Investigation of the effects of metalloporphyrin species containing different substitutes on electron transfer at the liquid/liquid interface

Scanning electrochemical microscopy (SECM) technology has been used to investigate the kinetics of heterogeneous electron transfer (ET) as a function of driving force at the interface between two immiscible electrolyte solutions (ITIES). The ET between metalloporphyrin species containing different substitutes in nitrobenzene and other redox species in the aqueous phase was studied and the rate constants were also extracted from the dependence of the steady-state current at a micrometer-sized tip electrode on the distance between the tip and the phase boundary when compared with the theoretical working curves. Corresponding to the various metalloporphyrin substitutes, SECM was demonstrated to be a useful means to study the effect of molecular structure on the kinetics of heterogeneous ET.