High-Resolution Electron Microscopy of C60 Clusters

Methods for the preparation of significant quantities of C60 clusters separated from carbon soot were recently reported by Krätschmer and co-workers. Evidence that these clusters have the “Buckminsterfullerene” structure with five-fold and six-fold carbon rings on the surface of a sphere (soccer-ball structure) has been provided by several techniques. NMR shows a single type of carbon bonding, and IR peaks consistent with modes characteristic of this system have been identified. Since C60 can be isolated and has stable “graphitic” bonding, it represents a unique opportunity to observe individual stable carbon molecules with transmission electron microscopy in order to test the morphology deduced from other techniques. Also, the study of packing sequences and defect structures in C60 crystals found by x-ray diffraction to have an FCC lattice constant of 1.41 nm provides important new information on variations of crystallization with conditions such as solvent type and crystallization rate.