Dependence of enthalpies of dissolution of β-alanyl-β-alanine on the composition of (water + alcohol) mixtures at 298.15 K

• Published in: Thermochimica acta 2011-09, Vol.524 (1), p.35-38
• Main Authors: Smirnov, Valeriy I., Badelin, Valentin G.
• Format: Article
• Language: English
• Subjects: Enthalpies of solution and transfer; Peptides; Solutions in aqueous alcohols
• ISSN: 0040-6031; 1872-762X
• DOI: 10.1016/j.tca.2011.06.008

• Enthalpies of dissolution of β-alanyl-β-alanine are measured in aqueous methanol, ethanol, 1-propanol and 2-propanol by calorimetry. • Standard values of dissolution and transfer enthalpies of β-alanyl-β-alanine and enthalpy coefficients of pair-wise interactions are calculated. • Dependences of the thermodynamic characteristics of dissolution of β-alanyl-β-alanine on the composition of (water + alcohol) mixtures are determined. The dissolution enthalpies of β-alanyl-β-alanine in aqueous methanol, ethanol, 1-propanol and 2-propanol solutions with an alcohol content up to 0.4 mole fractions have been measured calorimetrically at T = 298.15 K. The standard enthalpies of dissolution, Δ sol H° and transfer, Δ tr H°, of β-alanyl-β-alanine from water into mixed solvents and the enthalpy coefficients of pair-wise interactions, h xy , of β-alanyl-β-alanine with alcohol solvent molecules have been calculated. The results are discussed in terms of solute–solute and solute–solvent interactions.