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This content will become publicly available on February 14, 2019

Title: Chemical Understanding of the Limited Site-Specificity in Molecular Inner-Shell Photofragmentation

In many cases fragmentation of molecules upon inner-shell ionization is very unspecific with respect to the initially localized ionization site. Often this finding is interpreted in terms of an equilibration of internal energy into vibrational degrees of freedom after Auger decay. In this paper, we investigate the X-ray photofragmentation of ethyl trifluoroacetate upon core electron ionization at environmentally distinct carbon sites using photoelectron–photoion–photoion coincidence measurements and ab initio electronic structure calculations. For all four carbon ionization sites, the Auger decay weakens the same bonds and transfers the two charges to opposite ends of the molecule, which leads to a rapid dissociation into three fragments, followed by further fragmentation steps. Finally, the lack of site specificity is attributed to the character of the dicationic electronic states after Auger decay instead of a fast equilibration of internal energy.
Authors:
ORCiD logo [1] ;  [2] ; ORCiD logo [3] ; ORCiD logo [3] ;  [4] ;  [5] ;  [6] ;  [6] ;  [1] ; ORCiD logo [7] ;  [6] ;  [8] ;  [2]
  1. Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany). Center for Free-Electron Laser Science; The Hamburg Centre for Ultrafast Imaging, Hamburg (Germany)
  2. Lund Univ. (Sweden). Dept. of Physics
  3. Univ. of Oulu (Finland). Faculty of Science. Nano and Molecular Systems Research Unit
  4. Argonne National Lab. (ANL), Argonne, IL (United States). Chemical Sciences and Engineering Division
  5. Argonne National Lab. (ANL), Argonne, IL (United States). Chemical Sciences and Engineering Division; Northwestern Univ., Evanston, IL (United States). Dept. of Physics
  6. National Center for Scientific Research (CNRS), Paris (France). Lab. of Physical Chemistry - Matter and Radiation (LCPMR)
  7. Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany). Center for Free-Electron Laser Science; The Hamburg Centre for Ultrafast Imaging, Hamburg (Germany); Univ. of Hamburg (Germany). Dept. of Physics
  8. Univ. of Chicago, IL (United States). Dept. of Physics. James Franck Inst.; Argonne National Lab. (ANL), Argonne, IL (United States). Chemical Sciences and Engineering Division
Publication Date:
Grant/Contract Number:
AC02-06CH11357; 296338
Type:
Accepted Manuscript
Journal Name:
Journal of Physical Chemistry Letters
Additional Journal Information:
Journal Volume: 9; Journal Issue: 5; Journal ID: ISSN 1948-7185
Publisher:
American Chemical Society
Research Org:
Argonne National Lab. (ANL), Argonne, IL (United States); Univ. of Oulu (Finland)
Sponsoring Org:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22); Academy of Finland
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
OSTI Identifier:
1429065