THE SOLUTE AND AQUAION STRUCTURE IN A CONCENTRATED AQUEOUS-SOLUTION OF COPPER(II) CHLORIDE

Neutron diffraction experiments were carried out on isotopically labelled copper chloride (CuCl2) salt in a 4 molal aqueous solution. The first- and second-order isotopic difference methods were used to obtain structural information on the hydration structure of the Cu2+ and Cl- ions and to calculate the pair distribution functions g(CuCl)(r) and g(ClCl)(r) The results confirm the highly distorted nearest-neighbour coordination of Cu2+ and give direct evidence that Cu-Cl contacts exist over a range 2.3 less than or equal to r (Angstrom) less than or equal to 3.5. Analysis of g(ClCl)(r) gives consistent information with that of g(CuCl)(r) and shows that direct contacts also exist between Cl- ions, over the range 2.8 less than or equal to r (Angstrom) less than or equal to 4.2.