Electron solvation dynamics in polar liquids

A hydrodynamic model of electron solvation in polar liquids is suggested. The electron is assumed to be localized within a spherical cavity in an ideal incompressible liquid. The solvation process is modelled by the contraction of the cavity size to its equilibrium value. The contraction dynamics are determined by the competition between the gain in electron-solvent interaction energy and increase in kinetic energy of the electron. An explicit expression for the timescale of the process is derived. Its dependence on the solvent density and polarity, external pressure and initial radius of the cavity is explored. The calculated timescale of the electron solvation in water is in agreement with experimental data. The theory predicts a small isotope effect (∼5%) on the electron solvation process in heavy water.