Acid-Activated Motion Switching of DB24C8 between Two Discrete Platinum(II) Metallacycles.

The precise operation of molecular motion for constructing complicated mechanically interlocked molecules has received considerable attention and is still an energetic field of supramolecular chemistry. Herein, we reported the construction of two tris[2]pseudorotaxanes metallacycles with acid-base controllable molecular motion through self-sorting strategy and host-guest interaction. Firstly, two hexagonal Pt(II) metallacycles and decorated with different host-guest recognition sites have been constructed via coordination-driven self-assembly strategy. The binding of metallacycles and with dibenzo-24-crown-8 (DB24C8) to form tris[2]pseudorotaxanes complexes and have been investigated. Furthermore, by taking advantage of the strong binding affinity between the protonated metallacycle and DB24C8, the addition of trifluoroacetic acid (TFA) as a stimulus successfully induces an acid-activated motion switching of DB24C8 between the discrete metallacycles and . This research not only affords a highly efficient way to construct stimuli-responsive smart supramolecular systems but also offers prospects for precisely control multicomponent cooperative motion.