Metallosupramolecular assemblies and metal-organic frameworks

Nanometre-sized polyhedral or prismatic chemical architectures can self-assemble from combinations of transition metal cations and multifunctional ligands. Likewise supramolecular materials such as coordination polymers or metal-organic frameworks (MOFs) may be formed. These assemblies are often hollow or porous and provide a confined chemical space where other molecules can be bound.

Hence many of these systems are being developed as nano-scale vessels or crystalline sponges for chemical entrapment, signalling and sensors, and even as tiny reaction vessels. We use the host molecule cyclotriveratrylene (CTV) as a scaffold as its relatively rigid pyramidal shape lends itself to the formation of cage-like or porous species, and analogues with three or six metal-binding groups can be made. These can form discrete metallo-cages, MOFs or other network materials including unique chemical topologies such as a Borromean chain-mail.

Different potential projects in this area include (i) functional metallo-cages for applications such as molecular recognition, chemical sensors or catalysis; (ii) trinuclear complexes of host ligands with luminescent or catalytic properties; (iii) stimuli-responsive metallo- and organic cages which can change shape or composition with a physical or chemical trigger. All projects include multi-step organic synthesis of ligands, synthetic coordination and supramolecular chemistry, solution characterisation of assemblies and host-guest and other properties using spectroscopic techniques, single crystal X-ray crystallography, and more.