Kinetic investigation of the OH radical and Cl atom initiated degradation of unsaturated ketones at atmospheric pressure and 298 K.
Kinetic investigation of the OH radical and Cl atom initiated degradation of unsaturated ketones at atmospheric pressure and 298 K.
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DOI：
10.1021/jp2109972
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发表时间：
2012-02
期刊：
影响因子：
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通讯作者：
M. B. Blanco;I. Barnes;P. Wiesen
中科院分区：
文献类型：
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作者：
M. B. Blanco;I. Barnes;P. Wiesen
在298 ± 2K和大气压下测定了羟基自由基和氯原子与4-己烯-3-酮、5-己烯-2-酮和3-戊烯-2-酮反应的速率系数。速率系数的化合物使用相对动力学技术与不同的参考化合物。实验在一个大型光反应器（480 L）中进行，使用原位FTIR光谱监测反应物的衰变。根据不同的测量结果，（单位cm（3）分子（-1）s（-1））：（1）（OH + 4-己烯-3-酮）=（9.04 ± 2.12）× 10（-11），k（2）（OH + 5-己烯-2-酮）=（5.18 ± 1.27）× 10（-11），k（3）（OH + 3-戊烯-2-酮）=（7.22 ± 1.74）× 10（-11），k（4）（Cl + 4-己烯-3-酮）=（3.00 ± 0.58）× 10 - 10，k（5）（Cl + 5-己烯-2-酮）=（3.15 ± 0.50）× 10 - 10，k（6）（Cl + 3-戊烯-2-酮）=（2.53 ± 0.54）× 10 - 10。比较和讨论了烯烃和不饱和酮中双键在298 K时对OH自由基和Cl原子的加成反应。此外，不饱和酮对OH自由基的反应性和化合物的HOMO之间的相关性。在动力学测量的基础上，4-己烯-3-酮、5-己烯-2-酮和3-戊烯-2-酮与羟基自由基反应的对流层寿命估计为2 - 3 h。
Rate coefficients for the reactions of hydroxyl radicals and chlorine atoms with 4-hexen-3-one, 5-hexen-2-one, and 3-penten-2-one have been determined at 298 ± 2 K and atmospheric pressure of air. Rate coefficients for the compounds were determined using a relative kinetic technique with different reference compounds. The experiments were performed in a large photoreactor (480 L) using in situ FTIR spectroscopy to monitor the decay of reactants. From the different measurements the following rate coefficients (in units of cm(3) molecule(-1) s(-1)) have been determined: k(1)(OH + 4-hexen-3-one) = (9.04 ± 2.12) × 10(-11), k(2)(OH + 5-hexen-2-one) = (5.18 ± 1.27) × 10(-11), k(3)(OH + 3-penten-2-one) = (7.22 ± 1.74) × 10(-11), k(4)(Cl + 4-hexen-3-one) = (3.00 ± 0.58) × 10(-10), k(5)(Cl + 5-hexen-2-one) = (3.15 ± 0.50) × 10(-10) and k(6)(Cl + 3-penten-2-one) = (2.53 ± 0.54) × 10(-10). The reactivity of the double bond in alkenes and unsaturated ketones at 298 K toward addition of OH radicals and Cl atoms are compared and discussed. In addition, a correlation between the reactivity of the unsaturated ketones toward OH radicals and the HOMO of the compounds is presented. On the basis of the kinetic measurements, the tropospheric lifetimes of 4-hexen-3-one, 5-hexen-2-one, and 3-penten-2-one with respect to their reaction with hydroxyl radicals are estimated to be between 2 and 3 h.