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Updated: Oct 26, 2025

Preparation of a Corannulene-functionalized Hexahelicene by CopperI-catalyzed Alkyne-azide Cycloaddition of Nonplanar Polyaromatic Units
Published on: September 18, 2016
Cage-Expansion of Fullerenes
Sheng Zhang1, Yoshifumi Hashikawa1, Yasujiro Murata1
1Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011, Japan.
Abstract:
Despite the first proposal on the cage inflation of fullerenes in 1991, the chemical expansion of fullerenes has been still a formidable challenge. Herein, we provide an efficient methodology to expand [60] and [70]fullerene cages by the inclusion of totally C5N unit, giving nitrogen-containing closed structures as C65N and C75N with double fused heptagons. This method consists of two steps commenced with the construction of an opening by the reaction with triazine as a C3N source, followed by the cage reformation using N-phenylmaleimide as a C2 source. We also synthesized endohedral cages, demonstrating that the encapsulated H2O molecule inside the C75N cage prefers the orientation which maximizes the intramolecular interaction with the carbon wall. Additionally, we revealed the existence of a through-space magnetic dipolar interaction between the encapsulated H2 molecule and the embedded N atom.
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