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Title: Vibrationally resolved high-resolution NEXAFS and XPS spectra of phenanthrene and coronene

Journal Article · · Journal of Chemical Physics
DOI:https://doi.org/10.1063/1.4891221· OSTI ID:22419941
; ;  [1]; ;  [2];  [2]; ;  [3]; ;  [4];  [5]
  1. Dipartimento di Scienze Chimiche e Farmaceutiche, Università di Trieste, Via L. Giorgieri 1, I-34127 Trieste (Italy)
  2. Department of Theoretical Chemistry and Biology, School of Biotechnology, Royal Institute of Technology, S-106 91 Stockholm (Sweden)
  3. Istituto di Ricerche sulla Combustione, IRC-CNR, P.le Tecchio, 80, 80125 Napoli (Italy)
  4. CNR-IOM, Laboratorio TASC, 34149 Trieste (Italy)
  5. CNR-IMIP, 00016 Montelibretti (Italy)

We performed a combined experimental and theoretical study of the C1s Near-Edge X-ray Absorption Fine-Structure (NEXAFS) spectroscopy and X-ray Photoelectron Spectroscopy in the gas phase of two polycyclic aromatic hydrocarbons (phenanthrene and coronene), typically formed in combustion reactions. In the NEXAFS of both molecules, a double-peak structure appears in the C1s → LUMO region, which differ by less than 1 eV in transition energies. The vibronic coupling is found to play an important role in such systems. It leads to weakening of the lower-energy peak and strengthening of the higher-energy one because the 0 − n (n > 0) vibrational progressions of the lower-energy peak appear in nearly the same region of the higher-energy peak. Vibrationally resolved theoretical spectra computed within the Frank-Condon (FC) approximation and linear coupling model agree well with the high-resolution experimental results. We find that FC-active normal modes all correspond to in-plane vibrations.

OSTI ID:
22419941
Journal Information:
Journal of Chemical Physics, Vol. 141, Issue 4; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-9606
Country of Publication:
United States
Language:
English