標題: Infrared identification of the Criegee intermediates syn- and anti-CH3CHOO, and their distinct conformation-dependent reactivity
作者: Lin, Hui-Yu
Huang, Yu-Hsuan
Wang, Xiaohong
Bowman, Joel M.
Nishimura, Yoshifumi
Witek, Henryk A.
Lee, Yuan-Pern
應用化學系
應用化學系分子科學碩博班
Department of Applied Chemistry
Institute of Molecular science
公開日期: 1-五月-2015
摘要: The Criegee intermediates are carbonyl oxides that play critical roles in ozonolysis of alkenes in the atmosphere. So far, the mid-infrared spectrum of only the simplest Criegee intermediate CH2OO has been reported. Methyl substitution of CH2OO produces two conformers of CH3CHOO and consequently complicates the infrared spectrum. Here we report the transient infrared spectrum of syn- and anti-CH3CHOO, produced from CH3CHI + O-2 in a flow reactor, using a step-scan Fourier-transform spectrometer. Guided and supported by high-level full-dimensional quantum calculations, rotational contours of the four observed bands are simulated successfully and provide definitive identification of both conformers. Furthermore, anti-CH3CHOO shows a reactivity greater than syn-CH3CHOO towards NO/NO2; at the later period of reaction, the spectrum can be simulated with only syn-CH3CHOO. Without NO/NO2, anti-CH3CHOO also decays much faster than syn-CH3CHOO. The direct infrared detection of syn-and anti-CH3CHOO should prove useful for field measurements and laboratory investigations of the Criegee mechanism.
URI: http://dx.doi.org/10.1038/ncomms8012
http://hdl.handle.net/11536/124828
ISSN: 2041-1723
DOI: 10.1038/ncomms8012
期刊: NATURE COMMUNICATIONS
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