Triad and cyclic diad compounds of fullerene with metallocenes†
Metallocene-bridged fullerene triads and cyclised metallocene-fullerene diads are formed via [3 + 2] cycloaddition reactions of fullerene with metallocene dialdehyde and an amino acid. In the case of cyclic diads only one regioisomer is formed, as determined by UV-vis and NMR spectroscopic studies. These compounds have both electron donor (metallocene) and acceptor (fullerene) components and give three electrochemically reversible one-electron reductions for each fullerene moiety. For the ferrocene-containing compounds, an electrochemically reversible one-electron oxidation process is observed, with an irreversible oxidation observed for the ruthenocene analogues.