Enthalpies of solution of glycylglycine and diglycylglycine in aqueous alcohols at 298.15 K

The integral enthalpies of solution of glycylglycine and diglycylglycine in water–ethanol, water–n-propanol and water–i-propanol mixtures were measured at 298.15 K and alcohol mole fraction concentrations (x2) ranging up to 0.3 by calorimetry. The ΔsolH° and ΔtrH° vs. x2 were found to have extrema. Enthalpic coefficients of pairwise interactions (hxy) between peptide and alcohol molecules were positive and increased in the series ethanol, n-propanol, i-propanol.