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Title: Communication: Spectroscopic characterization of an alkyl substituted Criegee intermediate syn-CH{sub 3}CHOO through pure rotational transitions

An alkyl-substituted Criegee intermediate syn-CH{sub 3}CHOO was detected in the gas phase through Fourier-transform microwave spectroscopy. Observed pure rotational transitions show a small splitting corresponding to the A/E components due to the threefold methyl internal rotation. The rotational constants and the barrier height of the hindered methyl rotation were determined to be A = 17 586.5295(15) MHz, B = 7133.4799(41) MHz, C = 5229.1704(40) MHz, and V{sub 3} = 837.1(17) cm{sup −1}. High-level ab initio calculations which reproduce the experimentally determined values well indicate that the in-plane C–H bond in the methyl moiety is trans to the C–O bond, and other two protons are directed to the terminal oxygen atom for the most stable structure of syn-CH{sub 3}CHOO. The torsional barrier of the methyl top is fairly large in syn-CH{sub 3}CHOO, implying a significant interaction between the terminal oxygen and the protons of the methyl moiety, which may be responsible for the high production yields of the OH radical from energized alkyl-substituted Criegee intermediates.
Authors:
;  [1]
  1. Department of Basic Science, Graduate School of Arts and Sciences, The University of Tokyo, 3-8-1 Komaba, Meguro-ku, Tokyo 153-8902 (Japan)
Publication Date:
OSTI Identifier:
22253658
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Chemical Physics; Journal Volume: 140; Journal Issue: 1; 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; FOURIER TRANSFORMATION; HYDROXYL RADICALS; INTERACTIONS; OXYGEN; PROTONS; ROTATION; SPECTROSCOPY