Atmospheric oxidation of vinyl and allyl acetate: product distribution and mechanisms of the OH-initiated degradation in the presence and absence of NO(x).
Atmospheric oxidation of vinyl and allyl acetate: product distribution and mechanisms of the OH-initiated degradation in the presence and absence of NO(x).
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DOI：
10.1021/es3015869
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发表时间：
2012-07
影响因子：
11.4
通讯作者：
M. B. Blanco;I. Bejan;I. Barnes;P. Wiesen;M. Teruel
中科院分区：
文献类型：
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作者：
M. B. Blanco;I. Bejan;I. Barnes;P. Wiesen;M. Teruel
OH自由基与乙酸乙烯酯和乙酸烯丙酯的反应形成的产品已在1080 L石英玻璃室中的存在和不存在的NO（x）使用原位FTIR光谱监测反应物的衰变和产物的形成进行了研究。OH与乙酸乙烯酯反应生成的初级产物产率分别为：甲酸乙酸酐（84 ± 11）%，有NO（x）存在时乙酸（18 ± 3）%，甲醛（99 ± 15）%，甲酸乙酸酐（28 ± 5）%，无NO（x）存在时乙酸（87 ± 12）%，甲醛（52 ± 8）%。OH与乙酸烯丙酯的反应，在NO（x）存在下，产物的产率分别为：乙酰氧基乙醛（96 ± 15）%和甲醛（90 ± 12）%;在NO（x）不存在下，产物的产率分别为：乙酰氧基乙醛（26 ± 4）%和甲醛（12 ± 3）%。目前的结果表明，在不存在NO（x）的情况下，在化合物中双键上加成OH后形成的1，2-羟基烷氧基自由基的主要归宿是，在乙酸乙烯酯的情况下，α-酯重排生成乙酸和CH（2）（OH）CO（·）自由基，在乙酸烯丙酯的情况下，自由基与O（2）反应生成乙酸3-羟基-2-氧代-丙酯（CH（3）C（O）OCH（2）C（O）CH（2）OH）。相反，在NO（x）的存在下，1，2-羟基烷氧基自由基的主要反应途径是分解。结果与现有的文献数据和乙烯基和烯丙基乙酸酯的大气化学的影响进行了比较评估。
The products formed from the reactions of OH radicals with vinyl acetate and allyl acetate have been studied in a 1080 L quartz-glass chamber in the presence and absence of NO(x) using in situ FTIR spectroscopy to monitor the reactant decay and product formation. The yields of the primary products formed in the reaction of OH with vinyl acetate were: formic acetic anhydride (84 ± 11)%; acetic acid (18 ± 3)% and formaldehyde (99 ± 15)% in the presence of NO(x) and formic acetic anhydride (28 ± 5)%; acetic acid (87 ± 12)% and formaldehyde (52 ± 8)% in the absence of NO(x). For the reaction of OH with allyl acetate the yields of the identified products were: acetoxyacetaldehyde (96 ± 15)% and formaldehyde (90 ± 12)% in the presence of NO(x) and acetoxyacetaldehyde (26 ± 4)% and formaldehyde (12 ± 3)% in the absence of NO(x). The present results indicate that in the absence of NO(x) the main fate of the 1,2-hydroxyalkoxy radicals formed after addition of OH to the double bond in the compounds is, in the case of vinyl acetate, an α-ester rearrangement to produce acetic acid and CH(2)(OH)CO(•) radicals and in the case of allyl acetate reaction of the radical with O(2) to form acetic acid 3-hydroxy-2-oxo-propyl ester (CH(3)C(O)OCH(2)C(O)CH(2)OH). In contrast, in the presence of NO(x) the main reaction pathway for the 1,2-hydroxyalkoxy radicals is decomposition. The results are compared with the available literature data and implications for the atmospheric chemistry of vinyl and allyl acetate are assessed.