Mechanistic insights into bio- and electrocatalytic reactions from EPR spectroscopy.
Dr. Maxie Rößler
Imperial College London, Department of Chemistry and Centre for Pulse EPR Spectroscopy
Unpaired electrons play an important role in numerous redox-driven catalytic processes. Controlling their location and exploiting the interactions with their environment can provide key mechanistic information into these catalytic reactions. In this talk I will discuss how we are exploiting and developing EPR-based techniques in conjunction with biochemistry, electrochemistry and materials chemistry to gain mechanistic insights into metalloenzymes1 and electrocatalysts.
I will discuss some insights that pulse EPR has brought to understanding how complex membrane proteins, respiratory complex I and its homologue in photosynthesis,2 function. I will further show ongoing work that considers the importance of the membrane.3
I will then introduce film-electrochemical EPR spectroscopy (FE‑EPR)4 as a new tool to investigate surface-bound molecular catalysts. With in situ and operando FE-EPR we can monitor the evolution of radicals during catalysis in real time, providing a novel way to benchmark such electrocatalysts. Our current work is focussed on extending FE‑EPR to metalloenzymes.
1. K. H. Richardson, M. Seif-Eddine, A. Sills and M. M. Roessler, Methods Enzymol, 2022, 666, 233–296.
2. K. H. Richardson, J. J. Wright, M. Šimėnas, J. Thiemann, A. M. Esteves, G. McGuire, W. K. Myers, J. J. L. Morton, M. Hippler, M. M. Nowaczyk, G. T. Hanke and M. M. Roessler, Nature Communications 2021 12:1, 2021, 12, 1–8.
3. J. Eisermann, J. J. Wright, J. D. E. T. Wilton-Ely, J. Hirst and M. M. Roessler, RSC Chem Biol, 2023, DOI:10.1039/D2CB00158F.
4. K. Abdiaziz, E. Salvadori, K. P. Sokol, E. Reisner and M. M. Roessler, Chemical Communications, 2019, 55, 8840–8843.
5. M. Seif-Eddine, K. Abdiaziz, S. Cobb, M. Bajada, E. Reisner and M. M. Roessler, under review.