Time-resolved X-ray photoelectron spectroscopy: ultrafast dynamics in CS2 probed at the S 2p edge

Journal article

Recent developments in X-ray free-electron lasers have enabled a novel site-selective probe of coupled nuclear and electronic dynamics in photoexcited molecules, time-resolved X-ray photoelectron spectroscopy (TRXPS). We present results from a joint experimental and theoretical TRXPS study of the well-characterized ultraviolet photodissociation of CS₂, a prototypical system for understanding non-adiabatic dynamics. These results demonstrate that the sulfur 2p binding energy is sensitive to changes in the nuclear structure following photoexcitation, which ultimately leads to dissociation into CS and S photoproducts. We are able to assign the main X-ray spectroscopic features to the CS and S products via comparison to a first-principles determination of the TRXPS based on ab initio multiple-spawning simulations. Our results demonstrate the use of TRXPS as a local probe of complex ultrafast photodissociation dynamics involving multimodal vibrational coupling, nonradiative transitions between electronic states, and multiple final product channels.

Authors: Gabalski, I; Allum, F; Seidu, I; Britton, M; Brenner, G

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: American Chemical Society
• Journal: Journal of Physical Chemistry Letters
• Volume: 14
• Issue: 31
• Pages: 7126–7133
• Place of publication: United States
• Publication date: 2023-08-03
• Acceptance date: 2023-07-17
• DOI: 10.1021/acs.jpclett.3c01447
• EISSN: 1948-7185
• Pmid: 37534743
• Language: English
• Keywords: FFR
• Subjects: Photodissociation; Dissociation; Sulfur; Ionization; Ultrafast phenomena