Sensitivity of time‐resolved diffraction data to changes in internuclear distances and atomic positions

Abstract

Time-resolved x-ray liquidography (TRXL) is a powerful technique to study molecular structural dynamics in the solution phase. Typically, a TRXL experiment is conducted during limited beamtime at a beamline of a synchrotron or an x-ray free-electron laser, demanding a proper design and careful planning. In this regard, the optimal q range needs to be determined to find the optimal x-ray energy and sample-to-detector distance. For such purpose, here, we present effective ways to quantify the sensitivity of the TRXL data as a function of q to various factors such as the atomic positions, internuclear distances, solvent cage, and bulk solvent. The developed approaches are also applicable to other types of time-resolved diffraction, such as ultrafast electron diffraction.

Cerium Photocatalyst in Action: Structural Dynamics in the Presence of Substrate Visualized via Time-Resolved X-ray Liquidography

“…To quantitatively estimate the sensitivity of the TRXL signal to the C–I bond dissociation or the contribution of the C–I bond dissociation to the TRXL signal, we generated a sensitivity plot for the reaction investigated in this work (Figure S7). In terms of interatomic distances, the darkness of the line in the sensitivity plot denotes the degree of contribution of a particular interatomic distance to the TRXL signal, with darker lines indicating more dominant contributions. Meanwhile, in terms of the positions of atoms, the size of the circle in the sensitivity plot denotes the degree of contribution of an atomic position to the TRXL signal, with larger circles indicating more dominant contributions.…”

Photoexcitation dynamics of azide ion bound ferric myoglobin probed by femtosecond infrared spectroscopy

“…Details of the TR spectrometer have been described elsewhere. 17 In short, an intense 800 nm pulse with a repetition rate of 1 kHz from a Ti:sapphire amplifier pumped two optical parametric amplifiers (OPAs), [18][19][20][21][22] which generated a visible pump pulse and a mid-IR probe pulse. Frequency doubling of a signal pulse from one OPA generated a 3 μJ visible pump pulse at 575 nm, and difference frequency mixing of the signal and idler pulses from the other OPA produced a tunable mid-IR probe pulse.…”