Metallocavitands: an emerging class of functional multimetallic host molecules.

The study of traditional organic cavitands has been central in the development of supramolecular chemistry. As the field of supramolecular chemistry matures, a new class of cavitand, the metallocavitand, is quietly emerging. No central theme currently exists to unify these relatable supramolecules due to the structural diversity of metallocavitands. To provide a concrete foundation for future metallocavitand research, we define metallocavitands here as multimetallic complexes where metal coordination is necessary for cavity formation. This tutorial review highlights synthetic routes based on self-assembly and macrocycle-templating strategies to isolate bowl-shaped metallocavitands, and highlights interesting supramolecular phenomena observed with metallocavitands such as dimerization, host-guest encapsulation, catalysis, unique regioselective reactivity, and enantioselective guest recognition.