The Applications of Metallacycles and Metallacages

Metallacycles and metallacages constitute a class of coordination compounds composed of metal ions and organic ligands. Because of their precise stoichiometry, the flexibility and viability of design, metallacycles and metallacages have attracted considerable attention as supramolecular assemblies. Various two-dimensional polygons, three-dimensional polyhedra, and other nanoscale materials have been constructed and applied. The highly diverse structures, sizes, and shapes endow metallacycles and metallacages with unique physical and chemical properties and make them suitable for various applications such as encapsulation, separation, catalysis, and biological science. Herein, we review the recent developments in various metallacycles and metallacages in different fields. The text highlights biomedical applications involving molecular recognition and binding, antibacterial activity, and especially cancer diagnosis and treatment, including imaging, chemotherapy, PDT, and PTT.