On the importance of prereactive complexes in molecule-radical reactions: Hydrogen abstraction from aldehydes by OH
On the importance of prereactive complexes in molecule-radical reactions: Hydrogen abstraction from aldehydes by OH
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DOI：
10.1021/ja003372g
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发表时间：
2001-03-07
影响因子：
15
通讯作者：
Vivier-Bunge, A
中科院分区：
文献类型：
--
作者：
Alvarez-Idaboy, JR;Mora-Diez, N;Vivier-Bunge, A
在这项工作中，OH + 甲醛和 OH + 乙醛反应已使用精确的从头计算方法和大基组进行了表征。结果清楚地表明该反应是通过夺氢发生的，并且OH加成通道是不利的。获得接近零（对于甲醛）和负（对于乙醛）的活化能值，这与实验观察到的值非常一致。使用经典过渡态理论计算的反应速率常数应用于涉及预反应复合物形成的复杂机制，很好地再现了报告的实验结果。事实证明，考虑预反应复合物对于确定能垒高度至关重要，因此对于正确确定能垒高度至关重要；计算你的隧道因子。
In this work, the OH + formaldehyde and OH + acetaldehyde reactions have been characterized using accurate ab initio methods with, large basis sets. The results clearly indicate that the reaction occurs by hydrogen abstraction, and that the OH addition channel is unfavorable. Close to zero (for formaldehyde) and negative (for acetaldehyde) activation energy values are obtained, which are in excellent agreement with the experimentally observed values. The reaction rate constants, calculated using the classical transition-state theory as applied to a complex mechanism involving the formation of a prereactive complex, reproduce very well the reported experimental results. Consideration of the prereactive complex is shown to be essential for the determination of the height of the energy barrier and thus for the correct; calculation of thy tunneling factor.