Beyond the Metallacrown: Controlling First- and Second-Order Coordination Spheres Towards Discrete and Extended Architectures

The global aim of this review chapter is to highlight how synthetic chemists are able to manipulate pre-selected metallacrowns at both their first and second-order coordination spheres towards the production of novel discrete host–guest complexes. We will begin by discussing how the flexible functionality afforded to metallacrowns allows a degree of control with respect to their second-order coordination spheres and strongly encourages complementary interactions with target substrates towards the production of discrete host–guest complexes. We will show how these findings have led to a plethora of interesting new materials with applications in (for example) molecular sensing, molecular magnetism and quantum computing. We will also discuss the strategic first-order coordination sphere modulation of select 12-MCCu(II)-4 metallacrowns towards the construction of pre-determined extended architectures.