David Manolopoulos (Department of Chemistry, University of Nottingham, England): "The summer of 1991 was an exciting time to study the fullerenes. The beautifully symmetric structures of the C60 and C70 molecules had recently been confirmed by infrared and 13C NMR spectroscopy, and preliminary spectroscopic results had been reported for C76, C78, and beyond. These latter results suggested that the larger carbon clusters were also likely to be fullerenes, but they were not sufficiently resolved to characterize their precise structures (F. Diederich, et al., Science, 252:548, 1991). Our two papers addressed the question of these structures by using a simple computer program for generating fullerene polyhedra in conjunction with qualitative molecular orbital theory.
"The results were unexpected and interesting. C76 was found to have just two isolated-pentagon fullerene isomers, one with cubic Td and the other with chiral D2 symmetry. Huckel molecular orbital calculations revealed that the Td isomer would be ...
