Molecular Spur Gears with Triptycene Rotators and a Norbornane-Based Stator.

We report efforts to prepare a molecular spur gear utilizing a convenient synthesis of a norbornane stator that positions two interdigitated diyne-linked triptycenes in parallel alignment. While gearing was not observed by 19F NMR for a -CF3-labeled analog at temperatures as low as 213 K, we used molecular dynamics simulation and 2D metadynamics calculations to understand the gearing/slippage energetic profile for various molecular spur gears to guide future designs of these systems.