Abstract
A specific interaction between an electron acceptor A and an electron donor D can be at the origin of the formation of ions. In most cases however the ions are not A^−^ and D^+^ but their formation results from the weakening of a chemical bond in the electron acceptor molecule as a consequence of the formation of the specific bond and the subsequent breaking of this bond leaving the entities A'^−^ and p^+^ ‐D, p^+^ being a positive ion. The transfer of p^+^ from A'^−^ to D causes an increase of the dipole moment of the complex and an important decrease of its volume which is not restricted to the region of the specific bond itself. This transfer is influenced by changes in the dielectric constant of the medium but also even to a greater extent by further specific interactions between the partners and the surrounding molecules. These two factors also play a role in the dissociation of the ion‐pairs. However, it is shown that in many cases the possibility of formation of supplementary specific bonds rather disfavours the dissociation because they stabilize more the ion‐pairs than the free ions.