Tracking structural solvent reorganization and recombination dynamics following e-photoabstraction from aqueous I-with femtosecond x-ray spectroscopy and scattering
(2022) In Journal of Chemical Physics 157(22).- Abstract
We present a sub-picosecond resolved investigation of the structural solvent reorganization and geminate recombination dynamics following 400 nm two-photon excitation and photodetachment of a valence p electron from the aqueous atomic solute, I-(aq). The measurements utilized time-resolved X-ray Absorption Near Edge Structure (TR-XANES) spectroscopy and X-ray Solution Scattering (TR-XSS) at the Linac Coherent Light Source x-ray free electron laser in a laser pump/x-ray probe experiment. The XANES measurements around the L1-edge of the generated nascent iodine atoms (I0) yield an average electron ejection distance from the iodine parent of 7.4 ± 1.5 Å with an excitation yield of about 1/3 of the 0.1M NaI aqueous solution. The kinetic... (More)
We present a sub-picosecond resolved investigation of the structural solvent reorganization and geminate recombination dynamics following 400 nm two-photon excitation and photodetachment of a valence p electron from the aqueous atomic solute, I-(aq). The measurements utilized time-resolved X-ray Absorption Near Edge Structure (TR-XANES) spectroscopy and X-ray Solution Scattering (TR-XSS) at the Linac Coherent Light Source x-ray free electron laser in a laser pump/x-ray probe experiment. The XANES measurements around the L1-edge of the generated nascent iodine atoms (I0) yield an average electron ejection distance from the iodine parent of 7.4 ± 1.5 Å with an excitation yield of about 1/3 of the 0.1M NaI aqueous solution. The kinetic traces of the XANES measurement are in agreement with a purely diffusion-driven geminate iodine-electron recombination model without the need for a long-lived (I0:e-) contact pair. Nonequilibrium classical molecular dynamics simulations indicate a delayed response of the caging H2O solvent shell and this is supported by the structural analysis of the XSS data: We identify a two-step process exhibiting a 0.1 ps delayed solvent shell reorganization time within the tight H-bond network and a 0.3 ps time constant for the mean iodine-oxygen distance changes. The results indicate that most of the reorganization can be explained classically by a transition from a hydrophilic cavity with a well-ordered first solvation shell (hydrogens pointing toward I-) to an expanded cavity around I0 with a more random orientation of the H2O molecules in a broadened first solvation shell.
(Less)
- author
- organization
- publishing date
- 2022-12-14
- type
- Contribution to journal
- publication status
- published
- subject
- in
- Journal of Chemical Physics
- volume
- 157
- issue
- 22
- article number
- 224201
- publisher
- American Institute of Physics (AIP)
- external identifiers
-
- pmid:36546808
- scopus:85144225425
- ISSN
- 0021-9606
- DOI
- 10.1063/5.0107224
- language
- English
- LU publication?
- yes
- id
- 9e144828-0b6d-4cf3-b6dc-7f16d2d24e86
- date added to LUP
- 2023-01-05 18:01:01
- date last changed
- 2024-04-18 17:43:11
@article{9e144828-0b6d-4cf3-b6dc-7f16d2d24e86,
abstract = {{<p>We present a sub-picosecond resolved investigation of the structural solvent reorganization and geminate recombination dynamics following 400 nm two-photon excitation and photodetachment of a valence p electron from the aqueous atomic solute, I-(aq). The measurements utilized time-resolved X-ray Absorption Near Edge Structure (TR-XANES) spectroscopy and X-ray Solution Scattering (TR-XSS) at the Linac Coherent Light Source x-ray free electron laser in a laser pump/x-ray probe experiment. The XANES measurements around the L1-edge of the generated nascent iodine atoms (I0) yield an average electron ejection distance from the iodine parent of 7.4 ± 1.5 Å with an excitation yield of about 1/3 of the 0.1M NaI aqueous solution. The kinetic traces of the XANES measurement are in agreement with a purely diffusion-driven geminate iodine-electron recombination model without the need for a long-lived (I0:e-) contact pair. Nonequilibrium classical molecular dynamics simulations indicate a delayed response of the caging H2O solvent shell and this is supported by the structural analysis of the XSS data: We identify a two-step process exhibiting a 0.1 ps delayed solvent shell reorganization time within the tight H-bond network and a 0.3 ps time constant for the mean iodine-oxygen distance changes. The results indicate that most of the reorganization can be explained classically by a transition from a hydrophilic cavity with a well-ordered first solvation shell (hydrogens pointing toward I-) to an expanded cavity around I0 with a more random orientation of the H2O molecules in a broadened first solvation shell.</p>}},
author = {{Vester, Peter and Kubicek, Katharina and Alonso-Mori, Roberto and Assefa, Tadesse A. and Biasin, Elisa and Christensen, Morten and Dohn, Asmus O. and Van Driel, Tim B. and Galler, Andreas and Gawelda, Wojciech and Harlang, Tobias C.B. and Henriksen, Niels E. and Kjær, Kasper S. and Kuhlman, Thomas S. and Németh, Zoltán and Nurekeyev, Zhangatay and Pápai, Mátyás and Rittman, Jochen and Vankó, György and Yavas, Hasan and Zederkof, Diana B. and Bergmann, Uwe and Nielsen, Martin M. and Møller, Klaus B. and Haldrup, Kristoffer and Bressler, Christian}},
issn = {{0021-9606}},
language = {{eng}},
month = {{12}},
number = {{22}},
publisher = {{American Institute of Physics (AIP)}},
series = {{Journal of Chemical Physics}},
title = {{Tracking structural solvent reorganization and recombination dynamics following e<sup>-</sup>photoabstraction from aqueous I<sup>-</sup>with femtosecond x-ray spectroscopy and scattering}},
url = {{http://dx.doi.org/10.1063/5.0107224}},
doi = {{10.1063/5.0107224}},
volume = {{157}},
year = {{2022}},
}