Enthalpies of solution of DL-alpha-Alanyl-DL-alpha-Valine in aqueous solution of amides at 298.15 K

摘要

The enthalpies of solution of DL-alpha-Alanyl-DL-alpha-Valine in aqueous solution of formamide, N-methylformamide, N,N-dimethylformamide, N,N-diethylformamide and N,N-dimethylacetamide were determined by calorimetry at 298.15 K over the concentration range x(2) = 0-0.4 mole fractions. Standard enthalpies of solution Delta H-sol(m)degrees, and transfer Delta H-tr(m)degrees from water to mixed solvents were computed. The enthalpy coefficients of pairwise DL-alpha-Alanyl-DL-alpha-Valine-amide interactions were calculated. The interrelation between the enthalpy characteristics of solution (transfer) of DL-alpha-Alanyl-DL-alpha-Valine and the structure and physicochemical characteristics of solvents, as well as the composition of mixtures were revealed.