Exploiting the mechanical bond for molecular recognition and sensing of charged species

The unique properties of the mechanical bond have been increasingly used for the purpose of molecular recognition. The recent progress in the development of cation and anion template strategies for the construction of mechanically interlocked molecules (MIMs) have resulted in a variety of ion binding catenane and rotaxane host structures. The appropriate integration of reporting redox- and photo-active centres into their structural frameworks can result in prototype molecular sensors for targeting charged species and molecular switches for potential nanotechnological applications. This review presents progress in the field of MIM hosts for ion recognition and sensing since 2014, focusing on the synthetic approaches employed and mechanisms of host-guest binding and detection.