Substitution of the cyclopentadienyl protons typically results in significant electronic and electrochemical changes in metallocenes as HOMO and LUMO energies are shifted. In classical acceptor-substituted compounds, e.g. haloferrocenes, the substituents mainly stabilize the HOMO while weakly destabilizing the LUMO, resulting in high redox potentials for the reversible redox couple Fe +II/+III . In silylated ferrocenes, e.g. [Fe(C5(TMS)H4)2] (0.01 V vs. FcH), similar redox potentials to those of unsubstituted ferrocene are observed. The electrochemical properties of the polysilylated metallocenes 3-6 were determined by cyclic voltammetry in THF and referenced against the FcH/FcH + redox couple. All compounds exhibit a reversible one-electron oxidation with half-wave potentials between E1/2 = 0.161 V and 0.172 V, indicating that the silyl groups do not affect the HOMO energies significantly.