Chapter 10. Functional Metallo-supramolecular Polyhedral Capsules and Cages

Metallo-supramolecular capsules and cages epitomise the elegant manner in which self-assembled functional materials can be designed from first principles. Not only are these materials inherently beautiful, they are useful, performing myriad functions within the spaces that they enclose. Metallo-supramolecular capsules and cages can be prepared to be charged or neutral, large or small, open or closed and often display interesting properties including notable spectrochemical, electrochemical and magnetic effects in their own right. Through encapsulation, metallo-supramolecular capsules and cages have been demonstrated to be useful agents for host–guest chemistry, binding a wide variety of guests such as anions, cations or neutral molecules (including gases) and have been shown to catalyse a number of reactions producing unusual products more efficiently. In this chapter, after briefly discussing the design of these materials and the process of encapsulation, we survey the functions performed by metallo-supramolecular capsules and cages including selective guest binding, separations of molecular mixtures, sequestration of greenhouse gases and their use as modulators of chemical reactivity.