College of Chemistry and Chemical Engineering and Jiangsu Key Laboratory of Green Synthetic Chemistry for Functional Materials, Jiangsu Normal University, Xuzhou, Jiangsu 221116, People's Republic of China.
J Phys Chem A. 2013 Aug 8;117(31):6883-92. doi: 10.1021/jp405687c. Epub 2013 Jul 24.
In this study, the reaction mechanism and kinetics of the hydrogen abstraction and addition reactions of NCO with HCHO in the absence and presence of water have been investigated theoretically for the first time. Our theoretical results indicate that direct hydrogen abstraction is favored in the formation of HNCO instead of HOCN and the addition pathways are negligible with and without water. The rate constants calculated at the CCSD(T)/aug-cc-pVTZ//BH&HLYP/6-311++G(3df,3pd) level with zero-point energy correction range from 1.60 × 10(-12) to 4.99 × 10(-12) cm(3) molecule(-1) s(-1) between 220 and 769 K without water and are in good agreement with the available experimental values. However, with the inclusion of water, the rate constants are slower by 2-8 orders of magnitude than those of the reaction without water. Accordingly, the effect of water on the reaction of NCO with HCHO is negligible in the atmosphere.
在这项研究中，首次从理论上研究了 NCO 与 HCHO 在无水和有水条件下的氢抽提和加成反应的反应机理和动力学。我们的理论结果表明，在 HNCO 的形成中，直接氢抽提是有利的，而不是 HOCN，并且在有水和无水的情况下，加成途径可以忽略不计。在 CCSD(T)/aug-cc-pVTZ//BH&HLYP/6-311++G(3df,3pd)水平上计算的带有零点能修正的速率常数在 220 到 769 K 之间的范围为 1.60×10(-12)到 4.99×10(-12)cm(3)分子(-1)s(-1)，在无水条件下与可用的实验值吻合良好。然而，加入水后，反应速率常数比无水条件下慢 2-8 个数量级。因此，水对 NCO 与 HCHO 反应的影响在大气中可以忽略不计。
