在Criegee中间体和低酸之间的快速大气反应
Yu-Qiong Zhang1, Joseph S Francisco2, Bo Long1,3
1College of Physics and Mechatronic Engineering, Guizhou Minzu University, Guiyang 550025, China.
The journal of physical chemistry. A
|January 25, 2024
概括
克里奇的中间体与低酸 (HOCl) 迅速反应,显著影响HOCl的大气去除,特别是在夜间. 无和性强烈影响CH2OO反应,但对甲基替代的Criegee中间体的影响较小.
科学领域:
- 大气化学 大气化学
- 量子化学 是一个量子化学.
- 化学动力学 化学动力学
背景情况:
- 低酸 (HOCl) 对于大气氧化和臭氧消耗至关重要.
- 主要在白天通过光解和OH反应去除HOCl,夜间去除途径有限.
研究的目的:
- 研究Criegee中间体 (CH2OO,anti/syn-CH3CHOO) 和HOCl.之间的快速反应.
- 使用高级计算方法量化这些反应的速率常数.
- 评估这些反应在大气中HOCl去除中的作用,特别是在夜间.
主要方法:
- 为了准确性,采用了高级量子化学方法 (CCSDT ((Q) /CBS基准).
- 采用了双层策略,将传统和变化的过渡状态理论与小曲率道结合起来.
- 在温度范围 (190-350 K) 内的Criegee中间体+HOCl反应的计算速率常数.
主要成果:
- 克里基中间体与HOCl迅速反应,对HOCl在夜间沉没做出了重大贡献.
- 无性增加了CH2OO + HOCl速率常数的18-5.5倍.
- 无和性对抗/同-CH3CHOO + HOCl 反应有很小的影响;松散的过渡状态对抗-CH3CHOO 是速率决定性的.
结论:
- 克里吉中间体与HOCl的反应代表了HOCl的重要夜间去除途径.
- 在Criegee中间体中的甲基组替代影响反应性和无和性的影响.
- 准确的理论计算对于理解大气反应动力学和机制至关重要.
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