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.