New Molecule-Based Magnetic Materials constructed from Paramagnetic Ruthenium and Osmium Building Blocks

Magnets are important materials with a variety of applications. In the last three decades, the design of molecule-based magnetic materials has become an important multidisciplinary research area. In general these materials are clusters or polymers made by joining paramagnetic transition metal centers with various inorganic and/or organic bridging groups. Compared to traditional magnetic materials, molecule-based magnetic materials may have many advantageous features such as transparency, solubility, flexibility, low density, biocompactibility, ease of fabrication at lower temperatures, magneto-optic response and redox activity. The properties of these materials can be readily tuned by systematic variations of the metal centers and the bridging groups. The majority of molecule-based magnetic materials are based on first-row transition metals, and much less is known about the structures and properties of those containing second and third-row transition metals. Since 4d and 5d orbitals are more diffuse than 3d orbitals, stronger magnetic exchange interactions between metal centers may be expected. In the researhcers' previous NSFC/RGC project (20318001/CityU107/03, 2003-2006), they have synthesized a number of magnetic materials based on paramagnetic ruthenium(III) building blocks, which exhibit a variety of magnetic properties. Our results suggest that ruthenium is a promising metal center for the construction of novel magnetic materials. This project is a continuation of our previous NSFC/RGC project. The researchers plan design a variety of new paramagnetic ruthenium and osmium building blocks. These new building blocks will be used to construct novel magnetic materials. Particular emphasis will be placed on osmium systems, since as far as we are aware, no magnetic materials based on osmium has been reported. Their studies should contribute to the development of new magnetic materials based on ruthenium and osmium.