Activation of Chalcogens by Uranium Centers - Reactivity Control via Ligand Architecture

• Applicant: Professor Dr. Karsten Meyer
• Subject Area: Inorganic Molecular Chemistry - Synthesis and Characterisation
• Term: from 2014 to 2019
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 259174626

During the last decades, the anhydrous chemistry of actinides was an active field of research. These research activities have mainly focused on the chemistry of uranium and thorium because their low radioactivity renders these ions suitable for use in practical application, ranging from fundamental coordination and organometallic chemistry to catalysis and material science. In this proposal, we envisage now the development of new tailor-made ligands, their coordination chemistry with low-, mid-, and high-valent uranium, and the application of these coordination complexes in reactivity studies towards chalcogen activation. In previous and published work of our groups we could show that our signature chelating ligands can act as very efficient supporting ligands in uranium-mediated reductive transformations, activation of elemental sulfur and selenium as well as heteroallenes, like carbon disulfide and carbonyl sulfide, could be observed. Based on these findings we propose in this joint research project to develop our existing ligand systems further in order to activate the elemental chalcogens for the synthesis of polychalcogenide-bridged complexes, which result from catenation to rings and chains of various sizes. These complexes will be studied by state-of-the-art spectroscopic and theoretical methods by the project partner. Further reactivity studies, including atom and group transfer reactions, removal of chalcogenides, activation of small molecules, redox and electrochemistry, etc., will provide further insight in the reactivity and electronic structures of the synthesized complexes. From a fundamental research point of view, complexes containing the hard uranium ion and soft sulfur, selenium, and tellurium ligands are fundamentally important to advance understanding of covalency in the metal ligand bond that is essential for the development of lanthanide/¬actinide separation methodologies or future, new catalytic systems.

• DFG Programme: Research Grants
• International Connection: France
• Participating Persons: Professor Dr. Laurent Maron; Professorin Dr. Marinella Mazzanti