HurdlingOxoWall · Late First-Row Transition Metal-Oxo Complexes for C–H Bond Activation

The chemical, pharmaceutical, and materials industries rely heavily upon chemicals from oil and natural gas feed-stocks (saturated hydrocarbons) that require considerable functionalisation prior to use. Catalytic oxidative functionalisation (e.g. CH4 + [O] + cat. → CH3OH), using first row transition metal catalysts, is potentially a sustainable, cheap, and green route to these high-commodity chemicals. However, catalytic oxidation remains a great modern challenge because such hydrocarbons contain remarkably strong inert C–H bonds that can only be activated with potent catalysts. We will take a Nature-inspired approach to designing and preparing powerful oxidation catalysts: we will interrogate the active oxidant, a metal-oxo (M=O) species, to guide our catalyst design. Specifically, we will prepare unprecedented Late first-row transition Metal-Oxo complexes (LM=O’s, LM = Co, Ni, Cu) that will activate the strongest of C–H bonds (e.g. CH4). This will be accomplished using a family of novel low coordinate ligands that will support LM=O’s. Due to their expected potent reactivity we will prepare LM=O’s under unique oxidatively robust, low-temperature conditions to ensure their stabilisation. The poorly understood factors (thermodynamics, metal, d-electron count) that control the reactivity of M=O’s will be thoroughly investigated. Based on these investigations LM=O reactivity will be manipulated and optimised. We expect LM=O’s will be significantly more reactive than any early transition metal-oxo’s (EM=O’s), because they will display a greater thermodynamic driving force for C–H activation. It is thus expected that LM=O’s will be capable of the activation of the strongest of C–H bonds (i.e. CH4). Driven by the knowledge acquired from these investigations, we will design and prepare the next generation of molecular oxidation catalysts - a family of late first-row transition metal compounds capable of catalysing hydrocarbon functionalisation under ambient conditions.