PH-responsive movement of cucurbit[7]uril in a diblock polypseudorotaxane containing dimethyl β-cyclodextrin and cucurbit[7]uril

A polypseudorotaxane consisting of cucurbit[7]uril (CB[7])/N,N'-(3-phenylenebis(methylene) dipropargylamine (PMPA), [2] pseudorotaxane, and 2,6-O-dimethyl, beta-cyclodextrin (DM-beta-CD)/alpha,omega-bisazidopropylene glycol 400 [2]pseudorotaxane was synthesized using the click reaction. The polypseudorotaxane structure was maintained in aqueous solution over a wide range of pH values with the DM-beta-CD units contributing to increased solubilization of the polypseudorotaxane without dethreading. The pH-responsive movement of the CB[7] units in the polypseudorotaxane was also observed.