A pH Switchable Pseudorotaxane Based on a Metal Cage and a Bis-anionic Thread



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Please let me in! A new kind of (pseudo)rotaxane is formed quantitatively when a bis-anionic thread is added to a molecular cage comprised of two positively charged metal complexes. The rotaxanation mechanism follows two alternative ways depending on the metal (Pd vs. Pt) and the stopper size of the guest (see figure).