Construction of anion-responsive crosslinked polypseudorotaxane based on molecular recognition of pillar[5]arene

A pillar[5]arene pendant polymer (Poly-P[5]A) is synthesized via ROMP using Grubb's first-generation catalyst. GPC analysis of the polymer suggested similar to 30 pendant pillar[5]arene units in the polymer. Supramolecular polypseudorotaxane assembly is constructed by intermolecularly crosslinking pendant pillar[5]arene units using a bispyridinium guest via host-guest complexation. Formation of the polypseudorotaxane assembly is characterized by 1D/2D NMR techniques and DLS analysis. Moreover, anion-responsiveness of the polypseudorotaxane assembly is demonstrated by H-1 NMR spectroscopic analysis using chloride anion as external stimulus. Scanning electron microscopic analysis of the poly-P[5]A showed breath-figure assembly and upon crosslinking with G.2PF(6) the polymer self-assemble to give a supramolecular polymer network. (c) 2019 Wiley Periodicals, Inc.