Zhang Yu-Qiong, Xia Yu, Long Bo
College of Mechanical and Electrical Engineering, Guizhou Minzu University, Guiyang 550025, China.
College of Materials Science and Engineering, Guizhou Minzu university, Guiyang 550025, China.
Phys Chem Chem Phys. 2022 Oct 19;24(40):24759-24766. doi: 10.1039/d2cp02849b.
Obtaining quantitative kinetics of Criegee intermediates is of paramount significance in the atmosphere. However, there are limited reports on the kinetics of Criegee intermediates. Here, by using our very recently developed dual-level strategy, we report the quantitative kinetics of the reaction of Criegee intermediates (CHOO/-CHCHOO/-CHCHOO) with acetonitrile (CHCN). The dual-level strategy combines post-CCSD(T) calculations for transition state theory with the validated M06CR/MG3S and M11-L/MG3S functional methods for direct dynamics calculations using canonical variational transition state theory with small-curvature tunneling to obtain recrossing effects and tunneling coefficients. We show that W3X-L//DF-CCSD(T)-F12b/jun-cc-pVDZ can be used to obtain quantitative enthalpies of activation at 0 K in the reactions of Criegee intermediates with CHCN. We find that the CHOO/-CHCHOO/-CHCHOO + CHCN reactions only depend on temperature. Moreover, we also find that their rate constants are dominantly determined by the enthalpy of activation at 0 K and recrossing effects and tunneling are negligible. The present findings also show that the CHOO/-CHCHOO + CHCN reactions have negative temperature dependence in the range of 190-350 K. In the atmosphere, we reveal that the reactions of CHOO and -CHCHOO with CHCN are significant acetonitrile sinks, leading to the formation of -formylacetamide and diacetamide. The present findings will be useful for obtaining quantitative kinetics of Criegee intermediates and understanding acetonitrile sinks.
获取大气中Criegee中间体的定量动力学至关重要。然而，关于Criegee中间体动力学的报道有限。在此，我们利用最近开发的双水平策略，报告了Criegee中间体（CHOO/-CHCHOO/-CHCHOO）与乙腈（CHCN）反应的定量动力学。双水平策略将用于过渡态理论的后CCSD(T)计算与经过验证的M06CR/MG3S和M11-L/MG3S泛函方法相结合，采用具有小曲率隧道效应的正则变分过渡态理论进行直接动力学计算，以获得再穿越效应和隧道系数。我们表明，W3X-L//DF-CCSD(T)-F12b/jun-cc-pVDZ可用于获得Criegee中间体与CHCN反应在0 K时的定量活化焓。我们发现CHOO/-CHCHOO/-CHCHOO + CHCN反应仅取决于温度。此外，我们还发现它们的速率常数主要由0 K时的活化焓决定，再穿越效应和隧道效应可忽略不计。目前的研究结果还表明，CHOO/-CHCHOO + CHCN反应在190 - 350 K范围内具有负温度依赖性。在大气中，我们揭示了CHOO和-CHCHOO与CHCN的反应是重要的乙腈汇，导致甲酰乙酰胺和二乙酰胺的形成。目前的研究结果将有助于获得Criegee中间体的定量动力学并理解乙腈汇。
