Photoactive supramolecular cages incorporating Ru(II) and Ir(III) metal complexes

The self-assembly of arrays of metal ions with bridging ligands has evolved during the last twenty years as a powerful approach for the construction of cages and capsules with well-defined shapes and cavities. There has been of late an increasing exploration of photoactive supramolecular cages in which at least one component, either the metal ion or the ligands, themselves incorporating metal complexes (metalloligands), are phosphorescent. Desirable photophysical properties such as emission tuning and encapsulation-assisted energy and electron transfer have been achieved by integrating phosphorescent d-block Ir(III) and Ru(II) complexes into the backbone of metallosupramolecular cages and capsules. Such cages have been used in sensing applications, photocatalysis and in the context of solar fuels production. This feature article summarises the recent work on cage assemblies containing Ir(III) and Ru(II) metal complexes as photoactive units, highlighting our contribution to this growing field and bringing together our key results.