en
Scientific article
English

Hard X-ray helical dichroism of disordered molecular media

Published inNature photonics, vol. 16, p. 570-574
Publication date2022-07-04
First online date2022-07-04
Abstract

Chirality is a structural property of molecules lacking mirror symmetry that has strong implications in diverse fields, ranging from life sciences to materials science. Chirality-sensitive spectroscopic methods, such as circular dichroism, exhibit weak signal contributions on an achiral background. Helical dichroism, which is based on the orbital angular momentum (OAM) of light, offers a new approach to probe molecular chirality, but it has never been demonstrated on disordered samples. Furthermore, in the optical domain the challenge lies in the need to transfer the OAM of the photon to an electron that is localized on an ångström-size orbital. Here we overcome this challenge using hard X-rays with spiral Fresnel zone plates, which can induce an OAM. We present the helical dichroism spectra of a disordered powder sample of enantiopure salts of the molecular complex of [Fe(4,4′-diMebpy)3]2+ at the iron K edge (7.1 keV) with OAM-carrying beams. The asymmetry ratios for the helical dichroism spectra are within one to five percent for OAM beams with topological charges of one and three. These results open a new window into the studies of molecular chirality and its interaction with the OAM of light.

eng
Citation (ISO format)
ROUXEL, Jérémy R. et al. Hard X-ray helical dichroism of disordered molecular media. In: Nature photonics, 2022, vol. 16, p. 570–574. doi: 10.1038/s41566-022-01022-x
Main files (1)
Article (Published version)
accessLevelRestricted
Identifiers
ISSN of the journal1749-4885
278views
1downloads

Technical informations

Creation07/25/2022 12:06:00 PM
First validation07/25/2022 12:06:00 PM
Update time03/16/2023 7:03:03 AM
Status update03/16/2023 7:03:01 AM
Last indexation05/06/2024 11:13:57 AM
All rights reserved by Archive ouverte UNIGE and the University of GenevaunigeBlack