This analysis provided a characteristic timescale for such a "rare" bound-to-unbound transition in the order of ∼tens of seconds (see Fig. ), and an associated transition barrier of ∼ 18.5 ± 0.4 kcal mol -1 . Repeating such analysis starting from bound states B or C state and activating the transition to D does not change the results, providing very similar kinetics and, globally, transition timescales in the same order of magnitude. The transitions between the "bound" states (A, B and C) are in fact much faster than that of the boundto-unbound transition (Supplementary Movie 1). In fact, the latter requires the rupture of the HBs with benzimidazolium and is thus the rate-limiting step for the shuttling from one station to the other (for this reason, from this point on we refer simply to the "bound"