Behaviors of the Interfacial Consecutive Multistep Electron Transfer Controlled by Varied Transition Metal Ions in...

Almost all life activities involve the process of multistep electron transfer (ET) which occurs on biomembrane. Metalloporphyrins (MTPPs) are a class of molecules which are closely related to life course. Here, the n-step (n = 1, 2) ET behaviors controlled by different metal ions in porphyrin cores were investigated by thin-layer cyclic voltammetry (TLCV). The bimolecular ET was reacted between the MTPP (M = Fe, Zn, Co, Cu, Ni) and Fe(CN)₆^4- in nitrobenzene and aqueous phase, respectively, and the interface between nitrobenzene and aqueous phase was considered as a bionic membrane. The thin-layer theory, which has been revised, was used to calculate the kinetic constants for each step electron transfer reactions. It was shown that the kinetic data were affected dramatically by the different coordinated ions in porphyrin complexes.