This thesis concerns the design of metallosupramolecular architectures incorporating a specific function, namely light-responsive properties, for potential applications in molecular recognition, molecular electronics and as stimuli-responsive materials. This is achieved by employing established geometrically directing metallotectons in combination with novel light-responsive tripodal hosts based on the cyclotriveratrylene scaffold.
A novel library of light-responsive molecular hosts have been prepared via novel asymmetrical azobenzene precursors. These light-responsive ligands undergo self-assembly with a variety of Ir(III) metallotectons to give a family of M3L2 metallocryptophanes, thus implanting the light-responsive functionality into these systems. Solution-state analysis indicates these metallocages contain a significant internal space for potential applications in molecular recognition.
The photoresponsive properties of both the novel ligands and metallocryptophanes has been explored utilising light of UV and visible wavelengths to toggle between the
trans/cis conformations of the embedded azobenzene units, resulting in dramatic structural perturbations in solution, pointing the way to sophisticated applications in molecular recognition. Photophysical analysis of these metallocryptophanes reveals deep blue emission properties, characteristically uncommon for Ir(III) complexes.
A series of non-discrete coordination polymers have also been prepared and crystallographically elucidated from the combination of a light-responsive ligand with various Cu(II) and Ag(I) salts. Although light-responsive behaviour is yet to be demonstrated in these systems, a solvent-induced structural rearrangement is observed
in one example, potentially promising further sophisticated host-guest properties.
