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Hydrogen migration reactions via low internal energy pathways in aminobenzoic acid dications

Veteläinen, Onni ; Babayan, Morsal ; Pihlava, Lassi ; Abid, Abdul Rahman ; Kivimäki, Antti LU ; Kukk, Edwin ; Walsh, Noelle LU ; Urpelainen, Samuli ; Björneholm, Olle and Huttula, Marko , et al. (2025) In Physical Chemistry Chemical Physics 27(18). p.9884-9894
Abstract

Hydrogen migration is a ubiquitous phenomenon upon dissociation of organic molecules. Here we investigate the formation of a H3O+ fragment after core-level photoionization and Auger decay in aminobenzoic acid molecules - a process that requires the migration of at least two hydrogen atoms. Using photoelectron-photoion coincidence spectroscopy, the formation of a H3O+ fragment is observed to be more probable in ortho-aminobenzoic acid than in meta- and para-aminobenzoic acid. Energy-resolved Auger electron-photoion coincidences are measured for the ortho-isomer to investigate the internal energy dependence of the fragmentation channels, most notably of those producing... (More)

Hydrogen migration is a ubiquitous phenomenon upon dissociation of organic molecules. Here we investigate the formation of a H3O+ fragment after core-level photoionization and Auger decay in aminobenzoic acid molecules - a process that requires the migration of at least two hydrogen atoms. Using photoelectron-photoion coincidence spectroscopy, the formation of a H3O+ fragment is observed to be more probable in ortho-aminobenzoic acid than in meta- and para-aminobenzoic acid. Energy-resolved Auger electron-photoion coincidences are measured for the ortho-isomer to investigate the internal energy dependence of the fragmentation channels, most notably of those producing H3O+. The corresponding fragmentation channels and their mechanisms are investigated by exploring the potential energy surface with ab initio quantum chemistry methods and molecular dynamics simulations. Excited-state modeling of dicationic ortho-aminobenzoic acid is used to interpret features in the Auger spectra and identify the electronic states contributing to the signals in the Auger electron photoion coincidence map. We show that populating low-energy excited states of the dication is sufficient to trigger hydrogen migration and produce H3O+ efficiently.

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organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Physical Chemistry Chemical Physics
volume
27
issue
18
pages
11 pages
publisher
Royal Society of Chemistry
external identifiers
  • scopus:105003871861
  • pmid:40293246
ISSN
1463-9076
DOI
10.1039/d5cp00415b
language
English
LU publication?
yes
additional info
Publisher Copyright: © 2025 The Royal Society of Chemistry.
id
d3890ac7-b6fa-4276-89c4-eb1651b0f927
date added to LUP
2025-08-11 15:16:19
date last changed
2025-08-12 04:13:36
@article{d3890ac7-b6fa-4276-89c4-eb1651b0f927,
  abstract     = {{<p>Hydrogen migration is a ubiquitous phenomenon upon dissociation of organic molecules. Here we investigate the formation of a H<sub>3</sub>O<sup>+</sup> fragment after core-level photoionization and Auger decay in aminobenzoic acid molecules - a process that requires the migration of at least two hydrogen atoms. Using photoelectron-photoion coincidence spectroscopy, the formation of a H<sub>3</sub>O<sup>+</sup> fragment is observed to be more probable in ortho-aminobenzoic acid than in meta- and para-aminobenzoic acid. Energy-resolved Auger electron-photoion coincidences are measured for the ortho-isomer to investigate the internal energy dependence of the fragmentation channels, most notably of those producing H<sub>3</sub>O<sup>+</sup>. The corresponding fragmentation channels and their mechanisms are investigated by exploring the potential energy surface with ab initio quantum chemistry methods and molecular dynamics simulations. Excited-state modeling of dicationic ortho-aminobenzoic acid is used to interpret features in the Auger spectra and identify the electronic states contributing to the signals in the Auger electron photoion coincidence map. We show that populating low-energy excited states of the dication is sufficient to trigger hydrogen migration and produce H<sub>3</sub>O<sup>+</sup> efficiently.</p>}},
  author       = {{Veteläinen, Onni and Babayan, Morsal and Pihlava, Lassi and Abid, Abdul Rahman and Kivimäki, Antti and Kukk, Edwin and Walsh, Noelle and Urpelainen, Samuli and Björneholm, Olle and Huttula, Marko and Alatalo, Matti and Patanen, Minna and Díaz-Tendero, Sergio}},
  issn         = {{1463-9076}},
  language     = {{eng}},
  month        = {{04}},
  number       = {{18}},
  pages        = {{9884--9894}},
  publisher    = {{Royal Society of Chemistry}},
  series       = {{Physical Chemistry Chemical Physics}},
  title        = {{Hydrogen migration reactions via low internal energy pathways in aminobenzoic acid dications}},
  url          = {{http://dx.doi.org/10.1039/d5cp00415b}},
  doi          = {{10.1039/d5cp00415b}},
  volume       = {{27}},
  year         = {{2025}},
}