Limit to puckering of benzene with sterically crowded molecules: Hexaferrocenylbenzene

The resonance energies for the chair and boat puckering modes in benzene have been calculated through their hydrogenation energies. It is found that benzene retains its aromatic stabilization for distortions less than +0.3 angstrom/-0.3 angstrom and +0.3 angstrom/+0.3 angstrom for the chair and boat forms respectively. The calculated resonance energies and NICS for the benzene ring in hexaferrocenylbenzene (HFB) suggests that even though the benzene ring is puckered, it remains aromatic and thereby stable. (c) 2006 Elsevier B.V. All rights reserved.