CHAPTER 4: Self-assembled Chiral Metallomacrocycles

Chiral supramolecular systems have been extensively studied over the past two decades because of their ability to mimic complex biological processes and their potential applications in enantioselective recognition, sensing, and catalysis. Chiral metallomacrocycles, as one of the simplest forms of chiral supramolecular systems, are of particular interest because of their relative ease of synthesis. In this chapter, we survey recent developments in the rational design and construction of chiral metallomacrocycles based on metal-ligand coordination and their applications. Based on the source of chirality, chiral metallomacrocycles can be broadly categorized into three synthetic strategies: (1) introduction of chiral bridging ligands, (2) use of chiral metal auxiliaries that possess chiral capping groups, and (3) use of inherently chiral metal centres having specific coordination geometries. The synthetic utility of these three strategies is illustrated in this chapter by some examples of chiral metallomacrocycles with diverse sizes and functionalities. A number of interesting applications, ranging from chiral sensing to asymmetric catalysis, are also described.