Two bis(p-phenylene)-34-crown-10-based cryptand constitutional isomers: different binding abilities induced by structural alterations

Two novel bis(p-phenylene)-34-crown-10-based cryptand constitutional isomers were prepared and their host–guest complexations with paraquat were studied by ESI-MS, UV–vis spectroscopy, 1H NMR spectra, and X-ray crystal structures. Notably, though the only difference between the two hosts is the location of the nitrogen atom on the third arms, they exhibited quite different binding abilities with paraquat. Competitive complexation was carried out and it may provide a simple way to construct sophisticated supramolecular materials with reversibility and adaptability.