The structural and electronic stabilities of the title compound have been investigated in CH3CN---CH3OH (100-0% to 0-100%) and in aqueous Triton X-100 micelles, by cyclic voltammetry and electronic absorption and EPR spectroscopies. The iron-sulfur cluster has been located in the peripheral polar zone of the micelle, where H2O molecules are also present. When incorporated in the micelle, the cluster shows satisfactory stability and appears to react, at its most reduced state, with the unsaturated substrate 4-methyl-l-cyclohexene.