Electronic and solvent reorganization in proton-coupled electron transfer captured by ultrafast X-rays

Article Article scientifique Article Electronic and solvent reorganization in proton-coupled electron transfer captured by ultrafast X-rays eng 2026-08-26 author Kahraman Abdullah 0000-0003-1611-3061 author Sachs Michael 0000-0001-9775-9336 author Ghosh Soumen 0000-0003-0850-4855 author Poulter Benjamin I. 0000-0002-2007-0319 author Sucre Rosales Estefania 0000-0002-5486-4264 975471 author Ryland Elizabeth S. 0000-0002-9200-1769 author Garratt Douglas 0000-0002-8637-9984 author Raj Sumana L. author Powers-Riggs Natalia author Kundu Subhradip 0000-0002-3610-7008 966058 Chimie physique (groupe 3) (CHIF3) author Hampton Christina Y. author Hoffman David J. 0000-0001-8518-7676 author Coslovich Giacomo 0000-0002-1601-1287 author Dakovski Georgi L. author Kramer Patrick L. author Chollet Matthieu 0000-0002-9629-890X author Alonso-Mori Roberto 0000-0002-5357-0934 author van Driel Tim B. author Lee Sang-Jun 0000-0002-8199-3993 author Kunnus Kristjan author Cordones Amy A. 0000-0001-9897-5380 author Schoenlein Robert W. 0000-0002-6066-7566 author Vauthey Eric 0000-0002-9580-9683 133895 Département de chimie physique (CHIFI) author Andersen Amity author Govind Niranjan 0000-0003-3625-366X author Larsen Christopher B. 0000-0003-3006-2408 author Biasin Elisa 0000-0002-7276-4224 9053 10.1038/s41467-026-75943-4 2041-1723 https://www.nature.com/articles/s41467-026-75943-4 Proton-coupled electron transfer (PCET) is foundational to catalysis, bioenergetics, and energy conversion, yet directly observing the interplay between electronic redistribution, protonation, and solvent reorganization remains challenging. We combine femtosecond optical spectroscopy, ultrafast N K-edge X-ray absorption spectroscopy, and time-resolved X-ray solution scattering to capture the steps of a sequential PCET reaction in water with atomic-site specificity. Using a ruthenium polypyridyl model complex, we resolve the electron redistribution upon photoinduced metal-to-ligand charge transfer and subsequent ( ~ 460 ps) protonation at a ligand nitrogen, as well as the concomitant rearrangement of the first-solvation-shell. Combined with advanced electronic structure and molecular dynamics simulations, our measurements reveal a marked localization of the excited-state electron density at the protonated N site, together with a switch from N···HO to NH···O hydrogen-bonds. These results establish a multimodal X-ray framework for mechanistic insight into PCET and its control in catalysis, artificial photosynthesis, and biological energy flow. Dewey 540 38 Département de chimie physique 142 false 686 Groupe Vauthey Nature communications 17 1 f1f130f6-e94a-4f9a-82a7-008ae8cd9eab Article (Published version) Public Article_scientifique_from_crossref.pdf 1774320 application/pdf CC BY-4.0 1ba1176640fa790642521f2f87e018a563d574e80d822d12500429161b55ed6f openAccess Faculté des sciences / Section de chimie et biochimie / Département de chimie physique

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Electronic and solvent reorganization in proton-coupled electron transfer captured by ultrafast X-rays	Nature communications			2026	2	0

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Kundu, Subhradip

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