X-Ray Diffraction and Structural Properties of Aqueous Solutions of Divalent Metal-Chlorides

Abstract

X-ray diffraction data are reported for aqueous solutions of CaCl2 (6.30 M), CdCl2(0.87 and 1.26 M) and NiCl2(1.96 and 3.88 M). The highly concentrated CaCl2solution shows a medium range order resembling that of the corresponding hydrate crystal. The CdCl2solutions are characterized by the presence of complexes with chloride ions in the first coordination sphere of the cation. In NiCl2solutions, a first sphere Ni-Cl coordination can be excluded and the existence of six Ni-H2O nearest neighbour contacts is clearly confirmed. In these solutions no evidence was found for the existence of highly ordered structures; hexa-aquo cations interact with external water molecules and, at the highest concentration, some outer sphere Ni-Cl correlation is possible as due to packing. © 1980, Walter de Gruyter. All rights reserved.