ELECTRON-TRANSFER TO C-60 AND C-70 FULLERENES AT HYDRODYNAMIC AND DUAL ELECTRODES

The reductions of C60 and C70 fullerenes in o-dichlorobenzene (ODCB) electrolytes under controlled potential and convection at rotating disk and ring-disk electrodes (RDE and RRDE) illuminate several aspects of the electron transfer processes. The stability of the successive one-electron transfer products (up to C60(-3) and C70(-3) ions) is demonstrated through the RRDE. The diffusion coefficients of both fullerenes in ODCB/0.5M tetra n-butyl ammonium bromide were measured by two RDE techniques, Levich limiting current behavior and the frequency response of sinusoidal hydrodynamic modulation (SHM). The former gave values of 1.15 and 1.14 x 10(-6) cm2 /s at 25-degrees-C f or C60 and C70 respectively, and the latter results were theoretically consistent with the Schmidt number of 17,400 so calculated, confirming the number of electrons transferred without the aid of Faraday's law. Voltammograms of the SHM current at the RDE show kinetic effects at the foot of each successive wave.