DOUBLE SALTS OBTAINED FROM ME(-CUX(2)-H2O SYSTEMS (ME(+)=K+, NH4+, RB+, CS+, X(-)=CL-, BR-)()X)

The solubility diagrams of the Me(+)Br-CuBr2-H2O (Me(+) = K+ NH4+, Rb, Cs+) systems are studied. The results obtained are compared with lit erature data on the corresponding chloride systems in order to estimat e the effect of the halide ion (Br- or Cl-) on the solubility diagrams and on the compositions of the double salts formed in these systems. The differences in composition and structure of the double salts are e xplained by the metal-ligand interactions on the basis of Pearson's co ncept of hard and soft Lewis acids and bases, as well as by crystal ch emistry considerations for the most probable spacial situation of the building elements in the crystal structure. (C) 1995 Academic Press, I nc.