Two protocols for the preparation of [2]rotaxanes based on the dibenzo-24-crown-8-based cryptand/paraquat recognition motif

Host-guest complexation between a dibenzo-24-crown-8-based cryptand and a paraquat derivative was studied. Subsequently, two novel [2]rotaxanes based on the dibenzo-24-crown-8-based cryptand/paraquat recognition motif were prepared by threading-followed-by-stoppering method and single-pot method, respectively. The obtained mechanically interlocked structures were confirmed by 1H NMR, 13C NMR, 2D NMR, and ESI-MS.