Time resolved X-ray absorption spectroscopy in condensed matter: A road map to the future

Dell’Angela, Martina; Parmigiani, Fulvio; Malvestuto, Marco

doi:10.1016/j.elspec.2015.06.014

Cited by 8 publications

(3 citation statements)

References 99 publications

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“…Electron transfer is an important process in biology 1,2 , catalysis [3][4][5] , and artificial photosynthesis 6,7 . The environment (e.g., a solvent) plays an important active role in this process, rather than being a passive spectator [8][9][10][11][12][13] , and recent advances with time-resolved techniques, including X-ray spectroscopy, have given new insight into how the nonequilibrium dynamics of the environment affects electron transfer [14][15][16][17][18][19][20][21][22][23] . For example, for transition metal complexes, solvation dynamics strongly modulate intramolecular electron transfer and localization, rather than just perturbing it 21 .…”

Section: Introductionmentioning

confidence: 99%

Solvent dynamics of aqueous halides before and after photoionization

Reidelbach

Schneeberger

Zöllner

et al. 2022

Preprint

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Electron transfer reactions can be strongly influenced by solvent dynamics. We study the photoionization of halides in water as a model system for such reactions. There are no internal nuclear degrees of freedom in the solute, allowing to uniquely identify the dynamics of the solvent. We simulate the equilibrium solvent dynamics for Cl$^-$, Br$^-$, I$^-$ and their respective neutral atoms in water, comparing quantum mechanical/molecular mechanical (QM/MM) and classical molecular dynamics (MD) methods. On the basis of the obtained configurations, we calculate the extended X-Ray fine structure (EXAFS) spectra rigorously based on the MD snapshots and compare in detail with other theoretical and experimental results available in the literature. We find our EXAFS spectra based on QM/MM MD simulations in good agreement with their experimental counterparts for the ions. Classical MD simulations for the ions lead to EXAFS spectra that agree equally well with the experiment when it comes to the oscillatory period of the signal, even though they differ from the QM/MM radial distribution functions extracted from the MD. The amplitude is, however, considerably overestimated. This suggests that to judge the reliability of theoretical simulation methods or to elucidate fine details of the atomistic dynamics of the solvent based on EXAFS spectra, the amplitude and not only the oscillatory period need to be considered. If simulations fail qualitatively, as does the classical MD for the aqueous halogen atoms, the resulting EXAFS will also be strongly affected in both oscillatory period and amplitude. The good reliability of QM/MM-based EXAFS simulations, together with clear qualitative differences in the EXAFS spectra found between halides and their atomic counterparts, suggests that a combined theory and experimental EXAFS approach is suitable for elucidating the nonequilibrium solvent dynamics in the photoionization of halides, and possibly also for electron transfer reactions in more complex systems.

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Section: Introductionmentioning

confidence: 99%

Solvent dynamics of aqueous halides before and after photoionization

Reidelbach

Schneeberger

Zöllner

et al. 2022

Preprint

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show abstract

“…Quasi-continuous harmonic spectra as generated by few-cycle pulses can be applied to NEXAFS spectroscopy [86] that can potentially be combined with pump-probe techniques to study ultrafast dynamics [220]. For example, the two spectra shown in figure 10(b) allow information on the used parylene filter and its chemical structure at the carbon K-edge to be obtained, as shown in figure 20.…”

Section: Near Edge X-ray Absorption Fine Structure (Nexafs) Spectroscopymentioning

