Premium
On the 13 C‐NMR chemical shift anisotropy patterns and aromatic character in strained fullerenes: Computational analysis of D 6h / D 2d ‐C 36 fullerene
Author(s) -
GuajardoMaturana Raul,
RodríguezKessler Peter L.,
MacLeodCarey Desmond,
MuñozCastro Alvaro
Publication year - 2021
Publication title -
international journal of quantum chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.484
H-Index - 105
eISSN - 1097-461X
pISSN - 0020-7608
DOI - 10.1002/qua.26437
Subject(s) - fullerene , chemistry , crystallography , planar , anisotropy , raman spectroscopy , curvature , charge (physics) , character (mathematics) , symmetry (geometry) , electron , chemical physics , computational chemistry , geometry , physics , organic chemistry , optics , mathematics , computer graphics (images) , computer science , quantum mechanics
The NMR characterization of small C 36 hollow fullerene exposes a stable cage with structural features based on its strained curved π‐surface in a D 6h ‐symmetry. Our results indicate that planar‐like aromatic properties of the D 6h ‐C 36 isomer decrease to a nonaromatic cage for D 2d ‐C 36 after Stone‐Wales transformation of an equatorial [6.6] bond. This is given by the decrease of conjugation in the strained π‐surface after Stone‐Wales transformation. Calculated nuclear shielding shows that the main shielding component is always oriented perpendicularly to the cage π‐surface despite the larger curvature degree, as a result of the sp 2 character of carbon atoms, resembling C 60 . Moreover, the D 6h ‐ and D 2d ‐C 36 cages differ in their charge distribution properties, leading to charge accumulation in the strained cap of the former that leads to a polymerization‐prone cage, which contrasts with that expected for the D 2d structure. Hence, structural rearrangements of these non‐Hirsch aromatic fullerenes show that their inherent global behavior requires considering the structural features besides electron counting rules.