Molecular materials with physical properties that can be controlled by external parameters, such as temperature, light or magnetic field are important synthetic targets because they form the basis of molecular devices. The miniaturisation required by technological advances in electronics makes the demand for such nanoscale devices inevitable. For instance, switchable molecules can be reversibly interconverted between two different states by an external stimulus, sometimes with hysteresis accompanying the interconversion. Inorganic molecular materials based on switchable molecules have potential applications in high density data storage, quantum computing, molecular electronics or display devices
Research in our group is focused on the exploration of different families of inorganic molecules that can display functionality arising from their electronic structure: single-molecule magnets (SMMs), valence tautomerism (VT) and spin crossover (SCO) complexes. We are particularly interested in polynuclear complexes of d-block transition metals or lanthanoids (rare earths) that can act in either of these capacities. These complexes incorporate organic N- and O-donor ligands and/or inorganic polyoxometalate (POM) ligands to bridge and chelate the paramagnetic metal centres. The VT complexes in particular require redox-activity in both the ligands and metal centres and are typically thermochromic. The lanthanoid-polyoxometalate complexes are also of interest for their luminescence and photochromic properties.
Theoretical modelling of our lanthanoid-polyoxometalate complexes is carried out in collaboration with colleagues Dr Lars Goerigk and Dr Alessandro Soncini. The detailed physical characterisation of the synthesised species affords an understanding of the key electronic and magnetic properties and allows correlation with the molecular structure. To this end, we perform Mössbauer spectroscopy on the synthesised materials in collaboration with A/Prof Guy Jameson, magnetic, photomagnetic and EPR measurements in collaboration with Prof Lorenzo Sorace (University of Florence, Italy) and Dr Rodolpe Clérac (CRPP-CNRS, Bordeaux, France), inelastic neutron scattering studies with Dr Richard Mole (ANSTO), and photophysical measurements with A/Prof Max Massi (Curtin University). A new collaboration for DFT calculations with Dr Alyona Starikova (Southern Federal University, Russia) is providing invaluable insights into the electronic structure of our VT complexes. We are also working on coordination polymers in collaboration with Dr Carol Hua. Colette is an Associate Investigator in the ARC Centre of Excellence for Exciton Science.