Carbon Monoxide Inside an Open-Cage Fullerene

摘要

The chemistry of fullerenes that encapsulate molecules or atoms (endohedral fullerenes) has developed extensively in the last decade. A high-pressure, high-temperature method has made it feasible to insert atoms and some small molecules into fullerene cages.[1] However, the yield of the incorporated product obtained by this method is very low. In an attempt to prepare endohedral fullerenes in higher quantities, carbon-carbon bonds of fullerene cages have been cleaved by organic reactions.[2]-[4] The resulting product, a so-called open-cage fullerene, has an opening that is large enough to insert an atom or a molecule into the cavity of the fullerene.[5]-[9] Unlike complete endohedral fullerenes, these derivatives can hold and release substrates in a reversible manner. This property offers sensing and storage materials as potential applications.[10] Furthermore, an open moiety can be restored to an intact cage with the inserted chemical species inside. Indeed, pure endohedral H2@C60 was recently synthesized from C60 by using this strategy.