Toward Chemically Controlled Nanoscale Molecular Machinery

Mechanical displacement of the ring by around 40 % along the approximately 9‐nm long dumbbell‐shaped component has been seen in a bistable redox‐controllable [2]rotaxane. Chemical oxidation of the tetrathiafulvalene recognition station (green, see scheme) in the dumbbell‐shaped component, which also contains a 1,5‐dioxynaphthalene recognition station (red), results in the cyclobis(paraquat‐p‐phenylene) tetracation (blue) undergoing translation from the much preferred green station to the second‐choice, red station.