195... 

Many aquatic organisms exhibit an ability to concentrate a variety of trace elements and this ability has been identified as a function of the tendency of the elements to be complexed by ligands (159). The alkaline earth metals are poorly com-plexed in relation to the transition metals, copper, nickel, cobalt, zinc and manganese. The actinides should be regarded as members of an intermediate group. It has been suggested by Martin (160) that at least five mechanisms may regulate the uptake of metals by marine biota. These are... 

In addition, a few other publications also address this issue of ballistic modification of composite propellants. The cobalt, nickel and zinc hexammine perchlorates have been studied by Gurdip Singh and coworkers for this purpose. The generated data indicate that cobalt complex accelerates burn rate three-fold when used at 2% level in HTPB-AP-based composite propellant [277]. Another study on transition metals (copper, iron, cobalt and nickel) salts of NTO as BRMs for HTPB-AP-based... 

More recently, chloramine-T (CT) was found to be an efficient nitrogen source for the aziridination of olefins by our group [7a], Among the transition metals, copper(I) chloride was the most suitable catalyst for the aziridination of olefins with CT. For example, frans-P-methylstyrene was successfully aziridinated with CT at 25 °C in acetonitrile in the presence of a catalytic amount of CuCl (Scheme 6). Other olefins have also been aziridinated by the reaction, whose products are shown in Scheme 7. 

Other Transition Metals. Copper. With den, dpn, trien, tetraen, and penten, Cu(II) forms the interesting series (40, 4I) 44)-... 

Sources of transition metals Copper, silver, gold, platinum, and palladium are the only transition metals that are unreactive enough to be found in nature uncombined with other elements. All other transition metals are found in nature combined with nonmetals in minerals such as oxides and sulfides. Recall that minerals are mixed with other materials in ores. Metallurgy is the branch of applied science that studies and designs methods for extracting metals and their compounds from ores. The methods are divided into those that rely on high temperatures to extract the metal, those that use solutions, and those that rely on electricity. Electricity also is used to purify a metal extracted by high temperatures or solutions. 

Distribution of atoms of different nature over the framework positions deserves more discussion. It is noticed that the 16 site of the space group Pm3n is always occupied by atoms of the most electronegative elements— phosphorus or arsenic, whereas the most electropositive elements prefer the 24 site. The latter position is always occupied by various metal atoms, including transition metals copper and zinc and p-metals, such as tin and indium. Another important feature is that vacancies form at the 6c or 24k sites but never at the 16 sites. This pattern is remarkably different from that observed for anionic clathrates. In them, electropositive substituents, including group 13 and some transition metals, either exclusively sit on the 6c site or also occupy the 24 site but always avoid the... 

In dealing with such a vast domain some decisions concerning the subjects addressed in this short chapter had to be made. Consequently, only selected enzymes containing the transition metals copper, iron, manganese, molybdenum/ tungsten, nickel and the related zinc, will be discussed also, we will consider only X-ray structures of active sites published relatively recently and for which some discussion on the catalytic mechanism is included. Some reference is also made to Co in the context of the correnoid iron sulfur protein that interacts with acetyl Coenzyme A synthase in the synthesis or cleavage of acetyl CoA. With a few exceptions, the protein structure beyond the metal coordination sphere will not be described unless it impinges in the catalytic mechanism. 

Evidence in favor of oxidative stress in diabetes has become extensive. For instance, an increase in plasma markers of lipid oxidation occurs in diabetic microangiopathy (Sato et al, 1974 Nishigaki et al, 1981) and the transition metals copper and iron increase in plasma concentration with diabetes (Mateo et al, 1978 Noto et al, 1983 Cutler, 1989), the latter suggesting a decreased ability to sequester these trace elements. Although regulated by acute phase proteins such as ceruloplasmin and ferritin, an increase in either of these metals may imply an increase in the nonsequestered forms able to undergo redox reactions. 

Chitin forms complexes with most transition metals. Copper ions form one of the strongest complexes. The rates of formation... 

ABSTRACT. Knots and interlaced designs have been part of human artistry and culture since the earliest times. In chemistry, knots have been the focus of theoretical investigations for several decades. In pandlel, a few experimental approaches have been attempted by synthetic chemists. Until recent years, the only preparative routes pursued used the tools of classical organic chemistry. Despite their intellectual elegance, they have not succeeded. By taking advantage of the three-dimensional template effect of a transition metal (copper I), it has recently been possible to interlace two molecular threads prior to cyclisation and formation of a dimetallic trefoil knot. The demetallated knotted molecule and its di-copper(I) precursor have been fully characterized and studied. The X-ray structure of the dimetallic trefoil knot has been solved. It confirms the topology of the system. 

Goodfellow RJ (1987) Post-transition metals, copper to mercury. In Mason J (ed) Multinuclear NMR, pp 563-589. New York Plenum. 

Oxidative addition. In an oxidative addition reaction, the oxidation state of the transition metal, copper(I) in a Gilman reagent, changes to copper(III). 

Enamines as Lewis bases are able to coordinate to an unsaturated transition metal which prevents the transition metal from catalyzing diazo decomposition. Among transition metals, copper has relatively low activity and can coexist with the enamine... 

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