Synlett 2005(14): 2117-2129  
DOI: 10.1055/s-2005-872238
© Georg Thieme Verlag Stuttgart · New York

Open-Cage Fullerenes: Synthesis, Structure, and Molecular Encapsulation

Sho-ichi Iwamatsu*, Shizuaki Murata
Graduate School of Environmental Studies, Nagoya University, Chikusa, Nagoya 464-8601, Japan
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Further Information

Publication History

Received 11 May 2005
Publication Date:
20 July 2005 (online)


The carbon-carbon bond scission of the fullerene cage offers an open-cage fullerene derivative having an opening on the fullerene surface. This account summarizes our recent studies on the syntheses of open-cage C60 derivatives as well as their properties of molecular encapsulation. The photochemical rearrangement of the cyclohexadiene derivative of C60 gives bis(fulleroid), the precursor for the cage scission. The photooxygenative carbon-carbon bond cleavage of bis(fulleroid) affords an open-cage diketone derivative having a 12-membered ring. The reaction of the diketone derivative with aromatic hydrazine or hydrazone allows the ring expansion of the orifice by regioselective cage scission to yield a product bearing a 16-membered ring. The orifice in the product is large enough to pass a hydrogen molecule, producing an endohedral hydrogen complex. In the case of the reaction with ortho-phenylenediamine, two carbon-carbon bonds are sequentially cleaved to afford a product having a 20-membered ring orifice. This product spontaneously encapsulates one water molecule to form an endohedral water complex.

  • 1 Introduction

  • 2 Preparation of Open-Cage Fullerenes

  • 2.1 Bis(fulleroid) Derivatives

  • 2.2 Open-Cage Diketone Derivative of C60

  • 2.3 Expansion of the Orifice of the Open-Cage Diketone C60 (1) The Reactions with Aromatic Hydrazines or Hydrazones

  • 2.4 Expansion of the Orifice of the Open-Cage Diketone C60 (2) The Reactions with Aromatic 1,2-Diamines

  • 2.5 Expansion of the Orifice of the Open-Cage Ketolactam C60

  • 3 Molecular Structures of the Open-Cage C60 Derivatives

  • 4 Molecular Encapsulations in the Open-Cage C60 Derivatives

  • 4.1 Hydrogen (H2)

  • 4.2 Water

  • 5 Conclusion and Future Aspects