Graphite, Buckyballs, and Nanotubes

Carbon exists as several allotropes, one of which is graphite. Graphite consists of sheets of carbon atoms that are all sp -hybridized [M Section 9.4]  

Intermolecular forces [Mt Chapter 11] hold the sheets together. Because of the delocalization of the electrons in the extended network of p orbitals perpendicular to the graphite sheet, graphite 

This pattern also resembles an architectural structure called a geodesic dome, so the Cgo molecule was named buckminstetfullerene in honor of R. Buckminster Fuller, the designer of the geodesic dome. The nickname for Qo is the buckyball. 

Since the discovery of Cgo, elongated and elliptical cages of 70 and 80 carbon atoms have also been discovered. These molecules, called fullerenes as a group, have been proposed to exist in such exotic places as stars and interstellar media and have been observed in such mundane places as deposits of chimney soot. 

Besides carbon, other elements have been fashioned into nanotubes, too. Molybdenum sulfide nanotubes have been synthesized, for example, with openings between atoms that are just the right size to permit some gas molecules to pass through, but not others. This may have potential for the nanoscale storage of gases for fuel cells. 

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