Dynamic Structural Fluxionality in a Planar Tetracoordinate Carbon Cluster Stabilized by Boron Ligands.

Autor: Jin B; Department of Chemistry, Xinzhou Normal University, 034000, Xinzhou, Shanxi, People's Republic of China., Wang ZR; Department of Chemistry, Xinzhou Normal University, 034000, Xinzhou, Shanxi, People's Republic of China., Yan M; Department of Chemistry, Xinzhou Normal University, 034000, Xinzhou, Shanxi, People's Republic of China., Feng LY; Department of Chemistry, Xinzhou Normal University, 034000, Xinzhou, Shanxi, People's Republic of China., Miao CQ; Department of Chemistry, Xinzhou Normal University, 034000, Xinzhou, Shanxi, People's Republic of China., Wang YJ; Department of Chemistry, Xinzhou Normal University, 034000, Xinzhou, Shanxi, People's Republic of China.
Jazyk: angličtina
Zdroj: Chemistry (Weinheim an der Bergstrasse, Germany) [Chemistry] 2024 Sep 11; Vol. 30 (51), pp. e202402132. Date of Electronic Publication: 2024 Aug 22.
DOI: 10.1002/chem.202402132
Abstrakt: The design of boron-based molecular rotors stems from boron-carbon binary clusters containing multiple planar hypercoordinate carbons (phCs, such as C 2 B 8 ). However, the design of boron-coordinated phCs is challenging due to boron's tendency to occupy hypercoordinate centers more than carbon. Although this challenge has been addressed, the designed clusters of interest have not exhibited dynamic fluxionality similar to that of the initial C 2 B 8 . To address this issue, we report a σ/π doubly aromatic CB 2 H 5 + cluster, the first global minimum containing a boron-coordinated planar tetracoordinate carbon atom with dynamic fluxionality. Dynamics simulations show that two ligand H atoms exhibit alternate rotation, resulting in an intriguing dynamic fluxionality in this cluster. Electronic structure analysis reveals the flexible bonding positions of the ligand H atoms because they do not participate in π delocalized bonding nor bond to any other non-carbon atom, highlighting this rotational fluxionality. Unprecedentedly, the fluxional process involves not only the usual conversion of the number of bonding atoms, but also the type of bonding (3c π bonds ↔4c σ bonds), which is an uncommon fluxional mechanism. The cluster represents an effort to apply phC species to molecular machines.
(© 2024 Wiley-VCH GmbH.)
Databáze: MEDLINE
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