在大气水溶液中的4-chlorobiphenyl与酸的光化学反应
Yue Yang1,2,3, Yadong Hu1,2,3, Wenli Liu1,2,3
1School of Resource and Environmental Engineering, Hefei University of Technology Hefei 230009 P.R. China czzhu@hfut.edu.cn wangmingjin@vip.163.com +86 551 62901649 +86 551 62901523.
这项研究研究了4-chlorobiphenyl (4-PCB) 和酸 (HONO) 之间的大气水相反应. 研究人员确定了反应动力学,并确定了这种环境相关的光化学过程中产生的关键产品.
科学领域:
- 环境化学
- 大气化学
- 摄影化学
背景情况:
- 4-双 (4-PCB) 是大气中存在的一种持久性有机污染物.
- 酸 (HONO) 是大气中的关键氧化剂,有助于污染物降解.
- 了解4-PCB在水相中的光化学反应对于评估其环境命运至关重要.
研究的目的:
- 在大气水系统中研究4-PCB与HONO的光化学反应机制.
- 确定反应动力学,并确定中间产品和最终产品.
- 阐明这些产品的形成途径.
主要方法:
- 使用355nm激光闪光光溶解与365nm紫外线稳定状态辐射.
- 分析了初始4-PCB度,pH和HONO度对转化率的影响.
- 关键反应步骤的量化第二阶段反应速率常数.
主要成果:
- 基 (HO ̇) 对4-PCB的攻击形成了一个速度常数为 (9.0 ± 1) × 109 L mol-1 s-1 的4-PCB-OH附加物.
- 4-PCB-OH添加物与HONO和O2的反应速度分别为 (5.3 ± 0.1) × 106 L mol-1 s-1 和 (4.9 ± 0.2) × 106 L mol-1 s-1.
- 已识别的最终产品包括4-基,4-基-4-,4-基-4-基和4-基-2-基.
结论:
- 4-PCB与HONO的光化学反应通过HO ̇基攻击进行,形成进一步降解的附加物.
- 离子对4-PCB转化的影响最小,而pH和反应物度是重要的因素.
- 这项研究提供了对4-PCB大气降解途径和转化产品的见解.
更多相关视频
07:30A Direct, Regioselective and Atom-Economical Synthesis of 3-Aroyl-N-hydroxy-5-nitroindoles by Cycloaddition of 4-Nitronitrosobenzene with Alkynones
Published on: January 21, 2020
07:06Continuous Flow Chemistry: Reaction of Diphenyldiazomethane with p-Nitrobenzoic Acid
Published on: November 15, 2017
相关概念视频
Electrophilic Aromatic Substitution: Nitration of Benzene
Hydrolysis of Chlorobenzene to Phenol: Dow Process
Electrophilic Aromatic Substitution: Chlorination and Bromination of Benzene
Reactions at the Benzylic Position: Halogenation
Nucleophilic Aromatic Substitution: Elimination–Addition
Rate-Determining Steps
In a multistep reaction mechanism, one of the elementary steps progresses significantly slower than the others. This slowest step is called the rate-limiting step (or rate-determining step). A reaction cannot proceed faster than its slowest step, and hence, the rate-determining step limits the overall reaction rate.
The concept of rate-determining step can be understood from the analogy of a 4-lane freeway with a short-stretch of traffic-bottleneck caused due to...
![[DPEPhosbcpCu]PF6: A General and Broadly Applicable Copper-Based Photoredox Catalyst](/_next/image?url=https%3A%2F%2Fcloudfront.jove.com%2FCDNSource%2Fteasers%2F59739.jpg&w=3840&q=50)