Electron spin resonance studies in crystals

Abstract

This thesis embodies the results of the investigations carried out by the author on the electron spin resonance of some of the iron group transition metal ion complexes in order to elucidate the nature of metal-ligand binding. The complexes studied were obtained by one of the following methods: i. Pure complexes isomorphously diluted by the diamagnetic complexes. ii. Producing paramagnetic ions of a transition metal ion in the diamagnetic state by X-ray or ultraviolet irradiation. iii. By introducing transition metal ions in the paramagnetic state in traces in a diamagnetic ferroelectric crystal lattice. Wherever possible, optical absorption studies were also carried out on the substances either in single crystal form or in solution. In the complexes chosen for the present study, the transition metal ions are coordinated to oxygen of the sulfoxide group of diphenyl sulfoxide molecule, oxygen of the carbonyl group of antipyrine molecule and oxygens of oxalate chelate. In all these complexes the metal-ligand binding is found to be highly ionic.