A New Bowl-shaped Subunit of Fullerene C70
Chair for Molecular Functional Materials
Published on in NEWS
Total synthetic approaches of fullerenes are a holy grail for organic chemistry. So far, the main attempts have been focused on the synthesis of the buckminsterfullerene C60. In contrast, access to subunits of the homologue C70 remains challenging. Here, we demonstrate an efficient bottom-up strategy towards a novel bowl-shaped polycyclic aromatic hydrocarbons (PAH) C34 with two pentagons.
This PAH represents a subunit for C70 and also of other higher fullerenes. The bowl-shaped structure was unambiguously determined by X-ray crystallography. Especially, a bowl-to-bowl inversion for a C70 fragment in solution was investigated by dynamic NMR analysis, showing a bowl-to-bowl inversion energy (ΔG‡) of 16.7 kcal mol-1, which is further corroborated by DFT calculations.
Link to: ACS Publications JACS