Twin Triptycyl Spinning Tops: A Simple Case of Molecular Gearing with Dynamic C2 Symmetry

Abstract Lithiation and subsequent oxidation of the recently described prototype molecular paddlewheel 9‐(2‐indenyl)triptycene ( 1 ) leads to the racemic dimer 2,2′‐bis(9‐triptycyl)‐1,1′‐biindenyl ( 4 ). In the solid state this very congested molecule adopts a conformation in which the two triptycenyl paddlewheel fragments are attached to the C 2 ‐symmetric biindenyl core. However, the orientation of the triptycene blades, dictated by their …