The cyclic voltammetric behavior of 1,3-diferrocenyl-2-buten-1-one (abbreviated as DFcB), a novel molecule with two electrochemically nonequivalent redox centers, was investigated by the thin-layer method, a simple protocol reported recently for studying electron transfer reactions at liquid/liquid interfaces. The bimolecular rate constants for the two-step electron transfer reactions between DFcB in the organic phase and [Fe(CN)(6)](4-) located in the adjacent aqueous phase were obtained simultaneously at a single interface. The observed clear dependence of the rate constants on the overall driving force (dominated by the apparent formal potentials of the ferrocenyl groups in DFcB) is consistent with previous studies and qualitatively in agreement with the conventional Butler-Volmer treatment. The results demonstrate the feasibility of using molecules containing multiple redox centers to study the correlation between the thermodynamic driving force and electron transfer kinetics at liquid/liquid interfaces.