Influence of charged microenvironment on redox potential and diffusion coefficient of [Fe4S4(SPh)4](NBu4)2 in DMF and inside CTAB film on electrode surface

Redox potential of [Fe4S4(SPh)4]2–/3–, a model of the active centre of ferredoxin, in DMF solution shows a 90-mV positive shift, when the charged microenvironment provided by the surfactant is changed from negative to positive. Inside the positive surfactant film on GC electrode there is a 235-Mv positive shift in redox potential compared to that in neutral DMF solution. Diffusion coefficient of the reduced cluster onto the electrode surface is also found to be 102 times greater in the presence of negative surfactant compared to that in positive surfactant.