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Ultrafast dissociation of methanol and formic acid at the oxygen K edge

Abstract

Full text:The ultrafast dissociation of methanol and formic acid after excitation of the O 1s to 3s resonances has been studied by photoemission. The resonant decay spectrum shows two classes of features: resonantly enhanced valence bands that disperse with photon energy, and Resonant Auger peaks that are stationary in kinetic energy. On deuteration of the molecules, some stationary peaks change intensity significantly. This is the signature that they are due to decay of oxygen 1s excited methoxy (CH3O*) and formlyoxyl (HCO*2) radicals. The bond to the acid hydrogen is broken before the core decay, and deuteration slows this process. This work extends the literature on hydrogen halides, other diatomics and water to more complex molecules. In diatomics there is only one bond that can break, but in polyatomics molecules there is competition. Scission of the carbon-oxygen bond is thermodynamically more favourable, but OH bond breaking occurs because it is faster. Besides the O 1s resonant Auger decay of these species we also report the valence band resonant spectra. The whole valence band resonates and not just the symmetry allowed states, suggesting that vibronic coupling is significant.
Authors:
Prince, K C; [1]  INFM-TASC, Trieste; [2]  Richter, R; [1]  De Simone, M; [3]  Coreno, M; [4]  Farrokhpour, H; Tabrizchi, M; [5]  Isfahn University of Technology (Iran, Islamic Republic of)]
  1. Sincrotrone Trieste (Italy)
  2. Italy
  3. INFM-TASC, Trieste (Italy)
  4. CNR-IMIP, Roma (Italy)
  5. The Abdus Salam International Centre for Thoretical Physics (Italy)
Publication Date:
Jul 01, 2004
Product Type:
Conference
Resource Relation:
Conference: VUV14: 14. International Conference on Vacuum-Ultraviolet Radiation Physics, Cairns, QLD (Australia), 19-23 Jul 2004; Other Information: PBD: 2004; Related Information: In: 14th International Conference on Vacuum-Ultraviolet Radiation Physics. Program and Abstracts, 309 pages.
Subject:
74 ATOMIC AND MOLECULAR PHYSICS; COUPLING; DECAY; DEUTERATION; DISSOCIATION; EMISSION SPECTRA; FORMIC ACID; HYDROGEN; KINETIC ENERGY; METHANOL; MOLECULES; OXYGEN; PHOTOEMISSION; PHOTON-MOLECULE COLLISIONS; PHOTONS; RESONANCE; VALENCE
OSTI ID:
20601706
Research Organizations:
State Governement of Victoria (Australia); The Australian National University, Canberra, ACT (Australia)
Country of Origin:
Australia
Language:
English
Other Identifying Numbers:
TRN: AU0525359048227
Availability:
Available in abstract form only, full text entered in this record. Proceedings to be published in the Journal of Electron Spectroscopy and Related Phenomena
Submitting Site:
INIS
Size:
page(s) 145
Announcement Date:
Jul 03, 2005

Citation Formats

Prince, K C, INFM-TASC, Trieste, Richter, R, De Simone, M, Coreno, M, Farrokhpour, H, Tabrizchi, M, and Isfahn University of Technology (Iran, Islamic Republic of)]. Ultrafast dissociation of methanol and formic acid at the oxygen K edge. Australia: N. p., 2004. Web.
Prince, K C, INFM-TASC, Trieste, Richter, R, De Simone, M, Coreno, M, Farrokhpour, H, Tabrizchi, M, & Isfahn University of Technology (Iran, Islamic Republic of)]. Ultrafast dissociation of methanol and formic acid at the oxygen K edge. Australia.
Prince, K C, INFM-TASC, Trieste, Richter, R, De Simone, M, Coreno, M, Farrokhpour, H, Tabrizchi, M, and Isfahn University of Technology (Iran, Islamic Republic of)]. 2004. "Ultrafast dissociation of methanol and formic acid at the oxygen K edge." Australia.
@misc{etde_20601706,
title = {Ultrafast dissociation of methanol and formic acid at the oxygen K edge}
author = {Prince, K C, INFM-TASC, Trieste, Richter, R, De Simone, M, Coreno, M, Farrokhpour, H, Tabrizchi, M, and Isfahn University of Technology (Iran, Islamic Republic of)]}
abstractNote = {Full text:The ultrafast dissociation of methanol and formic acid after excitation of the O 1s to 3s resonances has been studied by photoemission. The resonant decay spectrum shows two classes of features: resonantly enhanced valence bands that disperse with photon energy, and Resonant Auger peaks that are stationary in kinetic energy. On deuteration of the molecules, some stationary peaks change intensity significantly. This is the signature that they are due to decay of oxygen 1s excited methoxy (CH3O*) and formlyoxyl (HCO*2) radicals. The bond to the acid hydrogen is broken before the core decay, and deuteration slows this process. This work extends the literature on hydrogen halides, other diatomics and water to more complex molecules. In diatomics there is only one bond that can break, but in polyatomics molecules there is competition. Scission of the carbon-oxygen bond is thermodynamically more favourable, but OH bond breaking occurs because it is faster. Besides the O 1s resonant Auger decay of these species we also report the valence band resonant spectra. The whole valence band resonates and not just the symmetry allowed states, suggesting that vibronic coupling is significant.}
place = {Australia}
year = {2004}
month = {Jul}
}