In studying the role of solvation in redox processes we consider the influence of geometrical modifications in the discharge of monosolvated anion CN--H2O. We define as "efficient" those modifications whose energy cost is less than the lowering which is produced in the ionization potential. we conclude that in the above-mentioned species the redox process is enhanced by desolvation. We try to generalise the results for the "stable" anions and cations. © 1979.