Applications of macrocycle-based solid-state host–guest chemistry

Macrocyclic molecules have been used in various fields owing to their guest binding properties. Macrocycle-based host–guest chemistry in solution can allow for precise control of complex formation. Although solution-phase host–guest complexes are easily prepared, their limited stability and processability prevent widespread application. Extending host–guest chemistry from solution to the solid state results in complexes that are generally more robust, enabling easier processing and broadened applications. Macrocyclic compounds in the solid state can encapsulate guests with larger affinities than their soluble counterparts. This is crucial for use in applications such as separation science and devices. In this Review, we summarize recent progress in macrocycle-based solid-state host–guest chemistry and discuss the basic physical chemistry of these complexes. Representative macrocycles and their solid-state complexes are explored, as well as potential applications. Finally, perspectives and challenges are discussed.