1. All-XUV Pump-Probe Transient Absorption Spectroscopy of the Structural Molecular Dynamics of Di-iodomethane
- Author
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Marc Rebholz, Thomas Ding, Victor Despré, Lennart Aufleger, Maximilian Hartmann, Kristina Meyer, Veit Stooß, Alexander Magunia, David Wachs, Paul Birk, Yonghao Mi, Gergana Dimitrova Borisova, Carina da Costa Castanheira, Patrick Rupprecht, Georg Schmid, Kirsten Schnorr, Claus Dieter Schröter, Robert Moshammer, Zhi-Heng Loh, Andrew R. Attar, Stephen R. Leone, Thomas Gaumnitz, Hans Jakob Wörner, Sebastian Roling, Marco Butz, Helmut Zacharias, Stefan Düsterer, Rolf Treusch, Günter Brenner, Jonas Vester, Alexander I. Kuleff, Christian Ott, and Thomas Pfeifer
- Subjects
Physics ,QC1-999 - Abstract
In this work, we use an extreme-ultraviolet (XUV) free-electron laser (FEL) to resonantly excite the I: 4d_{5/2}–σ^{*} transition of a gas-phase di-iodomethane (CH_{2}I_{2}) target. This site-specific excitation generates a 4d core hole located at an iodine site, which leaves the molecule in a well-defined excited state. We subsequently measure the time-dependent absorption change of the molecule with the FEL probe spectrum centered on the same I: 4d resonance. Using ab initio calculations of absorption spectra of a transient isomerization pathway observed in earlier studies, our time-resolved measurements allow us to assign the timescales of the previously reported direct and indirect dissociation pathways. The presented method is thus sensitive to excited-state molecular geometries in a time-resolved manner, following a core-resonant site-specific trigger.
- Published
- 2021
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