confidence: 99%

Single-pass high harmonic generation at high repetition rate and photon flux

Hädrich

Rothhardt

Krebs

et al. 2016

J. Phys. B: At. Mol. Opt. Phys.

122

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Sources of short wavelength radiation with femtosecond to attosecond pulse durations, such as synchrotrons or free electron lasers, have already made possible numerous, and will facilitate more, seminal studies aimed at understanding atomic and molecular processes on fundamental length and time scales. Table-top sources of coherent extreme ultraviolet to soft x-ray radiation enabled by high harmonic generation (HHG) of ultrashort pulse lasers have also gained significant attention in the last few years due to their enormous potential for addressing a plethora of applications, therefore constituting a complementary source to large-scale facilities (synchrotrons and free electron lasers). Ti:sapphire based laser systems have been the workhorses for HHG for decades, but are limited in repetition rate and average power. On the other hand, it has been widely recognized that fostering applications in fields such as photoelectron spectroscopy and microscopy, coincidence detection, coherent diffractive imaging and frequency metrology requires a high repetition rate and high photon flux HHG sources. In this article we will review recent developments in realizing the demanding requirement of producing a high photon flux and repetition rate at the same time. Particular emphasis will be put on suitable ultrashort pulse and high average power lasers, which directly drive harmonic generation without the need for external enhancement cavities. To this end we describe two complementary schemes that have been successfully employed for high power fiber lasers, i.e. optical parametric chirped pulse amplifiers and nonlinear pulse compression. Moreover, the issue of phase-matching in tight focusing geometries will be discussed and connected to recent experiments. We will highlight the latest results in fiber laser driven high harmonic generation that currently produce the highest photon flux of all existing sources. In addition, we demonstrate the first promising applications and discuss the future direction and challenges of this new type of HHG source.

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“…Electron transfer is an important process in biology, , catalysis, − and artificial photosynthesis. , The environment (e.g., a solvent) plays an important active role in this process, rather than being a passive spectator, − and recent advances with time-resolved techniques, including X-ray spectroscopy, have given new insight into how the nonequilibrium dynamics of the environment affects electron transfer. − For example, for transition metal complexes, solvation dynamics strongly modulate intramolecular electron transfer and localization, rather than just perturbing it …”

Section: Introductionmentioning

confidence: 99%

Solvent Dynamics of Aqueous Halides before and after Photoionization

et al. 2023

View full text Add to dashboard Cite

Electron transfer reactions can be strongly influenced by solvent dynamics. We study the photoionization of halides in water as a model system for such reactions. There are no internal nuclear degrees of freedom in the solute, allowing the dynamics of the solvent to be uniquely identified. We simulate the equilibrium solvent dynamics for Cl–, Br–, I–, and their respective neutral atoms in water, comparing quantum mechanical/molecular mechanical (QM/MM) and classical molecular dynamics (MD) methods. On the basis of the obtained configurations, we calculate the extended X-ray absorption fine structure (EXAFS) spectra rigorously based on the MD snapshots and compare them in detail with other theoretical and experimental results available in the literature. We find our EXAFS spectra based on QM/MM MD simulations in good agreement with their experimental counterparts for the ions. Classical MD simulations for the ions lead to EXAFS spectra that agree equally well with the experiment when it comes to the oscillatory period of the signal, even though they differ from the QM/MM radial distribution functions extracted from the MD. The amplitude is, however, considerably overestimated. This suggests that to judge the reliability of theoretical simulation methods or to elucidate fine details of the atomistic dynamics of the solvent based on EXAFS spectra, the amplitude as well as the oscillatory period need to be considered. If simulations fail qualitatively, as does the classical MD for the aqueous neutral halogen atoms, the resulting EXAFS will also be strongly affected in both oscillatory period and amplitude. The good reliability of QM/MM-based EXAFS simulations, together with clear qualitative differences in the EXAFS spectra found between halides and their atomic counterparts, suggests that a combined theory and experimental EXAFS approach is suitable for elucidating the nonequilibrium solvent dynamics in the photoionization of halides and possibly also for electron transfer reactions in more complex systems.

show abstract

Time resolved X-ray absorption spectroscopy in condensed matter: A road map to the future

Cited by 8 publications

References 99 publications

Solvent dynamics of aqueous halides before and after photoionization

Solvent dynamics of aqueous halides before and after photoionization

Single-pass high harmonic generation at high repetition rate and photon flux

Solvent Dynamics of Aqueous Halides before and after Photoionization

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