1. All-XUV Pump-Probe Transient Absorption Spectroscopy of the Structural Molecular Dynamics of Di-iodomethane
- Author
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Rebholz, Marc, Ding, Thomas, Despré, Victor, Aufleger, Lennart, Hartmann, Maximilian, Meyer, Kristina, Stooß, Veit, Magunia, Alexander, Wachs, David, Birk, Paul, Mi, Yonghao, Borisova, Gergana Dimitrova, da Costa Castanheira, Carina, Rupprecht, Patrick, Schmid, Georg, Schnorr, Kirsten, Schröter, Claus Dieter, Moshammer, Robert, Loh, Zhi-Heng, Attar, Andrew R, Leone, Stephen R, Gaumnitz, Thomas, Wörner, Hans Jakob, Roling, Sebastian, Butz, Marco, Zacharias, Helmut, Düsterer, Stefan, Treusch, Rolf, Brenner, Günter, Vester, Jonas, Kuleff, Alexander I, Ott, Christian, and Pfeifer, Thomas
- Subjects
Atomic ,Molecular and Optical Physics ,Physical Sciences ,Astronomical and Space Sciences ,Condensed Matter Physics ,Quantum Physics ,Physical sciences - Abstract
In this work, we use an extreme-ultraviolet (XUV) free-electron laser (FEL) to resonantly excite the I: 4d5/2-σ∗ transition of a gas-phase di-iodomethane (CH2I2) 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