
TY  - JOUR
A1  - Clare, BW 
A1  - Hefter, G 
A1  - Singh, P 
T1  - Zinc(II)-Chloride Complexes in Acetonitrile-Water Mixtures
JF  - Australian Journal of Chemistry
JO  - Aust. J. Chem.
Y1  - 1990
VL  - 43
IS  - 2
SP  - 257
EP  - 261
KW  - 
UR  - https://doi.org/10.1071/CH9900257 
N2  - Equilibrium constants for the formation of ZnCln2-n complexes have been measured in some acetonitrile ( MeCN )-water mixtures ranging from 0 to 100% MeCN at 25&#176;C and I = 0.1 M (Et4NClO4), by potentiometric titration. The equilibria shift strongly in favour of the formation of the higher-order complexes (n = 3, 4) at high MeCN concentrations. This is shown to be due to differences in the magnitude of unfavourable solvation of the Zn2+, Cl - and ZnCln2-n ions in MeCN-H2O solutions. The Gibbs free energies of transfer of all of these ions from water to MeCN-H2O mixtures are strongly positive, but the net change in the transfer function for the formation of the higher-order complexes is favourable. Thus the formation of these complexes is predominant in MeCN -rich aqueous solutions. Approximate measurements in propiononitrile indicate that the ZnCln2-n complexes are even stronger than in acetonitrile. 
ER  -

