Electrostatics of solvation of polyatomic species in a continuous medium. Solvent effects in electronic spectra

Abstract

The exact solution of the Poisson–Laplace equations for the electrostatic energy of an arbitrary system of point charges within a spherical cavity in a dielectric medium is given as an infinite series. It is shown that the exact formula can be closely approximated by a simple algebraic expression. The equations are applied to the solvation of polyatomic species in organic solvents and new formulae are given for the effect of the dielectric medium on the electronic spectra of such species.

Calculations are carried through for alkali-metal p-benzoquinone ion pairs and it is concluded that the large solvent shifts observed experimentally for alkali-metal benzophenone ketyls arise from solvent perturbation of the electronic energy levels and are not (as has been suggested previously) due to changes in interionic distance.