Steric and inductive effects in binary mixtures of alkanones with benzene or tetrachloromethane. Comparison with DISQUAC predictions

Literature data on molar excess enthalpies (HE), molar excess Gibbs energies (GE) and activity coefficients at infinite dilution (γi∞) of linear alkanones+benzene or tetrachloromethane are treated in the framework of DISQUAC, an extended group contribution model. The systems are characterized by three types of contact surfaces: carbonyl (CO group), alkane (CH3 or CH2 groups) and solvent (benzene, C6H6, or tetrachloromethane, CCl4, groups). The interchange energies parameters of the alkane/CO and alkane/solvent contacts were determined previously, the interaction parameters of the CO/solvent contacts are reported in this work. The quasi-chemical and dispersive parameters depend on the environment of the CO group. The model provides a fairly consistent description of the experimental data as a function of concentration. The solutions of alkanones in benzene or tetrachloromethane exhibit the features of polar solute+polarizable solvent mixtures, namely, the deviations from ideality are much less positive than in alkanes and may even be negative.