Quantum collective model of ionic solvation

Abstract

This paper contains a quantum hydrodynamic and collective surface mode treatment of the internal dynamics of a solvated ion. The theory developed is particularly useful for the consideration of the influence which internal solvation degrees of freedom have on electron transfer rate and reaction processes. The model consists of two inter-penetrating fluids: one ionic and one solvent. In addition, as the solvated ion occupies space within a continuum dielectric, the surface of the ion is considered as composed partly of the dielectric medium. Thus, surface quadrupole and higher multipole oscillations reflect distortions in the medium; these distortions can accommodate the movement of species to and from the ionic inner solvation sphere. As a result, it is possible to account for changes in coordination and bonding which take place in a number of electron transfer reactions. In addition, the theory shows a good agreement with the observed far infrared spectra of simple solvated ions. Isotope and solvent effects are predicted accurately.