Is peri hydrogen repulsion responsible for flattening buckybowls? The effect of ring annelation to the rim of corannulene

B3LYP/6-31G* calculations indicate that annelation of three-, four-, or five-membered rings to the rim of corannulene results in lowering the bowl-to-bowl inversion barrier and flattens the bowl structure. The role of the peri hydrogen repulsion as a causative factor for such a behavior is disputed, the structure–energy relationships in this class of compounds were shown to fit with a mixed quartic–quadratic potential.