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

Nature volume 407, pages 6063 (07 September 2000) | Download Citation

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Abstract

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 C20H 20) 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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References

  1. 1.

    Smaller carbon species in the laboratory and in space. Int. J. Mass Spectrom. Ions Process. 138, 1– 15 (1994).

  2. 2.

    & Small carbon clusters. Spectroscopy, structure, and energetics. Chem. Rev. 98, 2313–2357 (1998).

  3. 3.

    et al. UPS of 2–30-atom carbon clusters: Chains and rings. Chem. Phys. Lett. 144, 431–436 (1988).

  4. 4.

    et al. Stable configurations of carbon clusters: Chains, rings, and fullerenes. Phys. Rev. Lett. 74, 1095– 1098 (1995).

  5. 5.

    et al. Photoelectron spectroscopy of C-n produced from laser ablated dehydroannulene derivatives having carbon ring size of n = 12, 16, 18, 20 and 24. J. Chem. Phys. 107 , 4783–4787 (1997).

  6. 6.

    et al. Do small fullerenes exist only on the computer? Experimental results on C+/-20 and C+/-24 . Chem. Phys. Lett. 204, 15– 22 (1993).

  7. 7.

    & Reflections on Symmetry (VCH, Weinheim, 1993).

  8. 8.

    , & Experimental evidence for the formation of fullerenes by collisional heating of carbon rings in the gas phase. Nature 363, 60–63 ( 1993).

  9. 9.

    The stability of the fullerenes Cn, with n = 24, 28, 32, 36, 50, 60 and 70. Nature 329, 529– 531 (1987).

  10. 10.

    , & C36, a new carbon solid. Nature 393, 771–774 ( 1998).

  11. 11.

    et al. C36, a hexavalent building block for fullerene compounds and solids. Chem. Phys. Lett. 300, 369–378 (1999).

  12. 12.

    , , & A preparative scale synthesis of C36 by high-temperature laser vaporization: Purification and identification of C36H6 and C 36H6O. J. Am. Chem. Soc. 122, 398–399 (2000).

  13. 13.

    & R. In-plane aromaticity and trishomoaromaticity: A computational evaluation. J. Org. Chem. 51, 4357–4368 ( 1986).

  14. 14.

    , & The pagodane route to dodecahedranes: An improved approach to the C20H20 parent framework; partial and total functionalizations—does C20-fullerene exist? Angew. Chem. Int. Edn Engl. 32, 1722–1726 (1993).

  15. 15.

    & From an insecticide to Plato's Universe—the pagodane route to dodecahedranes: New pathways and new perspectives. Angew. Chem. Int. Edn Engl. 33, 2239– 2257 (1994).

  16. 16.

    et al. From pagodanes to dodecahedranes—search for a serviceable access to the parent C20H20 hydrocarbon. Tetrahedron 53, 10029–10040 (1997).

  17. 17.

    , & Steric overcrowding in perhalogenated cyclohexanes, dodecahedranes, and [60]fulleranes. J. Am. Chem. Soc. 17, 10381–10384 (1995).

  18. 18.

    et al. Experimental enthalpies of formation and strain energies for the caged C20H20 pagodane and dodecahedrane frameworks. J. Am. Chem. Soc. 116, 11775–11778 (1994); 117, 8885 (1995).

  19. 19.

    et al. Unsaturated dodecahedranes - synthesis of the highly pyramidalized, highly reactive C20H18 and C20H16 olefins. Res. Chem. Intermed. 22, 667– 702 (1996).

  20. 20.

    et al. Corannulene. A three-step synthesis. J. Am. Chem. Soc. 119, 10963–10968 ( 1997).

  21. 21.

    , & Vibrational and electronic properties of neutral and negatively charged C20 clusters. Phys. Rev. B 57, 1860–1867 (1998).

  22. 22.

    & Bond lengths and reorganization energies in fullerenes and their ions. Theor. Chem. Acc. 97, 110–118 ( 1997).

  23. 23.

    , , , & A double/triple time-of-flight mass spectrometer for the study of photoprocesses in clusters, or how to produce cluster ions with different temperatures. Rev. Sci. Instrum. 62, 2621–2625 (1991).

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Acknowledgements

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, 79104 Freiburg, Germany

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

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

    • Daniela Olevano
    •  & Bernd v. Issendorff

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Correspondence to Horst Prinzbach.

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https://doi.org/10.1038/35024037

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