Effect of adduct formation and self-association on electron spin resonance spectra and electronic structure of copper(II) diethyldithiocarbamate and di-isoprophyl dithiophosphate

Abstract

The solid-state e.s.r. spectra of copper(II) diethyldithiocarbamate and di-isopropyl dithiophosphate dissolved in co-ordinating and non-co-ordinating solvents are compared with single-crystal and powdered samples diluted with the corresponding complexes of Ni^II and Z_n^II. The e.s.r. spectra of [Cu(S₂CNEt₂)₂] and [Cu{S₂P(OPrⁱ)₂}₂] dissolved in non-co-ordinating solvents are similar to those obtained from solid samples where weak self-association is present. E.s.r. spectra of copper(II) adducts are similar to those obtained from self-associated copper(II) complexes in the solid state. On the basis of the present results, it is suggested that in the ground state the unpaired electron is in a hybrid orbital of the d_x²–y², d_z² and 4s atomic orbitals of copper. The coefficients of this molecular orbital show that the effects of adduct formation or self-association increase the contribution of the d_z² and 4s orbitals to the ground state.