Berrah, Nora: Ultrafast photon induced molecular dynamics using table-top lasers and free electron lasers
ORAL · Invited
Abstract
Berrah, Nora: Ultrafast photon induced molecular dynamics using table-top lasers and free electron lasers
Molecules upon photoexcitation can undergo numerous processes leading to changes in their nuclear and electronic structure. Some of these changes can be isomerization, roaming, or in the case of ring molecules, dissociation or ring opening.
We will report on time resolved ultrafast nuclear dynamics initiated by photon excitation and ionization generated from either table-top lasers or free electron lasers (FELs). We have carried out experiments using pump–probe spectroscopy in combination with either coincident Coulomb explosion imaging or photoelectron spectroscopy. Specifically, we will describe different isomerization pathways including roaming in acetonitrile [1] and methanol as well as demonstrate in 2-bromothiophene, two- and three- body molecular fragmentation channels that display dynamics ranging from direct bromine dissociation to ring opening and fragmentation. All measurements are paired with state-of-the-art calculations to identify or interpret the observed mechanisms. In the case of acetonitrile, theoretical calculations predict unobserved isomerization pathways such as cyclic and unique linear isomers for which we will present preliminary experimental results.
[1] D.Mishra*, A. C. LaForge*, S. Diaz-Tendero, F. Martin, and N. Berrah, Nature Comm. 15, 6656 (2024).
*Work done with D. Mishra, A.C. LaForge, N. Frese, C. Brady, C. Bray, S. Diaz-Tendero, F. Martin, J. Gascon, A. Rossi, M. R. Thomas, N. Golubev, the collaborations of LCLS proposal No. L10309 and FERMI proposal No. 20234045.
Molecules upon photoexcitation can undergo numerous processes leading to changes in their nuclear and electronic structure. Some of these changes can be isomerization, roaming, or in the case of ring molecules, dissociation or ring opening.
We will report on time resolved ultrafast nuclear dynamics initiated by photon excitation and ionization generated from either table-top lasers or free electron lasers (FELs). We have carried out experiments using pump–probe spectroscopy in combination with either coincident Coulomb explosion imaging or photoelectron spectroscopy. Specifically, we will describe different isomerization pathways including roaming in acetonitrile [1] and methanol as well as demonstrate in 2-bromothiophene, two- and three- body molecular fragmentation channels that display dynamics ranging from direct bromine dissociation to ring opening and fragmentation. All measurements are paired with state-of-the-art calculations to identify or interpret the observed mechanisms. In the case of acetonitrile, theoretical calculations predict unobserved isomerization pathways such as cyclic and unique linear isomers for which we will present preliminary experimental results.
[1] D.Mishra*, A. C. LaForge*, S. Diaz-Tendero, F. Martin, and N. Berrah, Nature Comm. 15, 6656 (2024).
*Work done with D. Mishra, A.C. LaForge, N. Frese, C. Brady, C. Bray, S. Diaz-Tendero, F. Martin, J. Gascon, A. Rossi, M. R. Thomas, N. Golubev, the collaborations of LCLS proposal No. L10309 and FERMI proposal No. 20234045.
*This work is funded by the DOE, Chemical Sciences, Geosciences and Biosciences Division, Office of Basic Energy Sciences, Office of Science, under award No. DE-SC0012376 and award No. DE-SC0024182. The NSF under award No. 2306982. The MICINN - Spanish Ministry of Science and Innovation−Ministerio Espanol de Ciencia e Innovacion for Projects PID2019-105458RB-I00 and PID2022-138470NB-I00. The LCLS at SLAC Nat. Lab. is funded by DOE, BES under award No. DE-AC02-76SF00515
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Publication: D.Mishra*, A. C. LaForge*, S. Diaz-Tendero, F. Martin, and N. Berrah, Nature Comm. 15, 6656 (2024).
Presenters
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Nora Berrah
- University of Connecticut