Low-valent Molybdenum Chemistry

Molybdenum plays a central role in a wide number of enzymatic systems involved in small molecule conversion, notably within the FeMo cofactor of nitrogenase but also in nitrate reductase, FDH and CODH. Knowledge of the chemical and reactivity properties of six-coordinate Mo complexes is hence key to a better understanding of these enzymatic systems. Most of them operate in the higher oxidation states of Mo, and the coordination chemistry as well as corresponding reactivities of these high oxidation states have been extensively studied and applied for the design of bioinspired Mo-based complexes.

However, the chemistry of six-coordinate low-valent Mo complexes has been comparably underexplored despite promising activities in CO2 reduction, being essentially limited to complexes are supported by neutral, strongly 𝜋-accepting donor ligands such as CO, NO or phosphines, with only a handful of mononuclear six-coordinate Mo(IV) and Mo(III) compounds bearing oxygen or sulfur donating anionic ligands reported in literature. We are currently exploring and developing the coordination chemistry and reactivity of low valent β-diketonate Mo complexes as a platform to for the design of new catalysts and the improved understanding of their fundamental properties.