The deprotonation of the cation radical of 9-cyanomethylacridane by a series of normal bases is investigated and its pKa and homolytic bond dissociation energy determined experimentally. The latter parameter has the largest value in the NADH analogue series, thanks to the strong destabilization of the corresponding cation by the cyano group. It thus allows a significant extension of the attempted correlation between the intrinsic barriers and homolytic bond dissociation energies (D). Aside from members of the series where bulky substituents cause a decelerating steric effect, the correlation is close to a proportionality to D/4. The same correlation applies for all the other cation radicals where the rate constants of deprotonation by normal bases are available. The respective contributions of the homolytic and ionic states in the dissociation of the two types of acid, cation radicals and the conjugate acid of the normal base, are such that a simple model can be developed which regards the deprotonation r...