Yang Zhenli, Lin Xiaoxiao, Zhou Jiacheng, Hu Mingfeng, Gai Yanbo, Zhao Weixiong, Long Bo, Zhang Weijun
Laboratory of Atmospheric Physico-Chemistry, Anhui Institute of Optics and Fine Mechanics, Chinese Academy of Sciences Hefei 230031 Anhui China
University of Science and Technology of China Hefei 230026 China.
RSC Adv. 2019 Dec 6;9(69):40437-40444. doi: 10.1039/c9ra07503h. eCollection 2019 Dec 3.
The -propyl peroxy radical (-CHO) is the key intermediate during atmospheric oxidation of propane (CH) which plays an important role in the carbon and nitrogen cycles in the troposphere. In this paper, a comprehensive theoretical study on the reaction mechanism and kinetics of the reaction between HO and -CHO was performed at the CCSD(T)/aug-cc-pVDZ//B3LYP/6-311G(d,p) level of theory. Computational results show that the HO + -CHO reaction proceeds on both singlet and triplet potential energy surfaces (PESs). From an energetic point of view, the formation of CHOH and O triplet hydrogen abstraction is the most favorable channel while other product channels are negligible. In addition, the calculated rate constants for the title reaction over the temperature range of 238-398 K were calculated by the multiconformer transition state theory (MC-TST), and the calculated rate constants show a negative temperature dependence. The contributions of the other four reaction channels to the total rate constant are negligible.
丙基过氧自由基（-CHO）是丙烷（CH）大气氧化过程中的关键中间体，在对流层的碳和氮循环中起着重要作用。本文在CCSD(T)/aug-cc-pVDZ//B3LYP/6-311G(d,p)理论水平上对HO与-CHO反应的机理和动力学进行了全面的理论研究。计算结果表明，HO + -CHO反应在单重态和三重态势能面（PESs）上均能进行。从能量角度来看，生成CHOH和O的三重态氢提取是最有利的通道，而其他产物通道可忽略不计。此外，通过多构象过渡态理论（MC-TST）计算了标题反应在238 - 398 K温度范围内的速率常数，计算得到的速率常数呈现负温度依赖性。其他四个反应通道对总速率常数的贡献可忽略不计。
