AbstractThe kinetics of the electron transfer reactions of aquoiron(III) with ferrocene (Fer) and its n‐butyl (BFer), 1,1′‐dimethyl (DMFer) and 1,1′‐di‐n‐butyl (DBFer) derivatives have been studied in the presence of cationic (CTAN) and non‐ionic (Triton X‐100) micelles at 20.0°C and ionic strength 0.02 mol dm−3. Both surfactants inhibit nearly at the same extent the reaction involving a given ferrocene derivative. The rate inhibition depends strongly on the alkyl groups present in the molecule of ferrocene, following the order DBFer>BFer>DMFer>Fer. The binding constants and the contribution of a methylene (or methyl) group of the alkyl substituents to the transfer free energy from water to micelle have been estimated and discussed, suggesting that ferrocenes are locate