Solubilities and Gibbs transfer energies of thiolato, sulfenato, sulfinato and tris(ethylenediamine)cobalt(III) complexes, as well as of perchlorate,from acetonitrile into its mixtures with water

Information on the solvation of thiolato complex cations [Co(en)^sub 2^(SCH^sub 2^COO)]^sup +^ [Co(en)^sub 2^(SCH^sub 2^CH(COO)NH^sub 2^)]^sup +^, [Co(en)^sub 2^(SCH^sub 2^CH^sub 2^NH^sub 2^)]^sup 2+^, sulfenato complexes [Co(en)^sub 2^(SOCH^sub 2^COO)]^sup +^ [Co(en)^sub 2^{SOCH^sub 2^CH(COO)NH^sub 2^}]^sup +^, [Co(en)^sub 2^(SOCH^sub 2^CH^sub 2^NH^sub 2^)]^sup 2+^, the sulfinato [Co(en)^sub 2^{SO^sub 2^CH^sub 2^CH(COO)NH^sub 2^}]^sup +^, [Co(en)^sub 2^(SO^sub 2^CH^sub 2^CH^sub 2^NH^sub 2^)]^sup 2+^ as well as of [Co(en)^sub 3^]^sup 3+^ has been obtained from solubility measurements in MeCN-H^sub 2^O mixtures at 298.2 K. The single-ion Gibbs energies of transfer of the Co^sup III^ complexes were derived from the solubilities of picrate and perchlorate salts for the full range of MeCN-H^sub 2^O mixtures. Single-ion Gibbs energies of transfer for the perchlorate ion are given. The effects of the solvent mixtures were interpreted in the framework of chemical bond formation between the ions and the individual solvent molecules.[PUBLICATION ABSTRACT]