在不和的Criegee中间体中快速转移1,6H原子
Anne S Hansen1, Yujie Qian1, Christopher A Sojdak1
1Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6323 United States.
通过红外激活的1,6原子转移,二甲氧化物Criegee中间体的新机制迅速形成基 (OH) 基. 这一途径涉及形状变化和道,增强了热带层的OH产量.
科学领域:
- 大气化学
- 化学动力学
- 光谱学
背景情况:
- 在大气氧化过程中,Criegee中间体是关键物种.
- 了解它们的单分子衰变路径对于大气建模至关重要.
- 之前的研究集中在双分子反应上,对复杂的Criegee中间体的单分子衰变知之甚少.
研究的目的:
- 建立一个新型的1,6原子转移机制,用于2-丁醇氧化物Criegee中间体.
- 研究红外激活和形态异构在单分子衰变中的作用.
- 量化从这种途径产生基的速度.
主要方法:
- 合成一种新的前体 (Z/E-1,3-diiodobut-1-ene) 来产生一种联的四碳Criegee中间体.
- 红外 (红外) 作用光谱与紫外线激光诱导的光检测OH基.
- 理论计算包括构造分析,无声频率和统计RRKM理论.
主要成果:
- 在红外激活时,通过基1,6原子转移,对2-丁烯氧化物快速单分子衰变的实验证据.
- 在反应路径中涉及的低位 (tZZ) 调节器和高能 (cZZ) 调节器的识别
- 量子力学道显著提高单分子衰变速率,有效衰变速率为~10^8s^-1在~3000cm^-1.
结论:
- 已经阐明了一种新的,快速的单分子衰变途径,用于2-丁烯氧化物Criegee中间体.
- 这种机制对基的产生有显著的贡献,特别是在非光解条件下.
- 预计这些发现将改善基臭氧化和热层OH基度的大气模型.
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