Pillar-Shaped Macrocyclic Hosts Pillarnarenes: New Key Players for Supramolecular Chemistry

In 2008, we reported a new class of pillar-shaped macrocyclic hosts, known as "pillarnarenes". Today, pillarnarenes are recognized as key players in supramolecular chemistry because of their facile synthesis, unique pillar shape, versatile functionality, interesting host-guest properties, and original supramolecular assembly characteristics, which have resulted in numerous electrochemical and biomedical material applications. In this Review, we have provided historical background to macrocyclic chemistry, followed by a detailed discussion of the fundamental properties of pillarnarenes, including their synthesis, structure, and host-guest properties. Furthermore, we have discussed the applications of pillarnarenes to materials science, as well as their applications in supramolecular chemistry, in terms of their fundamental properties. Finally, we have described the future perspectives of pillarnarene chemistry. We hope that this Review will provide a useful reference for researchers working in the field and inspire discoveries concerning pillarnarene chemistry.