Seeing clear where others can’t – X-rays uncover the birth of C-H activation catalysts and how they function

Project title: Seeing clear where others can’t – X-rays uncover the birth of C-H activation catalysts and how they function
Main applicant: Philippe Wernet, Division of X-ray Photon Science
Grant amount: SEK 4 100 000 for the period 2025-2028

C-H bond activation, or the breaking of carbon-hydrogen bonds, is the essential first step in the transformation of C-H bonds into chemical groups with targeted function. Activating C-H bonds, however, requires catalysts as the bonds are strong, non-polar and inert. Photochemical C-H activation with metal-hydride complexes has been discovered decades ago but controlling their catalysis has been difficult because mechanistic understanding has been scarce due to a lack of suitable probes. The aim of this proposal is to use time-resolved X-ray spectroscopy to uncover hitherto inaccessible information on the mechanisms of photochemical C-H activation with homogeneous metal-hydride catalysts. With metal-specific X-ray spectroscopy we will follow in real time of the reactions how the catalyst becomes reactive and how it cleaves C-H bonds in hydrocarbons from solution. Postdocs will work on this project with me, my group, and my theory collaborators over a time period of four years. Addressing the metal-specific electronic structure as a function of time is a new way of determining reactivity at the ultimate quantum-mechanical level of orbital interactions. This informs strategies for chemical synthesis and theoretical predictions for new C-H activation catalysts. Ensuing solutions for the production of high-value chemicals help building the foundations for circular carbon economies, balanced carbon cycles in materials production, new routes to polymerization and pharmaceuticals.