Syntheses and stimuli-responsive rocking motions of a rotaxane bearing different stoppers

Abstract A rotaxane composed of a ring molecule having a metaphenylene unit, which swings as a pendulum, and a dianthrylethane unit, which undergoes isomerization in response to external stimuli, and an axle molecule with two different stopper units was synthesized. The rates of the rocking motion, which were switched reversibly, changed substantially by changing the size of the ring component in response to photo- and thermal-stimuli.