Issue 3, 1981

Electron spin resonance study of copper(II)–amino-acid complexes: evidence for cis and trans isomers and the structures of copper(II)–histidinate complexes in aqueous solution

Abstract

Electron spin resonance spectra are reported for copper(II)–amino-acid complexes [CuL]n+ and [CuL2]m+(for 12 α-amino-acids) and [Cu(HL)L]+(HL = L-histidine). Buffer solutions of aqueous copper(II) and ligand were prepared to give optimum concentrations of these complexes. Isotropic g and A values are in the ranges 2.144–2.157 and 5.5–6.5 mT respectively for [CuL]n+ and 2.118–2.127 and 6.4–7.1 mT respectively for [CuL2]m+. The high-field absorption for [CuL2]m+ complexes showed nitrogen hyperfine structure, which for 63Cu and solvent D2O could be resolved in the second derivative into two overlapping quintet components characteristic of cis(N, N, O, O) and trans(N, O, N, O) isomers respectively. Spectra have been fitted to this model by computer simulation. From observed nitrogen hyperfine structure, and by comparison with spectra of other amino-acid complexes and that of bis(histamine)copper(II), it is deduced that the histidinate complex [Cu(HL)L]+ has three nitrogen atoms co-ordinated to copper in the planar co-ordination sites, whereas [CuL2] appears to consist of a mixture of structures having three and four nitrogen atoms bound to the copper.

Article information

Article type
Paper

J. Chem. Soc., Dalton Trans., 1981, 822-827

Electron spin resonance study of copper(II)–amino-acid complexes: evidence for cis and trans isomers and the structures of copper(II)–histidinate complexes in aqueous solution

B. A. Goodman, D. B. McPhail and H. K. J. Powell, J. Chem. Soc., Dalton Trans., 1981, 822 DOI: 10.1039/DT9810000822

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Spotlight

Advertisements