Opals in a New Light

F rom graphite, to fullerene (C,,), and figure). The cubic graphite structure made on to carbon nanotubes, the number by Zakhidov et ccl. is special because the of intriguing material properties graphite sheets of ordered carbon atoms grows with the number of carbon atoms in are themselves ordered with the symmetry the building blocks. This sequence has of the dissolved face-centered cubic col-now been extended with “cubic graphite, ” loidal crystal array (I). a structure with a unit cell of several hun- These regular macroporous materials dred nanometers. On page 897 of this is- form a natural extension of the recently sue (l), Zakhidov et al. describe the syn- developed molecular templating tech-thesis of a conductive, graphite “inverse niques from liquid-crystalline surfactant opal ” together with similar structures con- phases to make mesoporous materials. As sisting of amorphous carbon and diamond such, they are important for processes made with artificial opals as the template. such as catalysis, sorption, and separation. These regular carbon structures hold great It is just a matter of time until the method nromise as both macronorous materials to make mesoporous structures is com-and photonic crystals. L Natural opals consist of a