Minit Buckyball Resonance

The C60 molecule, aka buckyball is a symmetrical (point group Ih), spherical fullerene made up of 60 carbon atoms. Its shape resembles a soccer ball which can be described as a truncated icosahedron. The carbon atoms are arranged as 12 pentagonal & 20 hexagonal rings where no two pentagons share an edge. This minimizes physical strain while enhancing chemical stability.

This physical model uses trigonal atoms which are sp2 hybridized that form three sigma bonds with adjacent carbon atoms. The remaining unhybridized pzp_zpz orbital on each carbon atom participates in a delocalized πpiπ-electron system. The model is shown with 15mm bonds connected additionally with "x-pegs". This closely approximates the scales of 1.45? & 1.4? but 20mm bonds can be used to differentiate if preferred.

The C60 buckyball molecule exhibits resonance due to the delocalized πpiπ-electron system spread over the entire structure. This resonance is non-aromatic unlike benzene as it does not have a uniform distribution of πpiπ-electrons. This is because they are not equally delocalized because of the mixed pentagonal and hexagonal ring system. Hence, the molecule can be considered super-conjugated, where electron density alternates to stabilize the entire structure.

Because the C60 buckyball acts as an electron acceptor it has uses in photovoltaics and electron transport materials. This delocalized πpiπ ring system has unique electronic transitions as indicated by its characteristic UV-vis spectroscopic absorption spectrum.