[2]Pseudorotaxane Composed of Heteroditopic Macrobicycle and Pyridine N‑Oxide Based Axle: Recognition Site Dependent Axle Orientation

A strategy for threading an axle having a hydrogen bond acceptor unit in the cavity of a C3v symmetric amido-amine macrobicycle is investigated. The macrobicycle acts as a wheel in its neutral as well as triprotonated states to form threaded architectures with a pyridine N-oxide derivative. The negative oxygen dipole of the axle is capable of [2]­pseudorotaxane formation in two different orientations with the wheel in its neutral and triprotonated states.