Solvation energy of ions in dipolar solvents

Abstract

The solvation energy of hard spherical ions immersed in dipolar hard sphere solvents is investigated as a function of ion diameter. We apply both the mean spherical and linearized hypernetted-chain approximations and show that for ions of physically realistic size both theories give qualitatively similar results. The ion solvation energy is obtained as the sum of two competing terms: UID, the direct ion–solvent interaction energy, which is negative, and UDD, the change in the solvent–solvent interaction energy per ion at infinite dilution. UDD is found to be positive and to make an important contribution to the solvation energy for all ion diameters.

Statistical Mechanical Theory of the Partial and Other Derivatives of Thermodynamic Quantities of Liquid Mixtures

“…Patey et al 3 have obtained an integral equation of the number density derivatives of radial distribution functions and calculated the solvation energy for Lennard-Jones mixtures and ionic solutions under the condition of constant volume. Karplus et aL4 have also studied solutions of argon or monoatomic ions and a waterlike solvent.…”

Estimation of the outer-sphere contribution to the activation parameters for homogeneous electron-transfer reactions using the mean spherical approximation

“…However, the predominant contribution to AGos comes from the term at optical frequencies because the optical permittivity in all polar solvents is much less than the static value. The MSA model which was derived for systems with permanent dipole moments embedded in hard spheres [10][11][12] is not appropriate at these high frequencies where the electrical property of importance is the molecular polarizability.…”

“…Differentiating eq. (8) (10) It is interesting to estimate AGos for the redox reactions involving cobaltacene (COB). This system can be oxidized to form the corresponding cation radical or reduced to form the anion radical (15].…”

Estimation of the Outer Sphere Contribution to the Activation Parameters for Homogeneous Electron Transfer Reactions Using the Mean Spherical Approximation

“…When one uses the MSA to estimate the static contribution to the Gibbs solvation energy, the expression for AGs,st becomes [7,10,11]…”