Copper, trivalent

The valency of the complex radicle is the same as that of the central metallic atom when the complex contains only ammonia, substituted ammonia, water, or other neutral group. For example, cobalt in eobaltie. salts is trivalent, and the cobalt complex with ammonia, Co(NI13)8 ", is likewise trivalent copper in cupric sulphate is divalent, and the copper complex, [Cu(NH3)4] , is also divalent. In the same wn.y [Co(NH3)5.H30] " and [Co(NII3)4.(II20)2] " are trivalent, as also [Co(NH3)2.en2]" and [Co.en3] ", where en represents cthyleucdiamine, CH NH2... 

Blumberg, W. E. et at Is trivalent copper a viable oxidation state in the enzymic turnover of copper proteins In Oxidases and Related Redox Systems (King, T. E., Mason, H. S., Morrison, M., eds.), Oxford-New York, Pergamon Press, 1981... 

Meyerstein D (1971) Trivalent Copper. I. A pulse radiolytic study of the chemical properties of the aquo complex. Inorg Chem 10 638-641... 

Hamilton and co-workers (27, 28) have suggested Cu(III) as a probable intermediate in the reaction catalyzed by galactose oxidase. Papers by Kosman and co-workers (29, 30) seem at variance with this interpretation. Regardless of the outcome of this dispute, we hope that our evidence for the existence and properties of Cu(III)—peptide complexes will encourage more investigations of the presence of trivalent copper in biological systems. Our work shows that this oxidation state is readily attained under biological conditions. 

Based on redox potentials and species concentrations, Goldstein et al. (80) suggested an alternative mechanism (reactions (41) and (42)) to explain the unique toxicity of O2 compared to other biological reductants like glutathione and vitamin C. In the alternative system, the copper is oxidized rather than reduced as in reaction (36). The active species in this mechanism is trivalent copper. 

Copper(III) can occur in the solid state and in complexes also in solution. Copper(lII) with a d shell is isoelectronic with nickel(II). Many trivalent copper complexes are short-lived however, copper(III)-peptide complexes have a relatively long lifetime in aqueous solution [2]. 

Copper has g = 11, trivalent copper has z = 3, and for the number of d electrons we have accordingly q = 8. Cu exists other d sterns with two stereochemistries, square planar as typical of Pd°, Pt , and Au and octahedral as typical of Ni°. In square planar [Cu I05(0H) 2] " the ground state may, in accordance with analogous systems, be labeled as... 

The adsorption of trivalent copper cyanide from solution can be neglected when the pH is lower than 8 because it exists in very small amounts. If we assume that all the protonated sites can adsorb copper cyanide species, and the effect of ionic strength can be neglected in the adsorption processes, the modified multicomponent Langmuir isotherm can be written for total amount adsorbed q as follows ... 

D-Galactose Oxidases.—E.s.r. spectroscopic measurements have indicated that trivalent copper is probably an intermediate in reactions catalysed by D-galactose oxidase. ... 

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