Recent rate data for very fast cleaving of aryl chloride and bromide anion radicals may be accommodated satisfactorily within rate constant versus ArX/ArX.- standard potential existing correlations provided the standard potential is determined experimentally. Cyclic voltammetry is used for this purpose, taking careful account of the electron transfer/fragmentation reaction mixed character of the kinetics. The ensuing activation/driving force relationships allow the determination of the intrinsic barriers, the magnitude of which are discussed in the framework of a new Morse curve model that includes and emphasizes the role of bond bending.