The single-crystal electronic and e.s.r. spectra and magnetic susceptibility of monoethylenediaminecopper(II) dichloride

Abstract

The single-crystal polarised electronic spectra, e.s.r. spectra, and magnetic anisotropy of monoethylenediaminecopper(II) dichloride have been measured. These properties suggest that the principal electronic axis coincides with the axis of a distorted tetragonal environment rather than with the axis of the approximate C₂ ligand-field symmetry. The electronic spectra have been observed in the [100], [001], and [010] faces and assigned in D₂ symmetry with a ²A type ground-state. The sequence of one-electron energy levels has been determined as d_x²–y² > d_xy > d_z²∼d_xz∼d_yz. Expressions are derived for the g-values of the copper(II) ion in crystal fields of D₂ and C₂ symmetry. From the e.s.r. and electronic spectra the combined orbital reduction parameters k_⊥ and k_∥ have been determined as 0·672 and 0·684 respectively.