Enthalpies of solution of glycylglycine in water–organic solvent media at 298.15 K

The enthalpies of solution of glycylglycine in aqueous solution of 1,4-dioxane, acetone, formamide, N-methylformamide and N,N-dimethylformamide, with the co-solvent content up to 0.4 mole fractions, have been measured calorimetrically at T = 298.15 K. The results obtained were used to calculate the standard enthalpies of solution (ΔsolH°) and transfer (ΔtrH°) of the glycylglycine from water into the mixtures as well as the enthalpy coefficients of pair-wise interaction hxy of the solute with the organic co-solvents in aqueous media. The hxy values were correlated with the properties of organic solvents using the Kamlet–Taft equation. The effect of the structure properties of the mixed solvent on the specified enthalpy characteristics of glycylglycine is discussed.