University of Illinois Urbana-Champaign

REAL-TIME MONITORING OF CHIRALITY LOSS IN MOLECULAR PHOTODISSOCIATION BY TRANSIENT X-RAY CIRCULAR DICHROISM

Nam, Yeonsig

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6687.pdf
MH08_1.pptx

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https://hdl.handle.net/2142/122473

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Title
REAL-TIME MONITORING OF CHIRALITY LOSS IN MOLECULAR PHOTODISSOCIATION BY TRANSIENT X-RAY CIRCULAR DICHROISM
Author(s)
Nam, Yeonsig
Contributor(s)
  • Cho, Daeheum
  • Mukamel, Shaul
Issue Date
2023-06-19
Keyword(s)
Mini-symposium: Spectroscopy at Large-scale Facilities
Abstract
Newly developed X-ray sources offer valuable insight on molecular dynamics with unprecedented spatiotemporal resolutions and element sensitivity. Significant advances made in the control of the polarization of X-ray beams enables real-time monitoring of molecular chirality, which is an indispensable subject for understanding and controlling biological process. We theoretically apply time- and frequency-resolved X-ray Circular dichroism (TRXCD) spectroscopy to discern the time evolution of molecular chirality at different element windows during the photodissociation of 2-iodobutane. Following an optical excitation, the iodine atom dissociates from the chiral center, which we capture by quantum nuclear dynamics simulations. A resonant X-ray pulse then probes the iodine or carbon atom through an element-specific core-to-valence transition. The TRXCD signal at the iodine L₁-edge captures the timing of chirality loss, c.a 70 fs. The strong electric dipole–electric quadrupole (ED-EQ) response at this high X-ray regime makes this signal sensitive to vibronic coherences. At the carbon K-edges, the signals re-capture the chirality of 2-butyl radical and the spin state of the iodine atom. The stronger electric-magnetic dipole response make the signals more intuitive for the electronic population than coherence. Overall, the element-specific TRXCD signal offers a unique window into the time-dependent chirality of molecules.
Publisher
International Symposium on Molecular Spectroscopy
Type of Resource
Text
Genre of Resource
Conference Paper / Presentation
Language
eng
Handle URL
https://hdl.handle.net/2142/122473
DOI
https://doi.org/10.15278/isms.2023.6687

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Abstracts & Presentations - 2023 International Symposium on Molecular Spectroscopy PRIMARY