Solvation of Cobalt Tetrasulfophthalocyanine in Water-Acetonitrile Solvents

The method of distribution between two immiscible phases is used to determine Gibbs free energies of transfer of cobalt tetrasulfophthalocyanine from water to water-acetonitrile mixtures (Delta(tr)G(0)(CoTSPc)(aq ->chi AN); chi(AN) = 0.0-0.5 mole fractions) at 25 degrees C. The effect of the mixed solvent composition and properties on change in the solvation state of CoTSPc was analyzed. It is found that increasing the content of the organic component in the mixed solvent results in desolvation of the phthalocyanine metal complex. Changes in the solvation state of CoTSPc are associated with a weakening of the solvation of the aromatic system due to a reduction in the energy of the universal solute-solvent type of interaction. Contributions from the resolvation of electron-donor and electron-acceptor centers of the macroheterocycle to Delta(tr)G(0)(CoTSPc)(aq ->chi AN) practically compensate each other.