Second-order effects and hyperfine structure of nitrogen and hydrogen in the EPR spectrum of glycine chelate with 63Cu 2+ in triglycine sulphate

Abstract

The angular dependence of the electron spin resonance of 63Cu 2+ has been measured in triglycine sulphate and the spin-Hamiltonian parameters: g-factor, the hyperfine splitting, A Cu, and the ligand hyperfine splittings, A N and A H, have been found. The angular dependence of spectra is found to obey Bleaney's equation for the energies of the spin states calculated to second order for the magnetic hyperfine interaction. In addition to the hyperfine structure arising from the nitrogen atoms, extra hyperfine lines produced as a result of the interaction of the unpaired electron with hydrogen atoms have been observed. Deuteration of triglycine sulphate by the replacement of the hydrogen atoms of the amine groups by deuterium proved that these protons are the responsible for the observed hydrogen hyperfine interaction.