Electron and X‐Ray Methods of Ultrafast Structural Dynamics: Advances and Applications

Abstract

In this contribution, we highlight the state of the art in the determination of structures with ultrafast electrons and X-rays. We provide our perspectives and reflections on the principles, techniques and methods, and on applications from different disciplines, with some focus on physical, chemical and biological structures. Although this article is not a survey of all the work done with these techniques, it provides a comprehensive referencing to current research.

Spin-state studies with XES and RIXS: From static to ultrafast

“…50-100 ps, due to the intrinsic X-ray pulse width in this range. In nearly all these cases, such studies on molecular systems have employed X-ray absorption spectroscopy [24,25,26] or X-ray scattering (XRS) techniques [25,27,28,29,30,31,32] only and have been, with few exceptions, limited to low repetition rates (ca. 1 kHz) by using Ti:sapphirebased amplified laser systems, which deliver a sufficient number of optical photons to match the number of ground state molecules in the laser beam [24].…”

Photo-Induced Pyridine Substitution in cis-[Ru(bpy)2(py)2]Cl2: A Snapshot by Time-Resolved X-ray Solution Scattering

“…10,19 In the last few years, time-resolved XAS (X-ray Absorption Spectroscopy) has been successfully employed for studying excited-state structures in solution, as demonstrated by the work of several authors. [20][21][22][23][24][25] Direct observation of structural dynamics with atomic resolution can be also obtained by TR-WAXS (Time-Resolved Wide Angle X-ray Scattering). This young technique has been used to characterize light-induced structural changes in solution for a variety of systems ranging from diatomic molecules 26 to large biomolecules.…”

Spatial Separation of Molecular Conformers and Clusters

“…Similarly the production of molecular clusters in a beam source does not result in a single species, but rather in the formation of a "cluster soup", containing many different cluster stoichiometries, as well as remaining pure parent molecules. This makes the study of these systems with novel techniques such as imaging of molecular orbitals 2 , molecular-frame photoelectron angular distributions [3][4][5] or electron [6][7][8][9][10] and X-ray diffraction [11][12][13] difficult, as these require pure, consistent, and homogenous samples in the gas-phase.…”