Calorimetric study of nitrile group - Solvent interactions and comparison with dispersive quasi-chemical (DISQUAC) predictions

A flow microcalorimeter, model 2277-LKB, has been used to determine excess enthalpies, HE, at 298.15 K, for liquid mixtures containing ethanenitrile, propanenitrile, butanentrile, or pentanenitrile + benzene or tetrachloromethane. These experimental results together with the literature data on thermodynamic properties of alkanenitrile + benzene or tetrachloromethane mixtures have been interpreted in terms of the dispersive quasi-chemical (DISQUAC) group contribution model. Two sets of structure-dependent interaction parameters, for the nitrile group/aromatic and for the nitrile group/tetrachloromethane contacts, have been obtained. The model provides a fairly consistent description of the excess Gibbs energy, GE, excess enthalpy, HE, and of activity coefficients at infinite dilution, γi ∞, of the considered mixtures.