Zhang Yunju, Tang Yizhen, Sun Jingyu, He Bing
Key Laboratory of Photoinduced Functional Materials, Mianyang Normal University, Mianyang, 621000, People's Republic of China.
School of Environmental and Municipal Engineering, Qingdao University of Technology, Fushun Road 11, Qingdao, 266033, Shandong, People's Republic of China.
J Mol Model. 2020 May 15;26(6):139. doi: 10.1007/s00894-020-4318-7.
The reactions of the CHXO (X=F, Cl) with chlorine radical have been firstly investigated utilizing the BMC-CCSD//B3LYP method. The comprehensive calculations indicate that the association-elimination and S2 displacement reaction mechanisms existed on the singlet potential energy surface (PES), and H-abstraction and S2 displacement reaction mechanism existed on the triplet PES for the CHXO (X=F, Cl) + Cl reactions. On the triplet PES, the dominant reactions are production of P3 (CHXO (X=F, Cl) + HCl) by direct H-abstraction. On the singlet PES, three energy-rich adducts, IM1 (CHXOOCl (X=F, Cl)), IM2 (CHXOClO (X=F, Cl)), and IM3 (CH(OX)OCl (X=F, Cl)), are produced. RRKM-computed reveals that IM1 (CHXOOCl (X=F, Cl)) produced by collisional stabilization occupied the reaction T ≤ 500 and 400 K, respectively, while P1 (CHXO (X=F, Cl) + HOCl) are forecasted to be the dominant products at high temperatures. The atmospheric lifetime of CHFO and CHClO in Cl is around 1.18 and 2.50 weeks, respectively. Time-dependent density functional theory (TDDFT) computations imply that IM1 (CHXOOCl (X=F, Cl)) will photolyze under the sunlight. The current results could guide us to well understand the mechanism of the CHXO (X=F, Cl) + Cl reactions and may be helpful to understand Cl-combustion chemistry. Graphical Abstract Predicted rate constant of the dominant pathways and the total rate constants at 760 Torr, N2 in the temperature region of 200-3000 K for the CHXO (X=F, Cl) + Cl reactions.
首次利用BMC-CCSD//B3LYP方法研究了CHXO（X = F，Cl）与氯自由基的反应。综合计算表明，单重态势能面（PES）上存在缔合-消除和S2取代反应机理，而CHXO（X = F，Cl）+ Cl反应在三重态势能面上存在氢原子提取和S2取代反应机理。在三重态势能面上，主要反应是通过直接氢原子提取生成P3（CHXO（X = F，Cl）+ HCl）。在单重态势能面上，生成了三种能量丰富的加合物，即IM1（CHXOOCl（X = F，Cl））、IM2（CHXOClO（X = F，Cl））和IM3（CH(OX)OCl（X = F，Cl））。RRKM计算表明，碰撞稳定化产生的IM1（CHXOOCl（X = F，Cl））分别在反应温度T≤500 K和400 K时占主导，而P1（CHXO（X = F，Cl）+ HOCl）预计在高温下是主要产物。CHFO和CHClO在Cl中的大气寿命分别约为1.18周和2.50周。含时密度泛函理论（TDDFT）计算表明，IM1（CHXOOCl（X = F，Cl））在阳光下会发生光解。目前的结果可以指导我们更好地理解CHXO（X = F，Cl）+ Cl反应的机理，可能有助于理解氯燃烧化学。图形摘要CHXO（X = F，Cl）+ Cl反应在760 Torr、N2气氛下200 - 3000 K温度范围内主要路径的预测速率常数和总速率常数。
