Formation of Redox-Active, Two-Component Films by Electrochemical Reduction of C60 and Transition Metal Complexes

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• 作者：Alan L. Balch ; David A. Costa ; and Krzysztof Winkler
• 刊名：Journal of the American Chemical Society
• 出版年：1998
• 出版时间：September 23, 1998
• 年：1998
• 卷：120
• 期：37
• 页码：9614 - 9620
• 全文大小：150K
• 年卷期：v.120,no.37(September 23, 1998)
• ISSN：1520-5126

文摘

Electrochemical reduction of C₆₀ in 4:1 toluene/acetonitrile solution in the presence of (PhCN)₂PdCl₂, Ir(CO)₂Cl(p-toluidine), or (CF₃CO₂)₄Rh₂ produces three different, redox-active, black films that coatthe electrode. These films are insoluble in common organic solvents and adhere strongly to the electrodesurface. Film formation has been monitored by multiscan cyclic voltammetry, which gives information aboutthe requirements for film growth. The three different films (on the original electrodes) can be transferred toa solution of acetonitrile that contains only the supporting electrolyte, tetra(n-butyl)ammonium perchlorate,where the films retain their redox activity. Each film displays a significant decrease in resistivity (i.e. a windowof conductivity) in the potential region in which it is grown and in which it displays redox activity. The filmshave been examined by scanning electron microscopy, which shows variations in the nature of the three films'morphologies with the film formed from (PhCN)₂PdCl₂ displaying the greatest uniformity and smoothest surface.Analysis of the films by infrared spectroscopy and laser desorption mass spectrometry reveals that intact C₆₀units are present within each film. Treatment of the palladium/C₆₀ film with triphenylphosphine results infilm dissolution and the formation of the previously characterized complex, (²-C₆₀)Pd(PPh₃)₂. The rhodium/C₆₀ film dissolves in pyridine and ¹⁹F{¹H} NMR spectroscopy reveals that (CF₃CO₂)₄Rh₂ is extracted intactfrom the film. The structure of the films is discussed in terms of covalent bonding between the fullerenes andthe metal atoms or complexes within the film.