Making the second generation of molecular motors operate unidirectionally in response to electricity

Abstract

Electricity is an attractive energy input to operate molecular motors. We found that anionization using constant potential could make the 2nd generation molecular motors operate under ground state unidirectionally, persistently, and free from ultraviolet light. In this approach, the original energetically uphill step with large energy barrier driven by ultraviolet could be replaced by a combination of an anionization step followed by an energetically downhill anionic isomerization and a neutralization step. Anionization decreases the energy barrier of the first isomerization step significantly, while the barrier of the second isomerization step still keeps high level, which ensures nearly 100% perfect unidirectionality kinetically. The free energy of the anionic intermediate isomer is lower enough than that of the original isomer, which makes the isomerization could be driven thermodynamically and ensures the nearly 100% perfect unidirectionality. We hope that our investigations could provide a new strategy for constructing electronic stimuli-responsive nanosystems based on the 2nd generation molecular motors.