克里吉中间体 (CH2OO) 与异构异环合物的温度和压力依赖动力学:理论研究
Amit Debnath1, Balla Rajakumar1
1Department of Chemistry, Indian Institute of Technology Madras, Chennai 600036, India.
The journal of physical chemistry. A
|August 1, 2025
概括
计算研究显示,Criegee中间体 (CH2OO) 和furaldehydes之间的反应很慢. 由于大气寿命长,这些反应不会显著影响大气中的甲水平.
科学领域:
- 大气化学 大气化学
- 化学动力学 化学动力学
- 计算化学的计算化学
背景情况:
- 克里奇中间体 (CH2OO) 是大气氧化过程中的关键物种.
- 甲是具有潜在大气相关性的挥发性有机化合物.
- 了解CH2OO与furaldehydes的反应性对于大气模型至关重要.
研究的目的:
- 为了研究CH2OO和2-furaldehyde/3-furaldehyde之间的反应的温度和压力依赖的动力学.
- 确定反应速率系数并确定主要的反应产物.
- 评估这些反应对甲度的大气影响.
主要方法:
- 使用B3LYP/6-311G+(2df,2p) 理论进行几何优化和热化学参数计算.
- 在CCSD(T) -F12b/cc-pVTZ-F12//B3LYP/6-311 + G(2df,2p) 层面进行屏障高度计算.
- 使用规范变量过渡状态理论与小曲率道 (CVT/SCT) 和MESMER计算速率系数.
主要成果:
- 对CH2OO + 2-furaldehyde和CH2OO + 3-furaldehyde的计算室温,高压限速系数分别为7.20 × 10−12和3.04 × 10−12 cm3分子−1 s−1.
- 在MESMER的计算中,比率系数略低:2.62 × 10−12和1.59 × 10−12 cm3分子−1 s−1.1.
- 已识别的产品包括酸,甲和碳酸;甲在大气中的寿命超过400天.
结论:
- 克里吉中间体与2-和3-甲的反应相对缓慢.
- 这些反应对化的空气净度的影响微不足道.
- 漫长的大气寿命表明甲在大气中存在,但它们通过CH2OO的去除并不是一个显著的沉.
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