The ‘off’ state for aminocatalysis by a switchable rotaxane is shown to correspond to an ‘on’ state for anion-binding catalysis. Conversely, the aminocatalysis ‘on’ state of the dual-function rotaxane is inactive in anion-binding catalysis. Switching between the different states is achieved through the stimuli-induced change of position of the macrocycle on the rotaxane thread. The anion-binding catalysis results from a pair of triazolium groups that act together to CH-hydrogen bond to halide anions when the macrocycle is located on an alternative (ammonium) binding site, stabilizing the in situ generation of benzhydril cation and oxonium ion intermediates from activated alkyl halides. The aminocatalysis and anion-binding catalysis sites of the dual-function rotaxane catalyst can be sequentially concealed or revealed, enabling catalysis of both steps of a tandem reaction process.