Stimuli-responsive mechanically interlocked molecules constructed from cucurbit[ n ]uril homologues and derivatives.

Cucurbit[ n ]uril supramolecular chemistry has developed rapidly since 2001 when different cucurbit[ n ]uril homologues (Q[ n ]) were successfully separated in pure form. The combination of Q[ n ] cavity size and various types of external stimuli has given birth to numerous types of Q[ n ]-based mechanically interlocked molecules (MIMs), including (pseudo)rotaxanes, catenanes, dendrimers and poly(pseudo)rotaxanes. In this review article, the important advances in the field of Q[ n ]-based MIMs over the past two decades are highlighted. This review also describes examples of heterowheel (pseudo)rotaxanes and poly(pseudo)rotaxanes involving Q[ n ]s, and reflects on the opportunities and challenges of constructing Q[ n ]-based stimuli-responsive MIMs.