Reaction rates of hydroxyl radical with nitric acid and with hydrogen peroxide
Reaction rates of hydroxyl radical with nitric acid and with hydrogen peroxide
复制标题
羟基自由基与硝酸和过氧化氢的反应速率
DOI：
10.1063/1.443998
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发表时间：
1982
影响因子：
4.4
通讯作者：
H. Johnston
中科院分区：
文献类型：
--
作者：
W. Marinelli;H. Johnston
通过反应物的激光闪光光解和羟基自由基的共振荧光研究了 HO+HNO3 → H2O+NO3, (1)、HO+H2O2 → H2O+HOO (2) 的反应速率。最近报道的两个反应在室温下的高速率常数和低温下反应（1）的负活化能已得到证实。这里获得的结果是：k1 = 1.52×10−14 exp(644/T) cm3 molecule−1 s−1 (218–363 K) 和 k2 = 1.81×10−12 cm3 molecule−1 s−1 (298 K)。这两个反应已通过过渡态理论进行了检验； (1) 被指定为循环状态，(2) 被指定为链状过渡状态。即使没有势垒，(1) 的反应坐标也涉及量子力学、与温度无关的频率；通过该模型可以解释反应（1）的低指前因子和负活化能。
The rates of the reactions HO+HNO3 → H2O+NO3, (1), HO+H2O2 → H2O+HOO (2) have been studied by laser flash photolysis of reactants and resonance fluorescence of hydroxyl radicals. The recently reported high rate constants at room temperature for both reactions and the negative activation energy for Reaction (1) at low temperature have been confirmed. Results obtained here are: k1 = 1.52×10−14 exp(644/T) cm3 molecule−1 s−1 from 218–363 K and k2 = 1.81×10−12 cm3 molecule−1 s−1 at 298 K. These two reactions have been examined by transition‐state theory; (1) is assigned a cyclic and (2) a chainlike transition state. Even with no potential energy barrier, the reaction coordinate of (1) involves a quantum‐mechanical, temperature independent frequency; and with this model the low pre‐exponential factor and negative activation energy of Reaction (1) can be explained.