Supramolecular gelator based on a [ c 2]daisy chain rotaxane: efficient gel-solution transition by ring-sliding motion

A supramolecular gelator based on the bistable [ c 2]daisy chain rotaxane is designed and synthesized. The reversible actuation of the [ c 2]daisy chain renders the formed supramolecular gel with acid/base-responsive switching between gel and monomer solution. The efficient switching process is attributed to the ring-sliding effect of the rotaxane in response to acid/base stimuli. The ring-inhibited hydrogen bonding stacking results in a nearly quantitatively disassembly of the gel network after addition of base which is hard to be realized by traditional heating strategy in hydrogen-bonding-supported gel.