(Invited) Atomic View of Nickle Dithiolene Electro- and Photo-Catalysis Using X-Ray Absorption Spectroscopy

Abstract

Metal dithiolenes are a class of molecular catalysts known for their redox-active ligands and their efficient and robust electro- and photo-catalysis of the hydrogen evolution reaction. To understand how the redox-active ligands of these catalysts participate in their chemical reactions, we need atom-specific probes of charge and bonding at both metal and ligand atomic sites. X-ray absorption spectroscopy (XAS) affords us this opportunity and is used to study the electro- and photo-catalytic reaction mechanisms of these complexes, with a specific focus on the role of metal versus ligand atomic sites. Static soft x-ray XAS studies of Nickle dithiolene catalysts at the Ni L-edge and S K-edge will be presented to resolve the electronic structure of these complexes. Static and transient XAS of Nickle aminothiolate complexes at the Ni K-edge will be presented to resolve their electro- and photo-catalytic reaction mechanisms. These results highlight the unique ability of x-ray spectroscopy to clarify the role of redox-active ligands during catalysis.