Structural-thermodynamic characteristics and intermolecular interactions in mixtures of strongly associated solvents with aprotic amides

Thermodynamic characteristics of mixtures of aprotic amides with water and organic solvents with hydrogen bond networks are calculated. Within a model approach the specific and non-specific components of the total energy of the intermolecular interaction are determined, based on which the corresponding contributions to the enthalpies of component mixing are calculated. It is found that negative enthalpies of mixing in the mixtures under study are due to non-specific interactions rather than heterocomponent specific ones. It is shown that the difference in the structural-thermodynamic characteristics of aqueous and nonaqueous mixtures of aprotic amides is mainly caused by packing features of solutions and the behavior of hydrogen bond networks of water and organic solvents.