Shape and Fantasy of Fullerenes

Abstract

One of the many wonders that fullerenes have brought to us during the past few years is the variety of their shapes. When the elusive C60 finally showed up in 1990, the perfect symmetry and astounding beauty of its molecular structure touched the hearts of scientists before they could consider the molecule's vast technical possibilities. Already much has been said about the unique shape of C60 and its potentialities. C70 and higher fullerenes have simultaneously been found in the same soot that produced C60 and were quickly revealed to be shaped like rugby balls or oblong eggs. Hence we were aware that there had to be an extensive series of roundish polyhedral clusters of carbon atoms.Then, in the following year, multilayered tubular fullerenes (Figures 1a and 1b) were discovered by Iijima and were named buckytubes (see the article by Iijima in this issue). Iijima also observed similarly huge and multilayered carbon balls, before C60 was discovered. Soon after, buckyonions were recognized as an important class of fullerene (Figure 1c, see article by Ugarte in this issue). So, in the early days of fullerene research, we already knew three forms of fullerene: sphere, tube, and particle. At that time, however, nobody anticipated that this was only the beginning of a big show of stunning variations in the shapes of fullerenes. This article introduces current developments in the study of these fullerene styles.

Graphite Polyhedral Crystals

“…GPCs represent a group of low-dimensional crystals with a variety of shapes, some of which were predicted [toroidal shape (25)] or experimentally observed in nanotubes (26), but have never been reported on the size scale or in the amounts that we found. It is probably not surprising that carbon, with its ability to exist in so many allotropic forms, produces a crystalline morphology not observed for other materials.…”

Enumeration of periodic tetrahedral frameworks

“…With the recent discovery of carbon fullerene molecules, which are formed from closed 3-connected nets, and which include the celebrated Cgo molecule [61] and the carbon nanotubes [62,63], there has been interest in the possibility of forming open 3-dimensional, 3-and 4-connected carbon frameworks [64][65][66][67]. The hyperbolically-curved 3-connected graphitic nets would require the presence of 7-rings or larger, as well as the 5-and 6-rings found in the fullerenes.…”

Mechanism of Supramolecular Polymerizations

“…Macroscopic analogies may be found in the growth of corals, branching of trees, and nesting of spheres into a large sphere, and so on. [81] E. Liquid Crystallinity [79] The pentagons determine the curvature of the network and stabilize the discocythe shape of the erythrocytes.…”