Medium effects on elementary charge transfer processes in liquid and solid environments

A systematic discussion of the effect of the medium on the elementary act of electron and proton transfer reactions is given. The effects due to the softening or freezing of different discrete or continuum vibrational modes are elucidated. The role of dielectric polarizability of the environment and its spatial dispersion and the influence of the ionic atmosphere are discussed for different reaction types. The options offered by biological macromolecules as the reaction medium are considered. Focus is put on the differences of reaction rates in liquids and solids with an emphasis on some counterintuitive effects, which follow from the detailed analysis.