Research objectives and content
The synthesis of bridged multinuclear paramagnetic complexes is of particular current interest in view of the construction of useful magnetic materials. Objectives of the work are syntheses of new binuclear complexes in which two paramagnetic transition metal fragments are linked by a spacer, which contains a fluorenone subunit. Studies on these systems especially by electrochemical methods and by EPR-spectroscopy will provide information regarding intramolecular interactions of subunits within a multicomponent system. The incorporation of fluorenone in comlexes is attractive due to its fully conjugated aromatic 3,14-system, which enables extensive intermetal communication, and due to the property of forming a stable, monoradical anion offering the possibility of reversibly creating additional paramagnetic centers. Reduction of the fluorenone units could give rise to radical species trapped between paramagnetic metal centers. This is until now totally unexplored with unprecedented possibilities for studying paramagnetic metal-radical interactions. Since the redox state of the fluorenone is expected to control the magnetic metal-metal interaction, it can be regarded as a molecular magnetic switch which could be of high interest for technical devices. The studies on these systems will also provide information in view of the pathway of spin-spin exchange processes and of the effects responsible for anti- or ferromagnetic coupling between unpaired spins.
Training content (objective, benefit and expected impact)
Fluorenone as bridging ligand between two suitable paramagnetic 17-VE transition metal fragments should give access to molecular magnetic switches, e.g. systems where the magnetic metal interactions can be controlled by the redox state of the fluorenone. Such a behaviour is of high interest in regard to the creation of new high spin ferromagnetic systems useful for technical devices and for the development of material which can be reversibly converted from an insulator to a conductor. My scientific work for this proposal will allow me to expand my knowledge in the area of organometallic- and metal-mediated syntheses, electrochemistry and spectroscopy. I will learn new instrumental techniques such as square wave voltammetry and differential pulse techniques, and through collaborations acquire training in the determination of magnetochemical properties of compounds. I also expect training in theoretical chemistry regarding EPR-simulations and molecular modelling.
Links with industry / industrial relevance (22)
The group of Prof. McCleverty has an industrial collaboration with Sharpe Electronic Industries.