Enthalpies and entropies of solution of tris(3-hydroxy-1,2-dimethylpyridin-4-onato)aluminium(III) in methanol–water mixtures from temperature dependences of solubilities

Abstract

Solubilities of tris(3-hydroxy-1,2-dimethylpyridin-4-onato)aluminium(III), AlL₃, have been determined in a series of methanol–water solvent mixtures (0, 20, 40, 60, 80 and 100% methanol) over the temperature range 278.2 to 310.2 K. Solubility maxima are independent of temperature. Enthalpies and entropies of solution exhibit compensation. Maxima in thermodynamic solution parameters do not correspond to maximal solvent structural effects and are therefore assignable to solute–solvent rather than to solvent–solvent interactions.