A biphenyl photosensitizer axle was implanted into the cavities of native and capped γ-cyclodextrins through rotaxanation using a cucubit[6]uril-templated azide-alkyne 1,3-dipolar cycloaddition, resulting in the construction of highly defined chiral binding/sensitizing sites. The orientation and interaction of the axle and capping moieties at the ground and excited states were interrogated by NMR, UV-vis, circular dichroism, and fluorescence spectroscopic studies. In situ photoisomerization of (Z,Z)-1,3-cyclooctadiene sensitized in the cavity of these [4]rotaxanes afforded (Z,E)-1,3-cyclooctadiene in up to 15.3% ee, which represents the highest level of enantiodifferentiation obtained to date for this supramolecular photochirogenesis.

The (P)- and (M)-3-azonia[6]helicenyl β-cyclodextrins exhibit L/D selectivities of up to 12.4 and P/M preferences of up to 28.2 upon complexation with underivatized proteinogenic amino acids in aqueous solution at pH 7.3.

The room temperature phosphorescence of iodine-substituted-γ-CD-CB[6]-cowheeled[4] rotaxanes was quenched specifically by tryptophan among plasma amino acids.

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Correction for ‘Room-temperature phosphorescent γ-cyclodextrin-cucurbit[6]uril-cowheeled [4]rotaxanes for specific sensing of tryptophan’ by Xingke Yu et al., Chem. Commun., 2019, 55, 3156–3159.