Angewandte Chemie | 2021
Chemoresponsive Supramolecular Polypseudorotaxanes with Infinite Switching Capability.
Abstract
Chemoresponsive supramolecular systems with infinite switching capability are important for applications in recycled materials and intelligent devices. To attain this objective, here a chemoresponsive polypseudorotaxane is reported on the basis of a bis( p -phenylene)-34-crown-10 macrocycle ( H ) and a cyano-substituted viologen guest ( G ). H and G form a [2]pseudorotaxane ( H ⊃ G ) both in solution and in the solid state. Upon addition of AgSF 6 , a polypseudorotaxane (denoted as [ H·G· Ag] n ) forms as synergistically driven by host-guest complexation and metal-coordination interactions. [ H·G· Ag] n depolymerizes into a [3]pseudorotaxane (denoted as H 2 ·G· Ag 2 · acetone 2 ) upon addition of H and AgSF 6 , while it reforms with successive addition of G . The transformations between [ H·G· Ag] n and H 2 ·G· Ag 2 · acetone 2 can be switched for infinite cycles, superior to the conventional chemoresponsive supramolecular polymeric systems with limited switching capability. Therefore, by taking advantage of the adaptive macrocycle/guest complexation characters, the current study opens up new avenues toward precision engineering of chemoresponsive supramolecular polymers.