Interpretation of electron spin-echo modulation for copper(II) complexes in crystalline powders

Abstract

A strategy is outlined for the interpretation of electron spin-echo modulation (ESEM) for copper(II) complexes in crystalline powders. A rigorous treatment is presented for the echo intensity for signals exhibiting large g-anisotropy. This leads to many variables which influence the observed ESEM patterns, making analysis of the data difficult. Two approaches are presented to tackle this problem. (1) One can choose a system for which many of the variables are already known through complimentary techniques such as X-ray crystallography. (2) In some instances for deuterium modulation from deuterated organic ligands or D₂O the nature of the complex allows the use of a spherical-averaging approximation. This approximation ignores g anisotropy and assumes all interacting nuclei to be equivalent, thus simplifying the problem greatly.