학술논문
All-XUV Pump-Probe Transient Absorption Spectroscopy of the Structural Molecular Dynamics of Di-iodomethane
Document Type
article
Author
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; Pfeifer, Thomas
Source
Physical Review X. 11(3)
Subject
Language
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.