Haloacetate complexes of cobalt(II), nickel(II), and copper(II), and the question of band assignments in the electronic spectra of six-co-ordinate cobalt(II) complexes

Abstract

Complexes of the general formulas M(pyridine)₂(CH_xH_3–xCO₂)₂ where x= 1, 2, or 3 and M = Co^II, Ni^II, and Cu^II and X = F or Cl, have been characterised by vibrational and electronic spectroscopy, magnetism, conductivity, and molecular weight studies. The complexes are six co-ordinate and may be monomeric involving bidentate haloacetate groups, or dimeric according to the solvent and temperature.

The visible absorption band of the cobalt haloacetate complexes shows structure interpreted in terms of tetragonal distortion.