C3H2环丙烯基自由基与O(3P)反应机理的理论研究

本文用量子化学密度泛函方法对C3H2 (环丙烯基自由基)与O(3P)反应的机理进行了理论研究。在B3LYP/6-311++G**计算水平上优化了各驻点（过渡态，中间体，产物）的几何结构，在QCISD(T)/6-311++G**水平下计算了各物质的单点能量，在两种水平下计算了298K和600K时的能量。计算结果表明：C3H2 + O(3P) 反应可以生成P1 (C2H +HCO)，P2 (C2H2 + CO) 和P3 (HC3O+H)三种产物。生成P1反应通道的能垒最低，即P1为主要产物，与实验的结果一致。产物P1可以通过路径：R→ IM1→ IM2→ P1获得。本文详细地讨论了C3H2 + O(3P) 的反应机理，并从理论上对实验结果进行了验证。研究结果有助于深入理解C3H2 + O(3P)反应机理以及C3H2在大气中的燃烧过程。

Theoretical Studies on the Reaction Mechanisms of C3H2 (cyclopropenylidene) and O(3P) Radicals

The complex potential energy surface for the reaction of C₃H₂ (cyclopropenylidene) with O(³P) was explored computationally using a density functional and ab initio QCISD(T) methods. The geometries of all the stationary points (transition states, intermediates and products) were fully optimized at the B3LYP/6‐311++G???? computational level, and the single point calculation including full population analysis was performed by employing QCISD(T). Our results show that the product P1 (C₂H+HCO) is the major product, while the products P2 (C₂H₂+CO) and P3 (HC₃O+H) are minor products, as confirmed by experiment. Product P1 could be gained through the path: R → IM1 → IM2 → P1 , and the C₃H₂+O(³P) reaction was expected to be rapid. So, the C₃H₂+O(³P) reaction may be an efficient strategy for producing C₂H using cyclopropenylidene in atmosphere. The present results can lead us to understand deeply the mechanism of the title reaction.