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 two families of molecular compounds that can display functionality: single-molecule magnets (SMMs) and valence tautomeric (VT) complexes. We are particularly interested in the synthesis of polynuclear complexes of d-block transition metals or lanthanoids 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 colleague Dr Alessandro Soncini and some of our polyoxometalate-based research is performed in collaboration with Dr Chris Ritchie. 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 magnetic measurements on the synthesised materials in collaboration with Prof Keith Murray (Monash University) and photomagnetic and EPR studies in collaboration with Dr Lorenzo Sorace (University of Florence, Italy), X-ray absorption studies with Dr Hugh Harris (University of Adelaide), inelastic neutron scatteing studies with Dr Richard Mole, photophysical measurements with Dr Evan Moore (University of Queensland) and Prof Christian Reber (University of Montreal) and electrochemical studies in collaboration with Prof Alan Bond and Dr Jie Zhang (Monash University). New collaborations for DFT calculations with Prof Rob Stranger (Australian National University) and Dr Xavi Lopez and Prof Josep Poblet (Universitat Rovira i Virgili, Spain) are providing invaluable insights into the electronic structure of our VT complexes and POMs.