Aromaticity Survival in Hydrofullerenes: The Case of C66H4 with its π‐Aromatic Circuits

Abstract

The isolated‐pentagon rule (IPR) is a determining structural feature accounting for hollow fullerene stabilization and properties related to Cn (n ≥ 60) cages. The recent characterization of an unprecedented non‐IPR hydrofullerene, C2v‐C66H4, bearing two heptagons with adjacent fused‐pentagons motif, largely dismiss this feature. Herein, employing DFT calculations, we explore the 13C‐NMR pattern and aromatic behavior of C2v‐C66H4. Our results show the presence of three π‐aromatic circuits at the bottom boat section of C66H4 indicating the unique features of this hydrofullerene in comparison to pristine C60. In addition, under specific orientations of the external field, certain π‐aromatic circuits are enabled, resulting in a more aromatic fullerene than C60, but lower in comparison to the spherical aromatic C606‐ fulleride. Noteworthy, under a field‐aligned along with the saturated carbon atoms, non‐aromatic characteristics are exposed. This reveals that spherical‐like cages can involve a complex magnetic response that heavily depends on the orientation of the applied field