skip to main content

Title: Near edge X-ray absorption mass spectrometry on coronene

We have investigated the photoionization and photodissociation of free coronene cations C{sub 24}H{sub 12}{sup +} upon soft X-ray photoabsorption in the carbon K-edge region by means of a time-of-flight mass spectrometry approach. Core excitation into an unoccupied molecular orbital (below threshold) and core ionization into the continuum both leave a C 1s vacancy, that is subsequently filled in an Auger-type process. The resulting coronene dications and trications are internally excited and cool down predominantly by means of hydrogen emission. Density functional theory was employed to determine the dissociation energies for subsequent neutral hydrogen loss. A statistical cascade model incorporating these dissociation energies agrees well with the experimentally observed dehydrogenation. For double ionization, i.e., formation of intermediate C{sub 24}H{sub 12}{sup 3+⋆}trications, the experimental data hint at loss of H{sup +} ions. This asymmetric fission channel is associated with hot intermediates, whereas colder intermediates predominantly decay via neutral H loss.
Authors:
; ; ;  [1] ;  [1] ;  [2] ;  [3]
  1. Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747AG Groningen (Netherlands)
  2. (Netherlands)
  3. Van Swinderen Institute, University of Groningen, Groningen (Netherlands)
Publication Date:
OSTI Identifier:
22415832
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Chemical Physics; Journal Volume: 142; Journal Issue: 2; Other Information: (c) 2015 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; ABSORPTION; CARBON; DEHYDROGENATION; DENSITY FUNCTIONAL METHOD; DISSOCIATION; DISSOCIATION ENERGY; EXCITATION; HYDROGEN; HYDROGEN 4; HYDROGEN IONS 1 PLUS; MASS SPECTROSCOPY; MOLECULAR ORBITAL METHOD; PHOTOIONIZATION; PHOTOLYSIS; SOFT X RADIATION; TIME-OF-FLIGHT METHOD; VACANCIES