在Criegee中介-Hydroperoxyl激素化学中的机械洞察
Bai Li1, Manoj Kumar2, Chuan Zhou1
1Department of Materials Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China.
Journal of the American Chemical Society
|August 3, 2022
概括
克里吉介质与基基 (HO2) 之间的反应是热层新粒子形成的关键. 水可以阻碍这种反应,这表明HO2和水在大气化学中的复杂作用.
科学领域:
- 大气化学
- 化学动力学
- 计算化学
背景情况:
- 在大气中的新粒子形成中, 克里奇介质是至关重要的.
- 克里吉介质与基基 (HO2) 之间的反应是一个重要的,但尚未完全理解的,大气过程.
- 之前的研究集中在气相反应上, 留下了关于反应机制和水的影响的知识空白.
研究的目的:
- 研究Criegee中间体 (anti-CH3CHOO) 和气相中的基基 (HO2) 的反应机制.
- 阐明水分子在反应系统中的作用.
- 在不同温度下定量确定这些反应的自由能量障碍.
主要方法:
- 使用计算化学方法对0K的反应进行模拟.
- 用于确认反应机制的元动力学模拟.
- 限制*ab initio*分子动力学与热力学集成相结合,以计算高温下的自由能量障碍.
主要成果:
- 反应是通过质子转移机制进行的,而不是以前假设的原子转移.
- 包含水的系统表现出低阻碍性,而无水的系统在0K时没有阻碍性.
- 自由能量障碍取决于温度,并且发现水阻碍了Criegee-HO2反应.
- 证实了激素添加物形成和HO2/H2O介导反应的协调机制.
结论:
- 水基 (HO2) 在气相中介于克里吉水化反应.
- 水分子可以阻碍Criegee中间体和HO2基之间的反应.
- 这些发现突显了HO2激素和水在热层新粒子形成中的复杂相互作用.
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