Muscle-Like Supramolecular Polymers with Dual Motion Patterns.

Benefiting from the features like polymeric linear structures, stimuli-responsiveness and dynamic adaptiveness, supramolecular polymers (SPs) are favored as exploiting muscle-like materials, allowing for imitating the muscle functions. However, a substantial part of these materials barely owned an unitary motion orientation while it was obviously known that muscle movements involved distinct orientations. Herein, M1 holding the structure of 44-membered macrocycle with two aldehyde groups was designed, meanwhile, M2 comprising of secondary ammonium ions, 3,5-di-tert-butylphenyl groups as well as the alkyl chains was fabricated, for which it could be assembled with M1 to generate SPs based on host-guest interactions from a large macrocycle and two secondary ammonium ions. SPs underwent vertical compression upon the addition of N2 H4 owing to the forming dynamic covalent bonds, notably, mechanically interlocked structures were also generated. Afterwards, the vertically compressed SPs experienced horizontal shrinkage when tetrabutylammonium chloride was contributed due to the destruction of host-guest interactions.