The electron spin resonance spectra of β-diamminecopper(II) halides diluted in ammonium halides; bonding parameters

Abstract

Samples of copper(II) diammines doped into ammonium halides and diamminemercury(II) halides exhibit powder e.s.r. spectra characteristic of tetragonally compressed CuX₄L₂ chromophores (X = Cl or Br; L = NH₃, H₂O, and NH₄⁺ or a vacancy). Expressions, which take σ-covalency into account, are derived for the spin-Hamiltonian parameters and used to determine bonding parameters. These show that the axial bonding is stronger in the diluted diammines than in samples grown from neutral solution in the presence of pectin. The electronic reflectance spectra, the identity of the axial species, and the effect of temperature on the bonding parameters are discussed.