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Title: UV absorption spectrum of the C2 Criegee intermediate CH{sub 3}CHOO

The UV spectrum of CH{sub 3}CHOO was measured by transient absorption in a flow cell at 295 K. The absolute absorption cross sections of CH{sub 3}CHOO were measured by laser depletion in a molecular beam to be (1.06 ± 0.09) × 10{sup −17} cm{sup 2} molecule{sup −1} at 308 nm and (9.7 ± 0.6) × 10{sup −18} cm{sup 2} molecule{sup −1} at 352 nm. After scaling the UV spectrum of CH{sub 3}CHOO to the absolute cross section at 308 nm, the peak UV cross section is (1.27 ± 0.11) × 10{sup −17} cm{sup 2} molecule{sup −1} at 328 nm. Compared to the simplest Criegee intermediate CH{sub 2}OO, the UV absorption band of CH{sub 3}CHOO is similar in intensity but blue shifted by 14 nm, resulting in a 20% slower photolysis rate estimated for CH{sub 3}CHOO in the atmosphere.
Authors:
 [1] ;  [2] ; ; ;  [3] ;  [1] ;  [4] ;  [3] ;  [2] ;  [2]
  1. Department of Chemistry, University of California, Berkeley, Berkeley, California 94720 (United States)
  2. (China)
  3. Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan (China)
  4. (United States)
Publication Date:
OSTI Identifier:
22420045
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Chemical Physics; Journal Volume: 141; Journal Issue: 7; Other Information: (c) 2014 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; ABSORPTION SPECTRA; COMPARATIVE EVALUATIONS; CROSS SECTIONS; LASERS; MOLECULAR BEAMS; MOLECULES; PEAKS; PHOTOLYSIS; ULTRAVIOLET SPECTRA