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Updated: May 21, 2026

Spatial Separation of Molecular Conformers and Clusters
Published on: January 9, 2014
Three-Bladed Molecular Propellers: Design of Fluxional and Aromatic MB10O10- (M = Tc, Re) Clusters
Bo Jin1, Zai-Ran Wang1, Miao Yan1
1Department of Chemistry, Xinzhou Normal University, 1 East Dunqi Street, Xinzhou, Shanxi 034000, China.
Abstract:
Single-molecule nanorotors based on boron clusters often suffer from a trade-off between dynamic fluxionality and chemical stability. Herein, we extend our design strategy beyond the previously reported "ballet rotor" to its heavier group 7 congeners, technetium and rhenium. Through a comprehensive computational exploration, we identify the global minimum (GM) structures of MB10O10- (M = Tc, Re) as pyramidal clusters with the structural formula [(OB)3-M©B7O7]-, featuring a (BO)3 cap on one side of a B7O7 ring, resembling a three-bladed molecular propeller. Molecular dynamics simulations confirm the ultrafast, nearly barrierless rotation of the (BO)3 unit around the molecular axis. Remarkably, these fluxional clusters exhibit exceptional stability, with large HOMO-LUMO gaps (6.09-6.10 eV) and high vertical detachment energies (VDEs) (5.36-5.37 eV). Chemical bonding and nucleus-independent chemical shift (NICS) analyses reveal that the stability originates from a σ + π + δ triple aromaticity within the MB10 core, while the delocalized bonding also acts as a "lubricant" enabling free rotation. These triply aromatic molecular propellers represent a new, robust class of nanoscale rotors with promising potential for molecular machinery.
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