Electrochemistry of C₆₀ films: Quartz crystal microbalance and mass spectrometric studies

The incorporation of tetra-n-butylammonium (TBA⁺) upon electroreduction of films of C₆₀ on an electrode in MeCN solutions was studied by electrochemical quartz crystal microbalance (EQCM) and laser desorption mass spectrometry (LDMS) methods. EQCM allowed estimation of the extent of dissolution of the films upon reduction to the C₆₀^- and C₆₀^2- forms and the increase in mass caused by incorporation of TBA⁺. LDMS analysis also indicated the presence of TBA⁺ after reduction. Both methods suggested that TBA⁺ remains in the lattice after reoxidation of the reduced forms to C₆₀, indicating a new type of "ionic charge trapping" in these films.