Time-resolved X-ray Stark Spectroscopy to Quantify Charge-Transfer in Chemical Reactions and Catalysis

Catalysis with transition metals is driven by specific interactions between the metal and a molecule that ultimately enable the transformation of the latter. These interactions often involve the transfer of charge between the metal and the molecule.

It is this delicate back-and-forth charge-transfer via specific orbital interactions that constitutes the driving force of catalysis.

A robust quantification of the critical amount of charge-transfer, which is necessary to facilitate a molecular transformation, would thus enable a comprehensive understanding of what ultimately defines reactivity in catalysis. Such insight, however, is missing to date due to a lack of sensitive experimental probes.

In this project, I aim to fill this gap by developing a new type of spectroscopy capable of experimentally quantifying charge-transfer during catalytic reactions.

Time-resolved X-ray Stark spectroscopy combines the selectivity of time-resolved X-ray spectroscopy to specific elements, sites and orbitals of transient reaction intermediates with the quantitative sensitivity of Stark spectroscopy to molecular charge distributions.

By investigating the important class of C-H bond activation reactions, I will demonstrate the power of this new method and reveal the decisive mechanistic role of charge-transfer in catalysis with transition metals.