An Acid-Base-Controllable [c2]Daisy Chain

摘要

Artificial molecular-based muscles, which can convert chemical, electrochemical, or photochemical energy into mechanical motion, have attracted attention as a result of their potential for spawning nanoelectromechanical systems (NEMS). Several materials, such as conducting polymers, single-walled carbon nanotubes, and dielectric elastomers, have been developed which exhibit muscle-like behavior at the nanoscale level. However, all these systems rely upon the response of a bulk substance, rather than on the behavior of individual molecules. Recently, artificial muscles have been designed on a molecular scale by taking advantage of conformational changes exerted by electrochemical stimuli. For example, oligothiophene-calix[4]arene copolymers and thiophene-fused annulenes exhibit molecular actuating behavior under redox control while crown-ether-annelated oligothiophenes and polyheterocyclic strands have ion-triggered muscle-like properties. Nanoscale molecular motions, based on artificial molecular machines, offer alternative opportunities to design artificial muscle-like materials.