Electron spin resonance studies of copper(II) in haemocyanin, its chelates with (±)-mercaptosuccinic acid, and some related systems
E.s.r. measurements have been made on haemocyanin samples derived from the South Australian crayfish, Jasus 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(II) complexes of the following: insulin, the oxygenated condensation product of copper(II) 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.