作者:Björn Klotz、Ian Barnes、Karl H. Becker、Bernard T. Golding
DOI:10.1039/a606152d
日期:——
The atmospheric chemistry of benzene oxide/oxepin, a possible
intermediate in the atmospheric oxidation of aromatic hydrocarbons,
has been investigated in a large volume photoreactor at 298 K and
atmospheric pressure using in situ FTIR spectroscopy
for the analysis. Rate coefficients of
(10.0±0.4)×10
-11
and
(9.2±0.3)×10
-12
cm
3
molecule
-1
s
-1
have been determined for the
reaction of benzene oxide/oxepin with OH and NO
3
radicals,
respectively. Reaction with OH radicals produces almost exclusively
the (E,Z)- and (E,E)-isomers of
hexa-2,4-dienedial, whereas reaction with NO
3
produces
(Z,Z)-hexa-2,4-dienedial and unidentified organic
nitrates. Phenol has been observed as a major product of the thermal
decomposition, visible and UV photolysis of benzene oxide/oxepin. The
results are discussed in conjunction with the oxidation mechanisms of
aromatic hydrocarbons. The major atmospheric sinks of benzene
oxide/oxepin will be reaction with OH radicals and photolysis and,
under smog chamber conditions with high NO
2
concentrations,
also reaction with NO
3
.
苯氧化物/环氧庚烷的大气化学,作为芳香烃大气氧化可能的中间体,已在298K和大气压下使用现场傅里叶变换红外光谱进行分析的大型体积光反应器中进行了研究。发现苯氧化物/环氧庚烷与OH和NO3自由基反应的速率系数分别为(10.0±0.4)×10-11和(9.2±0.3)×10-12 cm3分子-1 s-1。与OH自由基反应几乎专门生成(E,Z)-和(E,E)-己二烯二醛异构体,而与NO3反应生成(Z,Z)-己二烯二醛和未识别的有机硝酸盐。作为苯氧化物/环氧庚烷热分解、可见光和紫外光解的主要产物,酚已被观察到。研究结果与芳香烃的氧化机理结合讨论。苯氧化物/环氧庚烷的主要大气汇将是与OH自由基的反应和光解,以及在NO2浓度高的烟雾室条件下,也与NO3的反应。