Electron transfer and structural change: distinguishing concerted and two-step processes.
In electron-transfer reactions accompanied by structural changes, the structural change can be concerted with electron transfer or can occur in a separate reaction either preceding or following the electron-transfer step. In this paper we discuss ways of distinguishing concerted reactions from the latter two-step type. Included are recent examples in which no intermediates have been detected in the reactions, thus precluding the direct assignment to the two-step category. In these cases, other means are used to build support for the two-step mechanism with respect to the concerted process. These include an example of structural change preceding electron transfer, a demonstration that the current models of concerted reactions cannot fit the voltammetric data, and a case in which an independent measure of the inner reorganization energy was used to show that the reaction could not be a concerted electron transfer and structural change.
Macías-Ruvalcaba
Norma A
NA
Facultad de Química, Universidad Nacional Autónoma de México, México, D. F. 04510, México.
Evans
Dennis H
DH