Solvent effects in extraction of carboxylic acids

A systematic analysis of experimental data on extraction of carboxylic acids with organic solvents indicates that nonspecific intermolecular interactions are better described by binary interaction potentials of London - Debye - Keesom than by continuum solvent models. The results point to a comparable importance of dispersive, inductive, and dipole-dipole interactions between the molecules of a solvent and the extracted species. The deviation of the experimental values for the distribution constant from the corresponding theoretical values, calculated under the assumption that the extracted substance and the extractant do not form complexes, allows the estimation of the energy of specific intermolecular interactions. A method, which permits identification of the contributions of nonspecific and specific intermolecular interaction between extracted and extractant molecules to the distribution constant, is suggested.