Use of Anions To Allow Translational Isomerism of a [2]Rotaxane

We report a molecular [2]rotaxane which comprises a molecular cage and a dumbbell‐shaped component, in which translational isomerism can be performed reversibly through an in situ anion exchange process, that is, sequential addition of Bu4NCl/AgPF6 reagent pairs. The [2]rotaxane incorporates two pyridinium and two dialkylammonium centers and functions as a triply operable molecular switch, which can be controlled through altering the polarity of the solvent, adding acidic and basic reagents (TFA/Et3N), and the varying the nature of the counteranions (Cl− vs PF6−). A molecular [2]rotaxane, such as that depicted here, which comprises of a molecular cage and a dumbbell‐shaped component (the latter incorporating two pyridinium and two dialkylammonium centers) is reported. In the cavity of the rotaxane, translational isomerism can be performed reversibly through an in situ anion exchange process, that is, sequential addition of Bu4NCl/AgPF6 reagent pairs.