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Preparation of a Corannulene-functionalized Hexahelicene by Copper(I)-catalyzed Alkyne-azide Cycloaddition of Nonplanar Polyaromatic Units
Published on: September 18, 2016
A C≡C Triple Bond as a Structural Anchor of Planar Pentacoordinate Carbon
Chagan Dari1, Guang-Ren Na1, Li-Juan Cui1
1Institute of Atomic and Molecular Physics, Jilin University, Changchun 130023, China.
None:
The potential energy surface of C2Li4H3- was examined to identify stable structures containing planar hypercoordinate carbon centers. The lowest-energy form corresponds to a C2v-symmetric arrangement in which a Li4H3 framework encloses a C≡C triple bond. Bonding analyses (NBO, AdNDP, EDA, and IQA) show that the system consists of a C22- fragment interacting mainly through electrostatic attraction and weak covalent contributions with the Li4H3+ unit. Magnetic response calculations indicate localized electron density supported by the C≡C bond, contrasting with the delocalization mechanisms typically invoked for planar hypercoordinate carbons. Born-Oppenheimer molecular dynamics simulations confirm structural stability under thermal conditions. These results outline an alternative electronic route to achieve planar pentacoordination in carbon systems.
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