Recent advancements in X-ray light sources enable element-sensitive nonlinear spectroscopies for probing molecular chirality. We simulate X-ray absorption spectroscopy, X-ray circular dichroism (XCD), and nonlinear optical/X-ray SFG and DFG (OX SFG/DFG) signals for two prototypical chiral molecules, fenchone and cysteine. Furthermore, our multireference simulations reproduce experimental data and reveal how novel X-ray spectroscopies exploit the site- and element-sensitivity of X-rays to uncover molecular asymmetry. The XCD spectra show strong asymmetries at chiral centers, while distant atoms contribute weaker signals. The OX SFG/DFG signals, under fixed resonant optical excitation, strongly depend on the core and valence excitations. This allows us to introduce two-dimensional (2D) chirality-sensitive valence-core spectroscopy, which provides insight into the overlap between valence orbitals and local molecular asymmetry. Finally, our estimates using realistic laser and X-ray pulse parameters demonstrate that such nonlinear experiments are feasible at XFELs, offering a promising tool for investigating chiral molecules.
Nam, Yeonsig, et al. "Linear and Nonlinear X-ray Spectra of Chiral Molecules: X-ray Circular Dichroism, Sum- and Difference-Frequency Generation of Fenchone and Cysteine." Journal of Physical Chemistry Letters, vol. 16, no. 19, May. 2025. https://doi.org/10.1021/acs.jpclett.5c00389
Nam, Yeonsig, Chergui, Majed, Young, Linda, & Rouxel, Jérémy R. (2025). Linear and Nonlinear X-ray Spectra of Chiral Molecules: X-ray Circular Dichroism, Sum- and Difference-Frequency Generation of Fenchone and Cysteine. Journal of Physical Chemistry Letters, 16(19). https://doi.org/10.1021/acs.jpclett.5c00389
@article{osti_3017057,
author = {Nam, Yeonsig and Chergui, Majed and Young, Linda and Rouxel, Jérémy R.},
title = {Linear and Nonlinear X-ray Spectra of Chiral Molecules: X-ray Circular Dichroism, Sum- and Difference-Frequency Generation of Fenchone and Cysteine},
annote = {Recent advancements in X-ray light sources enable element-sensitive nonlinear spectroscopies for probing molecular chirality. We simulate X-ray absorption spectroscopy, X-ray circular dichroism (XCD), and nonlinear optical/X-ray SFG and DFG (OX SFG/DFG) signals for two prototypical chiral molecules, fenchone and cysteine. Furthermore, our multireference simulations reproduce experimental data and reveal how novel X-ray spectroscopies exploit the site- and element-sensitivity of X-rays to uncover molecular asymmetry. The XCD spectra show strong asymmetries at chiral centers, while distant atoms contribute weaker signals. The OX SFG/DFG signals, under fixed resonant optical excitation, strongly depend on the core and valence excitations. This allows us to introduce two-dimensional (2D) chirality-sensitive valence-core spectroscopy, which provides insight into the overlap between valence orbitals and local molecular asymmetry. Finally, our estimates using realistic laser and X-ray pulse parameters demonstrate that such nonlinear experiments are feasible at XFELs, offering a promising tool for investigating chiral molecules.},
doi = {10.1021/acs.jpclett.5c00389},
url = {https://www.osti.gov/biblio/3017057},
journal = {Journal of Physical Chemistry Letters},
issn = {ISSN 1948-7185},
number = {19},
volume = {16},
place = {United States},
publisher = {American Chemical Society},
year = {2025},
month = {05}}
Argonne National Laboratory (ANL), Argonne, IL (United States)
Sponsoring Organization:
European Research Council (ERC); USDOE Office of Science (SC), Basic Energy Sciences (BES). Chemical Sciences, Geosciences & Biosciences Division (CSGB)
Grant/Contract Number:
AC02-06CH11357
Other Award/Contract Number:
DE-FOA-0003176 101095012
OSTI ID:
3017057
Journal Information:
Journal of Physical Chemistry Letters, Journal Name: Journal of Physical Chemistry Letters Journal Issue: 19 Vol. 16; ISSN 1948-7185