Ultrafast X-ray probes of elementary molecular events

D Keefer, SM Cavaletto, JR Rouxel… - Annual Review of …, 2023 - annualreviews.org
Elementary events that determine photochemical outcomes and molecular functionalities
happen on the femtosecond and subfemtosecond timescales. Among the most ubiquitous …

Attosecond electron microscopy and diffraction

D Hui, H Alqattan, M Sennary, NV Golubev… - Science …, 2024 - science.org
Advances in attosecond spectroscopy have enabled tracing and controlling the electron
motion dynamics in matter, although they have yielded insufficient information about the …

Imaging conical intersection dynamics during azobenzene photoisomerization by ultrafast X-ray diffraction

D Keefer, F Aleotti, JR Rouxel… - Proceedings of the …, 2021 - National Acad Sciences
X-ray diffraction is routinely used for structure determination of stationary molecular samples.
Modern X-ray photon sources, eg, from free-electron lasers, enable us to add temporal …

Conical intersection passages of molecules probed by X-ray diffraction and stimulated Raman spectroscopy

Y Nam, D Keefer, A Nenov, I Conti… - The Journal of …, 2021 - ACS Publications
Conical intersections (CoIns) play an important role in ultrafast relaxation channels. Their
monitoring remains a formidable experimental challenge. We theoretically compare the …

Imaging purely nuclear quantum dynamics in molecules by combined x-ray and electron diffraction

H Yong, D Keefer, S Mukamel - Journal of the American Chemical …, 2022 - ACS Publications
Monitoring the motions of atoms and molecules in the course of chemical processes is a
central goal of femtochemistry. Optical spectroscopic signals are usually sensitive to …

Direct monitoring of conical intersection passage via electronic coherences in twisted x-ray diffraction

H Yong, JR Rouxel, D Keefer, S Mukamel - Physical Review Letters, 2022 - APS
Quantum coherences in electronic motions play a critical role in determining the pathways
and outcomes of virtually all photophysical and photochemical molecular processes …

Attosecond charge migration in molecules imaged by combined x-ray and electron diffraction

H Yong, S Sun, B Gu, S Mukamel - Journal of the American …, 2022 - ACS Publications
We show how ultrafast gas-phase X-ray and electron diffraction signals can be combined to
generate real-space movies of charge migration dynamics in molecules. Charge migration …

Diffractive imaging of conical intersections amplified by resonant infrared fields

D Keefer, JR Rouxel, F Aleotti, F Segatta… - Journal of the …, 2021 - ACS Publications
The fate of virtually all photochemical reactions is determined by conical intersections.
These are energetically degenerate regions of molecular potential energy surfaces that …

Time-resolved x-ray scattering of excited state structure and dynamics

H Yong, A Kirrander, PM Weber - 2023 - books.rsc.org
Directly observing atomic motions in molecules during chemical dynamics has long
constituted one of the grand challenges in chemistry. 1 The emergence of X-ray free …

Coupled electronic and nuclear motions during azobenzene photoisomerization monitored by ultrafast electron diffraction

JR Rouxel, D Keefer, F Aleotti, A Nenov… - Journal of Chemical …, 2022 - ACS Publications
Ultrafast electron diffraction is a powerful technique that can resolve molecular structures
with femtosecond and angstrom resolutions. We demonstrate theoretically how it can be …