Noncovalent Modification of Cycloparaphenylene by Catenane Formation Using an Active Metal Template Strategy**

Abstract

The active metal template (AMT) strategy is a powerful tool for the formation of mechanically interlocked molecules (MIMs) such as rotaxanes and catenanes, allowing the synthesis of a variety of MIMs, including π‐conjugated and multicomponent macrocycles. Cycloparaphenylene (CPP) is an emerging molecule characterized by its cyclic π‐conjugated structure and unique properties. Therefore, diverse modifications of CPPs are expected for its wide application. However, most CPP modifications require early‐stage functionalization and the direct modification of CPPs is very limited. Herein, we report the synthesis of a catenane consisting of [9]CPP and a 2,2´‐bipyridine macrocycle as a new CPP analogue that contains a reliable synthetic scaffold enabling diverse and concise post‐modification. Following the AMT strategy, [9]CPP–bipyridine catenane was successfully synthesized through Ni‐mediated aryl–aryl coupling. Catalytic C–H borylation/cross‐coupling and metal complexation at bipyridine macrocycle moiety, an effective post‐functionalization method, were also demonstrated with [9]CPP–bipyridine catenane. Single crystal X‐ray structural analysis revealed that the [9]CPP–bipyridine catenane forms a tridentated complex with an Ag ion inside the CPP ring. This interaction significantly enhances phosphorescence lifetime through improved intermolecular interactions.