Thermochimica Acta, Vol.520, No.1-2, 153-155, 2011
Enthalpies of solution of glycylglycylglycine in aqueous solution of amides at 298.15 K
Calorimetric measurements have been carried out at 298.15 K in aqueous solutions of glycylglycylglycine containing formamide, N-methylformamide, N,N-dimethylformamide and N,N-diethylformamide at concentrations of amides as co-solvents up to 0.4 mole fractions. The results obtained have been used to calculate the standard enthalpies of solution (Delta(sol)H degrees) and transfer (Delta(tr)H degrees) of the glycylglycylglycine from water into the mixtures as well as enthalpy coefficients of pair-wise interaction (h(xy)) of the solute with amide in aqueous media. The h(xy) values were correlated with the properties of organic solvents using Kamlet-Taft equation. The results of the calorimetric measurements have been discussed with regard to the intermolecular interactions occurring in these systems. (C) 2011 Elsevier B.V. All rights reserved.