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Gas-phase production and photoelectron spectroscopy of the smallest fullerene, C20

Naturevolume 407pages6063 (2000) | Download Citation



Fullerenes are graphitic cage structures incorporating exactly twelve pentagons1. The smallest possible fullerene is thus C20, which consists solely of pentagons. But the extreme curvature and reactivity of this structure have led to doubts about its existence and stability. Although theoretical calculations have identified, besides this cage, a bowl and a monocyclic ring isomer as low-energy members of the C20 cluster family2, only ring isomers of C20 have been observed3,4,5,6 so far. Here we show that the cage-structured fullerene C20 can be produced from its perhydrogenated form (dodecahedrane C20H20) by replacing the hydrogen atoms with relatively weakly bound bromine atoms, followed by gas-phase debromination. For comparison we have also produced the bowl isomer of C20 using the same procedure. We characterize the generated C20 clusters using mass-selective anion photoelectron spectroscopy; the observed electron affinities and vibrational structures of these two C20 isomers differ significantly from each other, as well as from those of the known monocyclic isomer. We expect that these unique C20 species will serve as a benchmark test for further theoretical studies.

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We thank J. Leonhardt, G. Leonhardt-Lutterbeck, S. Ruf and C. Warth for technical assistance, and G. Seifert, S. Larsson and R. C. Haddon for discussions. This work was supported by the BASF AG, the Deutsche Forschungsgemeinschaft, the Fonds der Chemischen Industrie, and the US National Science Foundation.

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  1. Institut für Organische Chemie und Biochemie, Albert-Ludwigs-Universität, Freiburg, 79104, Germany

    • Horst Prinzbach
    • , Andreas Weiler
    • , Peter Landenberger
    • , Fabian Wahl
    •  & Jürgen Wörth
  2. Department of Chemistry, Boston College Merkert Chemistry Center, Chestnut Hill, 02467-3860, Massachussetts , USA

    • Lawrence T. Scott
    •  & Marc Gelmont
  3. Fakultät für Physik, Albert-Ludwigs-Universität , Freiburg, 79104, Germany

    • Daniela Olevano
    •  & Bernd v. Issendorff


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Correspondence to Horst Prinzbach.

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