Exploiting the Mechanical Bond Effect for Enhanced Molecular Recognition and Sensing

• Published in: Advanced materials (Weinheim) 2024-04, Vol.36 (14), p.e2309098-n/a
• Main Authors: Wilmore, Jamie T., Beer, Paul D.
• Format: Article
• Language: English
• Subjects: Affinity; Binding; Biological activity; catenane; Chemical bonds; mechanical bonding; Recognition; rotaxane; sensing; supramolecular; Topology
• ISSN: 0935-9648; 1521-4095
• DOI: 10.1002/adma.202309098

The ubiquity of charged species in biological and industrial processes has resulted in ever‐increasing interest in their selective recognition, detection, and environmental remediation. Building on the established coordination chemistry principles of the chelate and macrocyclic effects, and host preorganization, supramolecular chemists seek to construct specific 3D binding cavities reminiscent of biotic systems to enhance host‐guest binding affinity and selectivity. Mechanically interlocked molecules (MIMs) present a wholly unique platform for synthetic host design, wherein topologies afforded by the mechanical bond enable the decoration of 3D cavities for non‐covalent interactions with a range of target guest geometries. Notably, MIM host systems exhibit mechanical bond effect augmented affinities and selectivities for a variety of charged guest species, compared to non‐interlocked acyclic and macrocycle host analogs. Furthermore, the modular nature of MIM synthesis facilitates incorporation of optical and electrochemical reporter groups, enabling fabrication of highly sensitive and specific molecular sensors. This review discusses the development of recognition and sensing MIMs, from the first reports in the late 20th century through to the present day, delineating how their topologically preorganized and dynamic host cavities enhance charged guest recognition and sensing, demonstrating the mechanical bond effect as a potent tool in future chemosensing materials. Building upon the established chelate and macrocyclic effects, supramolecular chemists have exploited the mechanical bond to create selective supramolecular hosts with enhanced binding affinities and selectivity over non‐interlocked acyclic and macrocyclic host analogs. This review delineates advantages of mechanically interlocked hosts for charged species, and discusses current and potential applications of the mechanical bond effect for recognition and sensing applications.