@article{120b6b97ae15493f9e79c6c9269e48b2,
title = "X-Ray absorption spectroscopy of H3O+",
abstract = "We report the X-ray absorption of isolated H3O+ cations at the O 1s edge. The molecular ions were prepared in a flowing afterglow ion source which was designed for the production of small water clusters, protonated water clusters, and hydrated ions. Isolated H2O+ cations have been analyzed for comparison. The spectra show significant differences in resonance energies and widths compared to neutral H2O with resonances shifting to higher energies by as much as 10 eV and resonance widths increasing by as much as a factor of 5. The experimental results are supported by time-dependent density functional theory calculations performed for both molecular cations, showing a good agreement with the experimental data. The spectra reported here could enable the identification of the individual molecules in charged small water clusters or liquid water using X-ray absorption spectroscopy.",
author = "Julius Schwarz and Fridtjof Kielgast and Ivan Baev and Simon Reinwardt and Florian Trinter and Stephan Klumpp and Alexander Perry-Sassmannshausen and Ticia Buhr and Stefan Schippers and Alfred M{\"u}ller and Sadia Bari and Valerie Mondes and Roman Flesch and Eckart R{\"u}hl and Michael Martins",
note = "Funding Information: We acknowledge DESY (Hamburg, Germany), a member of the Helmholtz Association HGF, for the provision of experimental facilities. Parts of this research were carried out at PETRA III and we would like to thank the team of beamline P04 for assistance in using P04 and PIPE. Beamtime was allocated for proposal I-20190066. Funding was provided by the German Ministry of Education and Research (BMBF), contracts 05K16GUC, 05K16RG1, O5K19RG3, and 05K19GU3 and the Deutsche Forschungsgemeinschaft (DFG), projects SFB925/A3 and 389115454 (Schi378/12). E. R{\"u}hl acknowledges financial support by BMBF (contracts 05KS7KE1 and 05K10KEA). S. Bari acknowledges funding by the Helmholtz Initiative and Networking Fund through the Young Investigator Groups Program. F. Trinter acknowledges support by the MaxWater initiative of the Max-Planck-Gesellschaft. This research was supported by the Centre for Molecular Water Science (CMWS) in an Early Science Project. Publisher Copyright: {\textcopyright} 2022 The Royal Society of Chemistry.",
year = "2022",
month = aug,
day = "24",
doi = "10.1039/d2cp02383k",
language = "English",
volume = "24",
pages = "23119--23127",
journal = "Physical Chemistry Chemical Physics",
issn = "1463-9076",
publisher = "ROYAL SOC CHEMISTRY",
number = "38",
}