Gierczak Tomasz, Baasandorj M, Burkholder James B
Earth System Research Laboratory, Chemical Sciences Division, National Oceanic and Atmospheric Administration, 325 Broadway, Boulder Colorado 80305, United States.
J Phys Chem A. 2014 Nov 20;118(46):11015-25. doi: 10.1021/jp509127h. Epub 2014 Nov 6.
Rate coefficients for the gas-phase reaction of the OH radical with (E)- and (Z)-CF3CH═CHCl (1-chloro-3,3,3-trifluoropropene-1, HFO-1233zd) (k1(T) and k2(T), respectively) were measured under pseudo-first-order conditions in OH over the temperature range 213-376 K. OH was produced by pulsed laser photolysis, and its temporal profile was measured using laser-induced fluorescence. The obtained rate coefficients were independent of pressure between 25 and 100 Torr (He, N2) with k1(296 K) = (3.76 ± 0.35) × 10(-13) cm(3) molecule(-1) s(-1) and k2(296 K) = (9.46 ± 0.85) × 10(-13) cm(3) molecule(-1) s(-1) (quoted uncertainties are 2σ and include estimated systematic errors). k2(T) showed a weak non-Arrhenius behavior over this temperature range. The (E)- and (Z)- stereoisomer rate coefficients were found to have opposite temperature dependencies that are well represented by k1(T) = (1.14 ± 0.15) × 10(-12) exp[(-330 ± 10)/T] cm(3) molecule(-1) s(-1) and k2(T) = (7.22 ± 0.65) × 10(-19) × T(2) × exp[(800 ± 20)/T] cm(3) molecule(-1) s(-1). The present results are compared with a previous room temperature relative rate coefficient study of k1, and an explanation for the discrepancy is presented. CF3CHO, HC(O)Cl, and CF3CClO, were observed as stable end-products following the OH radical initiated degradation of (E)- and (Z)-CF3CH═CHCl in the presence of O2. In addition, chemically activated isomerization was also observed. Atmospheric local lifetimes of (E)- and (Z)-CF3CH═CHCl, due to OH reactive loss, were estimated to be ∼34 and ∼11 days, respectively. Infrared absorption spectra measured in this work were used to estimate radiative efficiencies and well-mixed global warming potentials of ∼10 and ∼3 for (E)- and (Z)-CF3CH═CHCl, respectively, on the 100-year time horizon.
在213 - 376 K的温度范围内，在OH的准一级条件下测量了OH自由基与（E）-和（Z）-CF3CH═CHCl（1-氯-3,3,3-三氟丙烯-1，HFO-1233zd）的气相反应速率系数（分别为k1(T)和k2(T)）。OH由脉冲激光光解产生，其时间分布通过激光诱导荧光进行测量。在25至100 Torr（He，N2）的压力范围内，获得的速率系数与压力无关，k1(296 K) = (3.76 ± 0.35) × 10(-13) cm(3) molecule(-1) s(-1)，k2(296 K) = (9.46 ± 0.85) × 10(-13) cm(3) molecule(-1) s(-1)（引用的不确定度为2σ，包括估计的系统误差）。在该温度范围内，k2(T)表现出微弱的非阿伦尼乌斯行为。发现（E）-和（Z）-立体异构体的速率系数具有相反的温度依赖性，可用k1(T) = (1.14 ± 0.15) × 10(-12) exp[(-330 ± 10)/T] cm(3) molecule(-1) s(-1)和k2(T) = (7.22 ± 0.65) × 10(-19) × T(2) × exp[(800 ± 20)/T] cm(3) molecule(-1) s(-1)很好地表示。将本研究结果与先前关于k1的室温相对速率系数研究进行了比较，并对差异给出了解释。在O2存在下，OH自由基引发（E）-和（Z）-CF3CH═CHCl降解后，观察到CF3CHO、HC(O)Cl和CF3CClO为稳定的最终产物。此外，还观察到化学活化异构化。由于OH反应性损失，（E）-和（Z）-CF3CH═CHCl在大气中的局部寿命估计分别约为34天和约11天。在这项工作中测量的红外吸收光谱用于估计（E）-和（Z）-CF3CH═CHCl在100年时间尺度上的辐射效率和混合良好的全球变暖潜能值，分别约为10和约3。
