
%0 Journal Article
%A Shirvington, PJ 
%T The hydrolysis of some acidic metal cations in acetonitrile containing traces of  water
%J Australian Journal of Chemistry
%D 1967/03/01
%V 20
%N 3
%P 447-457
%K 
%R https://doi.org/10.1071/CH9670447
%U https://www.publish.csiro.au/paper/CH9670447 
%X Acetonitrile is a solvent in which the halogen acids are highly associated. The strongly polarizing Al3+ and Ti4+ ions, when present in acetonitrile with comparable concentrations of water, form very stable hydroxy complexes. These two factors bring about the formation of halogen acids when the metal ions are dissolved in solvent containing halide ions. The results show (at least for aluminium) that it is the dissociation of water rather than of solvent molecules which is involved.   Values obtained by polarography for the degrees of hydrolysis of Al3+ and Ti4+ in 25mM H2O and 0.1M tetrapropylammonium chloride were 0.82 and 0.18 respectively. In 0.1M perchlorate media the values for AlCl3 and TiCl4 were 0.45 and 0.40 respectively, indicating that the hydrolysis of Ti4+ is limited as a result of complexing by competing chloride ions.   Potentiometric titrations, conductance measurements, and u.v. spectra (for TiCl4) support the polarographic results. No significant hydrolysis could be detected for Mg2+, So3+, Ga3+, and Sn4+ in halide solutions of acetonitrile. 
