Isomeric and Structural Impacts on Electron Acceptability of Carbon Cages in Atom-Bridged Fullerene Dimers

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• 作者：Baoyun Sun ; Tongxiang Ren ; Xiaopei Miao ; Fucai Dai ; Long Jin ; Hui Yuan ; Gengmei Xing ; Meixian Li ; Jinquan Dong ; Fei Chang ; Jingbo Hu ; Hao Chen ; Feng Zhao ; Xueyun Gao ; Yuliang Zhao
• 刊名：Journal of Physical Chemistry C
• 出版年：2008
• 出版时间：January 24, 2008
• 年：2008
• 卷：112
• 期：3
• 页码：741 - 746
• 全文大小：164K
• 年卷期：v.112,no.3(January 24, 2008)
• ISSN：1932-7455

文摘

The electrochemical properties of the carbon-bridged fullerene dimers C₁₂₁(I), C₁₂₁(II), C₁₂₁(III), C₁₃₁, andC₁₄₁ were characterized systematically for the first time in this study. Cyclic voltammogram and differentialpulse voltammogram analyses revealed that they first underwent three reversible fullerene-unit-based reductionprocesses where each of the two carbon cages accepted one electron in each step and then possessed a differentdeep reduction sequence from the fourth to sixth reduction potentials of the fullerene cages. The electronicinteractions between cages in the atom-bridged dimers (e.g., C₆₀-C-C₆₀) were found to be different fromthose of dimers in which two cages were connected directly. Comparison studies of the redox properties ofthe five dimers revealed that the C₆₀ dimerization via [5.6]-[6.6] connection influenced the cage electronacceptability much more than that of [5.6]-[5.6] or [6.6]-[6.6] connections and the dimerization with C₇₀cages influenced the reduction potentials of dimerized products more potently than that with C₆₀ cages. Furtherresults from controlled potential electrolysis, high-performance liquid chromatography, matrix-assisted laserdesorption and ionization time-of-flight mass spectrometry, ultraviolet absorption spectral analyses demonstratedthe reduction processes and a dissociation of the dimers based on reductions. The theoretical understandingof the experiments was investigated by using time-dependent density functional calculations for the ionicstates of C₁₂₁(I, II, III)^n- with n = 0, 1, 2, 3, or 4.