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

The solubility diagrams of the Me(+)Br-CuBr2-H2O (Me(+) = K+ NH4+, Rb+, Cs+) systems are studied. The results obtained are compared with literature data on the corresponding chloride systems in order to estimate 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 explained by the metal-ligand interactions on the basis of Pearson's concept of hard and soft Lewis acids and bases, as well as by crystal chemistry considerations for the most probable spacial situation of the building elements in the crystal structure. (C) 1995 Academic Press, Inc.