skip to main content

Title: Dissociation of chloromethanes upon resonant σ{sup *} excitation studied by x-ray scattering

The dissociation process following the Cl K-shell excitation to σ{sup *} resonances is studied by high resolution spectroscopy of resonant elastic and inelastic x-ray scattering on CH{sub 3}Cl, CH{sub 2}Cl{sub 2}, CHCl{sub 3}, and CCl{sub 4} molecules. Calculations employing the transition potential and Delta-Kohn-Sham DFT approach are in good agreement with the measured total fluorescence yield and show the presence of a second quasidegenerate group of states with σ{sup *} character above the lowest σ{sup *} unoccupied molecular orbital for molecules with more than one Cl atom. A bandwidth narrowing and a nonlinear dispersion behavior is extracted from the Kα spectral maps for both σ{sup *} resonances. The fitted data indicate that the widths of the Franck-Condon distributions for the first and second σ{sup *} resonances are comparable for all the molecules under study. In addition, an asymmetric broadening of the emission peaks is observed for resonant elastic x-ray scattering with zero detuning on both σ{sup *} resonances. This is attributed to the fast dissociation, transferring about 0.15 of the scattering probability into higher vibrational modes.
Authors:
; ;  [1] ;  [1] ;  [2] ; ; ; ;  [3] ;  [4] ;  [5] ;  [6]
  1. Jožef Stefan Institute, Jamova cesta 39, SI-1000 Ljubljana (Slovenia)
  2. (Slovenia)
  3. UPMC, Université Paris 06, CNRS, UMR 7614, LCPMR, 11 rue Pierre et Marie Curie, 75231, Paris Cedex 05 (France)
  4. Department of Physics, University of Oulu, P.O. Box 3000, FIN-90014 Oulu (Finland)
  5. (Switzerland)
  6. (Canada)
Publication Date:
OSTI Identifier:
22220402
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Chemical Physics; Journal Volume: 139; Journal Issue: 13; Other Information: (c) 2013 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; 74 ATOMIC AND MOLECULAR PHYSICS; CARBON TETRACHLORIDE; CHLOROFORM; DENSITY FUNCTIONAL METHOD; DISSOCIATION; EXCITATION; FLUORESCENCE; METHYL CHLORIDE; METHYLENE CHLORIDE; REACTION KINETICS; SPECTROSCOPY; VIBRATIONAL STATES; X-RAY DIFFRACTION; X-RAY SPECTRA