Transition state model for water exchange in the first solvation shell of hydrated cations according to quantum chemical calculations

Based on the theoretically calculated m.o. values for the binding energy of water molecules in the first and second solvation sphere of cations, the relation between bonding energies and experimentally observed hydration energies is discussed. Furthermore, the experimental values for the activation energy of water exchange in the first solvation layer are related to the binding energies of these water molecules, leading to strong support for an exchange mechanism involving the second hydration shell and a higher coordinated transition state.