To take further advantage of all of these effects while increasing the impact of -stacking on catalyst activity, we synthesised [3]rotaxane 13 using the AT-CuAAC reaction 24 of a simple bis-propargyl NDI in excellent yield (ESI section S2.1). Molecular modelling indicates that 13 is structurally similar to rotaxane 4b in that in the neutral structure it is folded such that both bipyridines stack with the NDI unit (Figure ). Either single or double protonation, to give 13H + or 13H2 + respectively, is predicted to result in a folded structure in which one neutral and one protonated, or two protonated bipyridines stack with the NDI core respectively (Figure ). Importantly, in both cases the NDI is blocked such that it is unavailable to interact with enolate 9, suggesting that any anion- catalysis that arises in the case of 13 would take place through interaction of 9 with the bipyridium unit.