Electron spin resonance studies of dimer formation by chelates of copper(II) with some amino-acids

Abstract

An e.s.r. spectral study of the dimeric species formed by the copper(II) chelates of NN-bis-(2-hydroxyethyl)glycine, 2-hydroxy-N-(2-hydroxyethyl)ethylamine, and L-thyroxine has been made. The low-field, ΔM= 2 signals observed for these systems have been interpreted in terms of dipole–dipole coupling of the copper(II) ions which arises from dimer formation. Structures for the copper(II) dimers have been proposed which are compatible with the Cu^II–Cu^II separation estimated by a computer simulation of the line shapes.