Kinetics of Hydroxyl Radical Reactions with Isotopically Labeled Hydrogen
Kinetics of Hydroxyl Radical Reactions with Isotopically Labeled Hydrogen
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DOI：
10.1021/jp9518724
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发表时间：
1996-02
期刊：
影响因子：
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通讯作者：
R. Talukdar;T. Gierczak;Leah Goldfarb;Y. Rudich;and B. K. Rao;A. Ravishankara
中科院分区：
文献类型：
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作者：
R. Talukdar;T. Gierczak;Leah Goldfarb;Y. Rudich;and B. K. Rao;A. Ravishankara
羟基自由基（OH）与H2 （k1）、HD （k2）和D2 （k3）的反应速率系数在~ 230和~ 420 K之间测量为k1= 7.21 × 10-20T2.69 exp(−1150/T), k2 = 5.57 × 10-20T2.7 exp(−1258/T), k3 = 5.7 × 10-20T2.73 exp(−1580/T) cm3分子-1 s-1，使用脉冲光解产生OH并激光诱导荧光检测。用同样的方法测得OD与H2和D2的反应速率系数分别为k1和k3。在反应2中，用CW Lyman-α共振荧光检测，在250和298 K下，H的产率分别为0.17±0.03和0.26±0.05。在本研究的整个温度范围内，K2是k1和k3之和的一半。所引用的不确定性在95%的置信水平，并包括估计的系统误差。在这些发现的基础上，我们提出，在这里研究的温度范围内，大多数（如果不是全部的话）反应可能是通过H/D隧穿发生的。
The rate coefficients for the reactions of hydroxyl radical (OH) with H2 (k1), HD (k2), and D2 (k3) were measured between ∼230 and ∼420 K to be k1= 7.21 × 10-20T2.69 exp(−1150/T), k2 = 5.57 × 10-20T2.7 exp(−1258/T), and k3 = 5.7 × 10-20T2.73 exp(−1580/T) cm3 molecule-1 s-1 using pulsed photolysis to generate OH and laser-induced fluorescence to detect it. Using the same method, the rate coefficients for the reactions of OD with H2 and D2 were measured to be equal to k1 and k3, respectively. In reaction 2, the yield of H was measured to be 0.17 ± 0.03 and 0.26 ± 0.05 at 250 and 298 K, respectively, by detecting it using CW Lyman-α resonance fluorescence. k2 was found to be half the sum of k1 and k3 over the entire temperature range of this study. The quoted uncertainties are at the 95% confidence level and include estimated systematic errors. On the basis of these findings it is suggested that most, if not all, of the reaction in the range of temperatures studied here may be occurring via tunneling of H/D ...