The evolution of the football structure for the C₆₀ molecule: a retrospective

Summary

By chance in 1970, we conjectured the possibility of the football-shaped C₆₀ molecule, now known as buckminsterfullerene, while considering superaromatic molecules having three-dimensional π-electron delocalization. A translation of the original description, initially written in Japanese, is given. The processes leading to scientific discoveries are analysed in the light of our missed opportunity.

Introduction

The timescale of scientific and technological advance is becoming shorter and shorter in modern society, partly as a consequence of the rapid advance of technology and improving information transfer. It is no wonder then that the time has come to look back and discuss the future of fullerene science after less than a decade since its discovery by Kroto et al. (1985) and after only two years since it was isolated by Kratchmer et al. (1990). The purpose of this paper is to recount the story of original early proposal of the football-shaped C₆₀ molecule back in 1970, and refer to other interesting ‘prehistoric’ events and analyse the process of scientific discovery.

Background

In the 1960s and 1970s, non-benzenoid aromatics were favourite targets for organic chemists. There was a prevailing dogma that aromaticity, due to the delocalization of π-electrons, is best realized in planar molecules. Everyone wished to constrain their molecules to be as planar as possible and for this reason aromaticity tacitly remained a two-dimensional concept. [18]Annulene (1), synthesized by Sondheimer et al. (1962), can be regarded as the masterpiece of planar aromaticity for its symmetric beauty (D_6h) and high level of π-electron delocalization. In view of the wide availability and its perfect aromaticity, however, benzene remains the archetypal superstar of aromatic molecules.