Direct Measurements of Conformer-Dependent Reactivity of the Criegee Intermediate CH3CHOO
Direct Measurements of Conformer-Dependent Reactivity of the Criegee Intermediate CH3CHOO
复制标题
DOI：
10.1126/science.1234689
复制
发表时间：
2013-04-12
期刊：
影响因子：
56.9
通讯作者：
Percival, Carl J.
中科院分区：
文献类型：
--
作者：
Taatjes, Craig A.;Welz, Oliver;Percival, Carl J.
虽然羰基氧化物，即“Criegee中间体”，长期以来一直与对流层氧化有关，但对其动力学的直接测量很少，而且只针对同类化合物中最简单的2oo。在这里，我们报道了下一个较大的Criegee中间体CH3CHOO的产生和反应动力学。此外，我们独立地探测了两种不同的CH3CHOO构象，顺-和反-，它们都很容易与SO2和NO2反应。我们证明了anti-CH3CHOO对水和SO2的反应性比syn-CH3CHOO强得多。与水的反应可能主导对流层中克里基中间体的去除，并决定其在大气中的浓度。得到了同- ch3choo与水反应的上限，测得反- ch3choo与水反应的速率常数为1.0 × 10(-14) +/- 0.4 × 10(-14) cm(3)秒（-1）。
Although carbonyl oxides, "Criegee intermediates," have long been implicated in tropospheric oxidation, there have been few direct measurements of their kinetics, and only for the simplest compound in the class, CH2OO. Here, we report production and reaction kinetics of the next larger Criegee intermediate, CH3CHOO. Moreover, we independently probed the two distinct CH3CHOO conformers, syn- and anti-, both of which react readily with SO2 and with NO2. We demonstrate that anti-CH3CHOO is substantially more reactive toward water and SO2 than is syn-CH3CHOO. Reaction with water may dominate tropospheric removal of Criegee intermediates and determine their atmospheric concentration. An upper limit is obtained for the reaction of syn-CH3CHOO with water, and the rate constant for reaction of anti-CH3CHOO with water is measured as 1.0 x 10(-14) +/- 0.4 x 10(-14) centimeter(3) second(-1).