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Formation of ring‐retaining products from the OH radical‐initiated reactions of benzene and toluene
Author(s) -
Atkinson Roger,
Aschmann Sara M.,
Arey Janet,
Carter William P. L.
Publication year - 1989
Publication title -
international journal of chemical kinetics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.341
H-Index - 68
eISSN - 1097-4601
pISSN - 0538-8066
DOI - 10.1002/kin.550210907
Subject(s) - chemistry , toluene , benzene , nitrobenzene , radical , benzaldehyde , phenol , ring (chemistry) , medicinal chemistry , nitration , photochemistry , organic chemistry , catalysis
The aromatic ring‐retaining products formed from the gas–phase reactions of the OH radical with benzene and toluene, in the presence of NO x , have been identified and their formation yields determined. These products, and their formation yields, are as follows: from benzene – phenol, 0.236 ± 0.044; nitrobenzene, {(0.0336 ± 0.0078) + (3.07 ± 0.92) × 10 −16 [NO 2 ]}; from toluene – benzaldehyde, 0.0645 ± 0.0080; benzyl nitrate, 0.0084 ± 0.0017; o −cresol, 0.204 ± 0.027; m − + p −cresol, 0.048 ± 0.009; m ‐nitrotoluene, {(0.0135 ± 0.0029) + (1.90 ± 0.25) × 10 −16 [NO 2 ]}, where the NO 2 concentration is in molecule cm −3 units. The formation yields of o ‐ and p ‐nitrotoluene from toluene were ca. 0.07 and 0.35 that of m ‐nitrotoluene, respectively. The observations that the nitro‐aromatic yields do not extrapolate to zero as the NO 2 concentration approaches zero are not consistent with current chemical mechanisms for these OH radical‐initiated reactions, and suggest that under the experimental conditions employed in this study the hydroxycyclohexadienyl radicals formed from OH radical addition to the aromatic ring react with NO 2 rather than with O 2 . However, these data concerning the nitroaromatic yields are consistent with our previous conclusions that many of the nitrated polycyclic aromatic hydrocarbons present in ambient air are formed, at least in part, in the atmosphere from OH radical reactions.