FTIR spectroscopic studies of the mechanisms of the halogen atom initiated oxidation of haloacetaldehydes

Journal Article · Thu Apr 18 04:00:00 EDT 1996 · Journal of Physical Chemistry

DOI:https://doi.org/10.1021/jp953103q· OSTI ID:263157

Chen, J; Young, V; Catoire, V; Niki, Hiromi ^[1]

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1. York Univ., North York (Canada)

Product studies of Cl atom initiated oxidation of ClCH{sub 2}CHO and Br atom initiated oxidation of BrCH{sub 2}CHO were conducted by FTIR spectroscopy at 297 {+-} 2 K in 700 Torr of O{sub 2}/N{sub 2} diluent, using reactant partial pressures in both the torr and millitorr ranges. The halogen atoms initiate reaction via hydrogen abstraction from the aldehydic group (CHO), producing haloacetyl radicals, XCH{sub 2}CO, where X = Cl or Br. In 700 Torr of air, the XCH{sub 2}CO radicals may react via three channels: (i) O{sub 2}-addition, (ii) unimolecular dissociation by C-C bond cleavage, and (iii) unimolecular dissociation by C-X bond cleavage. All three channels were observed for BRCH{sub 2}CO radicals, enabling estimation of the branching ratios, but ClCH{sub 2}CO reacts only by O{sub 2}-addition. Subsequent reactions of XCH{sub 2}C(O)O{sub 2} radicals lead to XCH{sub 2}O radical and CO{sub 2} formation. The ClCH{sub 2}O radical reacts with O{sub 2} to produce CHClO and HO{sub 2}, while the BrCH{sub 2}O radical mainly eliminates the Br atom, based on CH{sub 2}O detected. 28 refs., 6 figs., 3 tabs.

• OSTI ID: 263157
• Journal Information: Journal of Physical Chemistry, Journal Name: Journal of Physical Chemistry Journal Issue: 16 Vol. 100; ISSN JPCHAX; ISSN 0022-3654
• Country of Publication: United States
• Language: English

Related Subjects

40 CHEMISTRY
ALDEHYDES
ATMOSPHERIC CHEMISTRY
BRANCHING RATIO
BROMINE
CHLORINE
DISSOCIATION
HALOGEN COMPOUNDS
INFRARED SPECTRA
MOLECULES
OXIDATION
RADICALS