X-Ray Diffraction Study of Some Concentrated Cobalt(II) Chloride Solutions

Diffraction results, interpreted in light of colligative measurements, indicate that the environment of Co(II) differs drastically when CoCl2 is dissolved in water and in alcohols. In H2O, the predominant cation species is Co (H2O)62+ with the Co–O distance being about 2.1 Å. In methanol and ethanol, the solute species is highly associated and each Co(II) has four chloride nearest neighbors at about 2.30 Å. The relative co-ordinating abilities of the potential ligands towards Co(II) are H2O > Cl− > CH3OH≃C2H5OH. Crystal radii serve to interpret bond distances.