A series of interlocked anion-π catalysts have been prepared that combine a π-acidic NDI unit in the axle component with a basic site provided by a bipyridine-triazole cavity. These catalysts were found to be highly selective in an established benchmarking reaction for anion-π catalysis, with a dependence of catalyst activity and selectivity on the length of azide half-axle used in the AT-CuAAC synthesis. The selectivity obtained with readily accessible [3]rotaxane catalyst 13 is comparable to the most effective example previously reported. Control experiments demonstrated the importance of the interlocked structure and the NDI unit to catalyst selectivity. Computational studies strongly suggest that the high selectivities observed, particularly for 13, is due to π-stacking between the protonated bipyridine unit and the NDI surface which results in a highly polarisable, π-acidic surface that can efficiently stabilise the planar enolate, which is corroborated by solid state structures of a [2]rotaxane catalyst in both neutral and protonated forms. In addition to the ability of the mechanical bond to place all the required units in the required arrangement with minimal synthetic effort, the solubility of the rotaxane catalysts, which can be an issue in the case of NDI-based molecules, makes this scaffold particularly attractive.