Concerning the distant polar interaction in free energies of transfer. An explanation and an estimation procedure

Abstract

For polyfunctional compounds, free energies of transfer from gas to aqueous solution require corrections for the interactions of polar groups (Distant Polar Interactions). These corrections can be made with very few adjustable parameters by using a model of the solvation process assuming hydrogen bonding is the major source of the effect on free energy of transfer for polar groups, and that hydrogen bonding is perturbed by polar effects, measured by Taft σ*. Parameters evaluated for polyfluoro, polychloro, and polybromo compounds successfully predicted the free energies of transfer for mixed polyhalogen compounds. Preliminary parameters have been evaluated for ethers, amines, phenyl groups, nitriles, and esters. Key words: free energy of transfer, distant polar interaction, hydrogen bonding, solvation.