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Updated: May 8, 2026

Preparation of a Corannulene-functionalized Hexahelicene by Copper(I)-catalyzed Alkyne-azide Cycloaddition of Nonplanar Polyaromatic Units
Published on: September 18, 2016
Theoretical study on the conformation and aromaticity of regular and singly N-confused [28]hexaphyrins
Motoki Toganoh1, Hiroyuki Furuta
1Department of Chemistry and Biochemistry, Graduate School of Engineering, and ‡Center for Molecular Systems, Kyushu University , 744 Moto-oka, Nishi-ku, Fukuoka 819-0395, Japan.
Abstract:
Structures and electronic states of regular and singly N-confused [28]hexaphyrins(1.1.1.1.1.1) were thoroughly studied with the aid of DFT calculations. To obtain systematic information, all the conceivable structures (450 structures in total) were examined. Unlike the [26]hexaphyrins(1.1.1.1.1.1) reported previously (J. Org. Chem. 2010, 75, 8213-8223), the electronic states of [28]hexaphyrins were highly affected by their conformations. The planar conformers (dumbbell, rectangular, triangular) show Hückel antiaromaticity, while the singly twisted conformers show Möbius aromaticity. Figure-eight structures correspond to the doubly twisted structures and show nonaromaticity. Disruption of annulenic circuits in singly N-confused [28]hexaphyrins caused weakening of both aromatic and antiaromatic characteristics. Relative stabilities among conformers were mainly governed by the intramolecular hydrogen bonds and secondarily affected by the steric factors. In addition, interconversion pathways among conformers were proposed on the basis of calculations on singly N-confused [28]hexaphyrins.
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