Electron spin resonance studies of copper(II) in haemocyanin, its chelates with (±)-mercaptosuccinic acid, and some related systems

Abstract

E.s.r. measurements have been made on haemocyanin sampfes derived from the South Australian crayfish, Jaws lalandii. In order to assist in the interpretation of the results the e.s.r. spectra given by copper(ii) in a number of different states of combination have been studied, e.g.. copper( 11) complexes of the following : insulin, the oxygenated condensation product of copper( 11) oxalodihydrazide with acetaldehyde or acetone, copper( I) chloride in acetonitrile or hydrochloric acid, and mercaptosuccinic acid in aqueous and non-aqueous solutions. From a consideration of the spectra obtained in these model systems some of the difficulties involved in the interpretation of the haemocyanin results are resolved.

Mixed metal zinc (II)-molybdenum (VI) peroxo complexes containing some amino acids and acetic acid

“…The coordination of amino acid and acetic acid ligands is indicated by the shift in the stretching vibrations v (COO-) and v (NH/NH2) compared to free amino acid/acetic acid (Sastry et al 1994a). The chemical analysis of peroxo oxygen atoms, and valency considerations also suggests that amino acids function as deprotonated univalent anions and the observed IR bands are in accordance with those reported for the corresponding glycylglycinates (Boas et al 1969), glycinates (Tomita 1961;Butcher et a11976) and acetates (Ei-ichiro Ochia 1973). The coordination of water molecule is identified by v(H20) bands at 3390, 3460 and 3400 cm -~ for 1-3 respectively.…”

Electron spin resonance study of the structure of certain polynuclear copper(II) polyaminocarboxylate chelates and the dimeric copper chelates of N,N'-diglycylethylenediamine

“…The computer programs used to obtain these results were the same as those used in the previous studies. [10][11][12][13][14][15] By variation of the magnetic parameters used in the simulation of the spectra, a unique set was obtained for each experimental spectrum. Thus the main spectral features of the experimental result were fitted within ±5 G. The range of values of each magnetic parameter used to achieve the fitting of the experimental curves to within these tolerances is outlined in Table I.…”

High Spin Systems

“…These methods were extended by Sandy and Gareth Eaton from the late 1970's and around 1979 or 1980 I made available to them all of our dimer simulation programs which they later modified for their work on copper dimers and metal-nitroxyl interacting pairs (9,10) 3 . An important application of these methods to biology concerned the copper protein, haemocyanin (20), a system we had looked at unsuccessfully some time before (21). The hemocyanins are proteins which contain about 130 copper atoms/molecule and for which pair spectra are observed following treatment with NO.…”