Journal article

Absolute cross sections for dissociative electron attachment to acetylene and diacetylene

  • May, Olivier Department of Chemistry, University of Fribourg, Switzerland
  • Fedor, Juraj Department of Chemistry, University of Fribourg, Switzerland
  • Ibănescu, Bogdan C. Department of Chemistry, University of Fribourg, Switzerland
  • Allan, Michael Department of Chemistry, University of Fribourg, Switzerland
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    14.04.2008
Published in:
  • Physical Review A. - 2008, vol. 77, no. 4, p. 040701
English Absolute cross sections for the production of the two astronomy-relevant negative ions H−C≡C⁻ and H−C≡C−C≡C⁻ by dissociative electron attachment to acetylene C₂H₂ and diacetylene C₄H₂ were measured (with a ±25% error bar). Acetylene yielded the C₂H⁻ ion at an electron energy of 2.95  eV with a cross section of 3.6±0.9  pm² and also the C₂⁻ ion at 8.1  eV with a cross section of 4.1±1  pm². Diacetylene yielded the C₄H⁻ ion at 2.5  eV with a cross section of 3.0±0.8  pm² and at 5.25  eVwith a cross section of 73±17  pm². Weaker C ₄⁻ C₂H⁻, and C₂⁻ signals were also observed from diacetylene. The identity of the negative ion resonances mediating the dissociation and the consequences for the production of these ions in discharges are discussed. An alternate path for C₄H⁻ formation, from the O⁻-C₄H₂ ion-molecule reaction, was also observed.
Faculty
Faculté des sciences et de médecine
Department
Département de Chimie
Language
  • English
Classification
Chemistry
License
License undefined
Identifiers
Persistent URL
https://folia.unifr.ch/unifr/documents/300911
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