Electron spin resonance and relaxation studies of some organic copper salts

Abstract

Detailed electron spin resonance measurements at both X band and Q band are reported for the copper ion in single crystals of maleonitrile dithiolate having as cations the tetra methyl ammonium tetra ethyl ammonium and tetra-n-butyl ammonium groups (referred to as Me2CuMNT, Et2CuMNT and Bu2CuMNT respectively), and for the mixed Cu/Ni salts. X-ray data were also obtained for these and for the Ni salts. The most important features of this study are (i) the alteration in crystal structure caused by the substitution of copper for nickel or cobalt, (ii) the presence of strong copper- copper exchange interaction in spite of the considerable stoichiometric dilution, and (iii) the unusual spectrum observed for Bu2CuMNT. Spin-lattice relaxation measurements were carried out using the pulse- saturation method at 9.27 GHz in the temperature range 1.6-4.2 degrees K on single crystals of the Bu2CuMNT.