Rate Constants for the Reactions of OH Radical with the ( E)/( Z) Isomers of CF3CF═CHCl and CHF2CF═CHCl.
Rate Constants for the Reactions of OH Radical with the ( E)/( Z) Isomers of CF3CF═CHCl and CHF2CF═CHCl.
复制标题
OH 自由基与 CF3CF=CHCl 和 CHF2CF=CHCl 的 (E)/(Z) 异构体的反应速率常数。
DOI：
10.1021/acs.jpca.7b11923
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发表时间：
2018
影响因子：
2.9
通讯作者：
S. Kondo
中科院分区：
文献类型：
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作者：
K. Tokuhashi;T. Uchimaru;K. Takizawa;S. Kondo
在250-430K温度范围内，测定了OH自由基与CF3CF═CHCl和CHF2CF═CHCl的(E)和(Z)异构体反应的速率常数。用闪光和激光光解结合激光诱导荧光的方法进行了动力学测定。阿累尼乌斯速率常数k((E)-CF3CF═CHCl)=(1.0 9±0.0 3)×10-12·EXP[(5 0±10)K/T]，k((Z)-CF3CF═CHCl)=(8.0 2±0.19)×10-13·EXP[-(10 0±10)K/T]，k((E)-CHF2CF═CHCl)=(1.5 0±0.0 3)×10-12·EXP[(16 0±10)K/T]，K((Z)-CHF_2CF═CHCl)=(1.3 6±0.0 3)×10-12·exp[(36 0±10)K/T]cm~3分子-1 S还测量了室温下的红外吸收光谱。(E)-CF3CF═CHCl、(Z)-CF3CF═CHCl、(E)-CHF2CF═CHCl和(Z)-CHF2CF═CHCl的大气寿命分别为8.9d、20d、4.6d和2.6d，其全球变暖潜势和臭氧消耗潜势分别为0.23、0.88、0.060和0.016和0.00010、0.00023、0.000057和0.000030。此外，还计算了这些化合物的羟基自由基加成反应速率常数和红外光谱。与实验一致，我们的计算表明，对OH自由基加成的反应性为(Z)-CHF2CF═CHCl>；(E)-CHF2CF═CHCl>；(E)-CF3CF═CHCl>；(Z)-CF3CF═CHCl；(Z)-CF3CF═CHCl和CHF2CF═CHCl的反应性相反。计算结果重现了观测到的OH自由基反应速率常数的温度依赖关系，对于(Z)-CF3CF═CHCl略为正，而对其他化合物为负。
The rate constants for the reactions of OH radical with ( E)- and ( Z)-isomers of CF3CF═CHCl and CHF2CF═CHCl have been measured over the temperature range of 250-430 K. Kinetic measurements have been performed using flash and laser photolysis methods combined with laser-induced fluorescence. Arrhenius rate constants have been determined as k(( E)-CF3CF═CHCl) = (1.09 ± 0.03) × 10-12 · exp[(50 ± 10)K/ T], k(( Z)-CF3CF═CHCl) = (8.02 ± 0.19) × 10-13 · exp[-(100 ± 10)K/ T], k(( E)-CHF2CF═CHCl) = (1.50 ± 0.03) × 10-12 · exp[(160 ± 10)K/ T], and k(( Z)-CHF2CF═CHCl) = (1.36 ± 0.03) × 10-12 · exp[(360 ± 10)K/ T] cm3 molecule-1 s-1. Infrared absorption spectra have also been measured at room temperature. The atmospheric lifetimes of ( E)-CF3CF═CHCl, ( Z)-CF3CF═CHCl, ( E)-CHF2CF═CHCl, and ( Z)-CHF2CF═CHCl have been estimated as 8.9, 20, 4.6, and 2.6 days, respectively, and their global warming potentials and ozone depletion potentials were determined as 0.23, 0.88, 0.060, and 0.016 and 0.00010, 0.00023, 0.000057, and 0.000030, respectively. Additionally, the rate constants for OH radical addition and IR spectra of these compounds were determined computationally. Consistent with experiment, our calculations indicate that the reactivity toward OH radical addition is reduced as ( Z)-CHF2CF═CHCl > ( E)-CHF2CF═CHCl > ( E)-CF3CF═CHCl > ( Z)-CF3CF═CHCl, where the ( E)/( Z) reactivity is reversed for CF3CF═CHCl and CHF2CF═CHCl. The calculations reproduced the observed temperature dependencies of the rate constants for the OH radical reactions, which is slightly positive for ( Z)-CF3CF═CHCl but negative for the other compounds.