Thermodynamic parameters of the dissociation of some azo-beta-diketones in dioxane-water mixtures

ABSTRACT

The dissociation constants of some azo-beta-diketone compounds were evaluated potentiometrically in different dioxane-water mixtures and at different temperatures. The solvent effect has been discussed. The thermodynamic parameters [delta H, delta C and delta S] were evaluated and the isoequilibrium relationship has been tested. A trial was made to calculate the number of water and solvent molecules around the ligands upon dissociation. It was found that the ligand species are more solvated than aquated in the studied mixtures