Transition metal hydride and main-group element complexes in new ligand environments

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Transition metal hydrides, compounds with a metal-hydrogen bond, are indispensable in chemistry due to their relevance to the whole range of catalytic industrial hydride transfer processes, including the production of both commodity chemicals and fine chemicals, and in laboratory applications to make a large range of derivatives. Whereas industrial catalysts are primarily heterogeneous with a poorly defined nature of reactive intermediates, laboratory homogeneous catalysts feature very well-defined reactive sites (usually based on one, two or few metal centres) supported by ancillary groups of controllable electronic and steric properties. Until very recently, the vast majority of established hydride complexes were based solely on the abundant phosphine, carbonyl, and polyolefin ligand environments, while relatively little is known about the reactivity of hydride complexes supported by new generations of nitrogen-based ligands. Such new ligands and ligand combinations are now well established, but almost exclusively in the narrow context of homogeneous olefin polymerization catalysis.Another significant venue of research in hydride chemistry is focused on understanding the nature of bond rupture/formation processes in the coordination sphere of metals during catalysis. To this end, the isolation and study of complexes with "frozen" interligand interactions is extremely important. The hydride compounds were the domain in which the phenomenon of nonclassical interligand bonding was discovered, first, in dihydrogen complexes and in CH-agostic complexes and, second, in other sigma-complexes. This allowed scientists, for the first time, to model the key steps in the metal-mediated transformations of small molecules. In particular, our group pioneered the investigations of interligand hypervalent interactions and discovered new families of complexes featuring stretched beta-Si-H agostic interactions.The fundamental aim of this project is to prepare and study new types of potentially catalytically active transition metal hydride complexes and understand their activity through the study of complexes with "frozen" nonclassical interligand interactions.