Electrochemical studies on bis(pentahaptocyclopentadienyl)iron encapsulated in aqueous Triton X-IOOmicelles

Abstract

Electrochemical studies on bis(pentahaptocyclopentadienyl)iron (ferrocene) have been carried out in aqueous solutions of Triton X-100 micelles. The ferrocene/ferricinium couple isreversible with the E^o’ value at + 0.216 ± 0.006V depending on various conditions of added electrolyte and ionic strength of the media. Compared to the values in nonaqueous media, the E^o’ value shows cathodic shift of ~ 260 mV.The diffusion coefficient (D_o) values of ferrocene in micelles (0.5-1.2 x 10^-6cm²sec^-1) are much smaller than those in nonaqueous media (e.g. in DMF D_o is 11.2 x 10 cm²sec^-1). The heterogeneous electron transfer rate constants (k) are found to be in the range 7.9-12.5 x 10^-3 cm sec^-1 in the surfactant solution.