水电荷转移加速与水界面上的H2O基离子的Criegee中间反应
Qiujiang Liang1, Chongqin Zhu2, Jun Yang1
1Department of Chemistry, The University of Hong Kong, Hong Kong SAR, People's Republic of China.
Journal of the American Chemical Society
|April 3, 2023
概括
由于电荷转移,Criegee中间体 (CI) 在接口上与水反应更快,形成加速反应的基因对. 这一发现影响了大气化学和热层的氧化能力.
科学领域:
- 大气化学
- 化学动力学
- 计算化学
背景情况:
- 克里基中间体 (CI) 是影响气候的关键大气氧化剂.
- 与水的CI反应对热层化学至关重要.
- 在水面上CIs的界面反应性仍然不太清楚.
研究的目的:
- 研究Criegee与水之间的介面反应背后的分子机制.
- 阐明水电荷转移在空气/水接口加速CI-水反应中的作用.
- 了解接口效应如何影响CI的大气命运.
主要方法:
- 使用量子力学/分子力学 (QM/MM) 波恩-奥本海默分子动力学.
- 在计算中使用了局部二次摩勒-普莱塞特扰动理论.
- 分析分子动力学轨迹以确定反应途径和中间体.
主要成果:
- 在接口上观察到显著的水电荷转移 (高达20%),形成H2O+/H2O-激素对.
- 由于对H2O的静电吸引,CH2OO和抗CH3CHOO与水的反应性得到了增强.
- 在空气/水界面发现了一种新型,相对寿命较长的CI(H2O-) 中间状态.
结论:
- 表面的水电荷转移大大加快了与水的克里吉中间反应.
- 这些发现为大气氧化能力提供了新的见解,
- 突出了水界面动力学在加速水界面反应中的关键作用.
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