A switch in time: Gel–sol transitions of a urea-based [2]rotaxane gelator are controlled by the degree of solvent exposure of the hydrogen-bond-donating urea station and the orientation of the hydrogen-bond-accepting C[DOUBLE BOND]O groups of the interlocked ethylene glycol based macrocycle (N blue, O and macrocycle red, phenyl green). Both acid/base and anion-exchange control can be used to reversibly transition the rotaxane in 1-pentanol between solution and gel states.
關聯:
Angewandte Chemie International Edition 49(48), pp.9170-9173