Chen Dandan, Szczepanik Dariusz W, Zhu Jun, Muñoz-Castro Alvaro, Solà Miquel
State Key Laboratory of Physical Chemistry of Solid Surfaces and Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), Fujian Provincial Key Laboratory of Theoretical and Computational, Chemistry and Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, 361005, Xiamen, P.R. China.
Institute of Computational Chemistry and Catalysis and Department of, Chemistry, University of Girona, C/M. Aurèlia Capmany, 69, 17003, Girona, Catalonia, Spain.
Chemistry. 2021 Jan 7;27(2):802-808. doi: 10.1002/chem.202004322. Epub 2020 Dec 4.
The isolated-pentagon rule (IPR) is a determining structural feature that accounts for hollow fullerene stabilization and properties related to C (n≥60) cages. The recent characterization of an unprecedented non-IPR hydrofullerene, C C H , bearing two heptagons with adjacent fused-pentagon motifs, largely dismisses this feature. Herein, employing DFT calculations, the C NMR spectroscopy and aromatic behavior of C C H are explored. The results show the presence of three π-aromatic circuits at the bottom boat section of C H , indicating the unique features of this hydrofullerene in comparison to those of pristine C . In addition, under specific orientations of the external field, certain π-aromatic circuits are enabled, resulting in a more aromatic fullerene than that of C , but lower than that of the spherical aromatic C fulleride. Notably, under a field aligned with the saturated carbon atoms, nonaromatic 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.
孤立五边形规则（IPR）是一种决定结构的特征，它解释了中空富勒烯的稳定性以及与C（n≥60）笼相关的性质。最近对一种前所未有的非IPR氢化富勒烯C C H 的表征发现，它带有两个具有相邻稠合五边形 motif 的七边形，这在很大程度上否定了这一特征。在此，采用密度泛函理论（DFT）计算，对C C H 的 C 核磁共振光谱和芳香行为进行了探索。结果表明，在C H 的底船部分存在三个π-芳香回路，这表明这种氢化富勒烯与原始C 相比具有独特的特征。此外，在外场的特定取向下，某些π-芳香回路被激活，导致形成一种比C 更具芳香性的富勒烯，但比球形芳香C 富勒化物的芳香性低。值得注意的是，在与饱和碳原子对齐的场下，非芳香特性会显现出来。这表明类球形笼可能涉及复杂的磁响应，这在很大程度上取决于所施加场的取向。
