The electrochemical properties of the carbon-bridged fullerene dimers C121(I), C121(II), C121(III), C131, and C141 were characterized systematically for the first time in this study. Cyclic voltammogram and differential pulse voltammogram analyses revealed that they first underwent three reversible fullerene-unit-based reduction processes where each of the two carbon cages accepted one electron in each step and then possessed a different deep reduction sequence from the fourth to sixth reduction potentials of the fullerene cages. The electronic interactions between cages in the atom-bridged dimers (e.g., C 60-C-C60) were found to be different from those of dimers in which two cages were connected directly. Comparison studies of the redox properties of the five dimers revealed that the C60 dimerization via [5.6]-[6.6] connection influenced the cage electron acceptability much more than that of [5.6]-[5.6] or [6.6]-[6.6] connections and the dimerization with C 70 cages influenced the reduction potentials of dimerized products more potently than that with C60 cages. Further results from controlled potential electrolysis, high-performance liquid chromatography, matrix-assisted laser desorption and ionization time-of-flight mass spectrometry, ultraviolet absorption spectral analyses demonstrated the reduction processes and a dissociation of the dimers based on reductions. The theoretical understanding of the experiments was investigated by using time-dependent density functional calculations for the ionic states of C 121(I, II, III)n- with n = 0, 1, 2, 3, or 4.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Physical and Theoretical Chemistry
- Surfaces, Coatings and Films