Transient vibration and product formation of photoexcited CS2 measured by time-resolved x-ray scattering
Abstract
We have observed details of the internal motion and dissociation channels in photoexcited carbon disulfide (CS2) using time-resolved x-ray scattering (TRXS). Photoexcitation of gas-phase CS2 with a 200 nm laser pulse launches oscillatory bending and stretching motion, leading to dissociation of atomic sulfur in under a picosecond. During the first 300 fs following excitation, we observe significant changes in the vibrational frequency as well as some dissociation of the C–S bond, leading to atomic sulfur in the both 1D and 3P states. Beyond 1400 fs, the dissociation is consistent with primarily 3P atomic sulfur dissociation. This channel-resolved measurement of the dissociation time is based on our analysis of the time-windowed dissociation radial velocity distribution, which is measured using the temporal Fourier transform of the TRXS data aided by a Hough transform that extracts the slopes of linear features in an image. The relative strength of the two dissociation channels reflects both their branching ratio and differences in the spread of their dissociation times. Measuring the time-resolved dissociation radial velocity distribution aids the resolution of discrepancies between models for dissociation proposed by prior photoelectron spectroscopy work.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Oct 28, 2022
- Source ID
- 10.1063/5.0113079
Entities
People
- Adam Kirrander
- Adi Natan
- Andrew J. Howard
- Felix Allum
- Gopal Dixit
- Ian Gabalski
- James M. Glownia
- Kareem Hegazy
- Kyle Acheson
- Malick Sere
- Matthew R. Ware
- Mengning Liang
- Michael P Minitti
- Nathan Goff
- Nicholas Werby
- Nolan Peard
- Peter M. Weber
- Philip H. Bucksbaum
- Roseanne J Sension
- Ruaridh Forbes
- Russell S Minns
- Sébastien Boutet
- Thomas J. A. Wolf
- Weronika O. Rasmus
Organizations
- Brown University
- Engineering and Physical Sciences Research Council
- Familjen Erling-Perssons Stiftelse
- Indian Institute of Technology Bombay
- Knut and Alice Wallenberg Foundation
- Leverhulme Trust
- National Institutes of Health
- National Science Foundation
- Office of Basic Energy Sciences
- SLAC National Accelerator Laboratory
- Stanford University
- University of Edinburgh
- University of Michigan
- University of Oxford
- University of Southampton