Imaging a light-induced molecular elimination reaction with an X-ray free-electron laser
: Li, Xiang; Boll, Rebecca; Vindel-Zandbergen, Patricia; González-Vázquez, Jesús; Rivas, Daniel E.; Bhattacharyya, Surjendu; Borne, Kurtis; Chen, Keyu; De Fanis, Alberto; Erk, Benjamin; Forbes, Ruaridh; Green, Alice E.; Ilchen, Markus; Kaderiya, Balram; Kukk, Edwin; Lam, Huynh Van Sa; Mazza, Tommaso; Mullins, Terence; Senfftleben, Bjoern; Trinter, Florian; Usenko, Sergey; Venkatachalam, Anbu Selvam; Wang, Enliang; Cryan, James P.; Meyer, Michael; Jahnke, Till; Ho, Phay J.; Rolles, Daniel; Rudenko, Artem
Publisher: NATURE PORTFOLIO
: BERLIN
: 2025
: Nature Communications
: NATURE COMMUNICATIONS
: NAT COMMUN
: 7006
: 16
: 11
: 2041-1723
DOI: https://doi.org/10.1038/s41467-025-62274-z
: https://www.nature.com/articles/s41467-025-62274-z
: https://research.utu.fi/converis/portal/detail/Publication/499750391
Tracking the motion of individual atoms during chemical reactions represents a severe experimental challenge, especially if several competing reaction pathways exist or if the reaction is governed by the correlated motion of more than two molecular constituents. Here we demonstrate how ultrashort X-ray pulses combined with coincident ion imaging can be used to trace molecular iodine elimination from laser-irradiated diiodomethane (CH2I2), a reaction channel of fundamental importance but small relative yield that involves the breaking of two molecular bonds and the formation of a new one. We map bending vibrations of the bound molecule, disentangle different dissociation pathways, image the correlated motion of the iodine atoms and the methylene group leading to molecular iodine ejection, and trace the vibrational motion of the formed product. Our results provide a quantitative mechanistic picture behind previously suggested reaction mechanisms and prove that a variety of geometries are involved in the molecular bond formation.
:
K.B., B.K., H.V.S.L., E.W., D.R., and A.R. were supported by the US Department of Energy, Office of Science, Office of Basic Energy Sciences, Chemical Sciences, Geosciences, and Biosciences Division under contract no. DE-FG02-86ER13491. S.B. and K.C. were supported by contract no. DE-SC0020276, and P.J.H. was supported by the contract no. DE-AC02-06CH11357 from the same funding agency. X.L., R.F. and J.P.C. are supported by the Linac Coherent Light Source (LCLS), SLAC National Accelerator Laboratory, which is funded by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences under Contract No. DE-AC02-76SF00515. A.S.V was funded through the National Science Foundation (NSF) grant No. PHYS1753324 and, during the final phase of the project, grant No. PHYS-2409365. P.V.Z. is funded through the National Science Foundation (NSF) grants Nos. CHE-2054616 and CHE-2054604 and is grateful to the Simons Foundation for the computational resources used in this research. J.G.V thanks the projects PID2022-138288NB-C32 and PID2019-106732GB-I00 funded by MCIN/AEI/10.13039/ 501100011033 and the European Union “NextGenerationEU”/PRTRMICINN programs. A.G. was supported by the European Union Marie Curie project 101067645. F.T. acknowledges funding by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) - Project 509471550, Emmy Noether Program. M.I. was partly supported by the Bundesministerium für Bildung und Forschung (BMBF) under grant 13K22CHA. M.M. acknowledges support by the Cluster of Excellence ‘Advanced Imaging of Matter’ of the DFG—EXC 2056 and project ID 390715994.
