通过质谱测量捕获反应性单联的中间体
Qiuling Zheng1, Yong Liu2, Qinghao Chen2
1Center for Intelligent Chemical Instrumentation, Department of Chemistry and Biochemistry, Edison Biotechnology Institute, Ohio University , Athens, Ohio 45701, United States.
Journal of the American Chemical Society
|October 27, 2015
概括
研究人员使用脱电喷射电离质谱法 (DESI-MS) 检测出一种反应性中介物,Pd(0) L. 这一突破可以实时监测涉及和联体的催化反应.
科学领域:
- 有机金属化学
- 催化剂
- 分析化学
背景情况:
- 中介物在交叉合反应中至关重要,但通常寿命短且难以检测.
- 布赫瓦尔德预催化剂在C-N合反应中被广泛使用,但其活性物种仍然难以捉摸.
- 了解催化机制需要直接观察反应性中间体.
研究的目的:
- 检测和描述难以捉摸的单联中介物 (Pd)
- 在实时监测催化反应路径.
- 研究氧化添加和C-N合的后续步骤.
主要方法:
- 使用基的布克瓦尔德预催化剂的激活.
- 实时反应监测采用吸附电喷射电离质谱法 (DESI-MS).
- 在现场分析中间体和反应产物.
主要成果:
- 首次成功检测出与单素结合的反应性中介物Pd0L.
- 通过DESI-MS可以直接观察从前催化剂激活中产生的Pd(0) L的形成.
- 随后的步骤,包括用烯化物和C-N合的氧化添加,也进行了探测.
结论:
- 直接检测Pd(0) L为催化机制提供了关键的洞察力.
- DESI-MS是催化系统中反应性中间体实时监测的强大工具.
- 这项工作促进了对催化交叉合反应的理解和优化.
相关概念视频
Mass Spectrometry: Alkyne Fragmentation
2.3K
The fragmentation of alkynes preferentially occurs at the carbon–carbon bond between the α and β carbon of the alkyne bond to generate a 3-propynyl cation (or propargyl cation). In terminal alkynes, there is the only type of fragmentation that yields the 3-propynyl cation. The unsubstituted 3-propynyl cation exhibits a peak at a mass-to-charge ratio of 39. In internal alkynes, the 3-propynyl cation is substituted. For example, 2-pentyne fragments into methyl-substituted 3-propynyl cation,...
2.3K
Inductively Coupled Plasma–Mass Spectrometry (ICP–MS): Overview
2.7K
In inductively coupled plasma–mass spectrometry (ICP–MS), an inductively coupled plasma (ICP) torch is used as an atomizer and ionizer. Solid samples are dissolved and volatilized before being introduced into the high-temperature argon plasma, while solution samples are nebulized and passed through the high-temperature argon plasma. Plasma dissociates the analytes and ionizes their component atoms to form a mixture of positive ions and molecular species. The positive ions are then...
2.7K
Gas Chromatography: Types of Detectors-II
1.4K
In gas chromatography, different detectors are employed to meet specific analytical needs. These detectors are often categorized based on their detection mechanisms and the types of compounds they are best suited to analyze. Thermal Conductivity Detectors (TCD), Flame Ionization Detectors (FID), and Electron Capture Detectors (ECD) represent common categories, each with unique operating principles and applications. However, beyond these, several other detectors are designed for more specialized...
1.4K
![Mizoroki-Heck Cross-coupling Reactions Catalyzed by Dichloro{bis[1,1',1''-phosphinetriyltripiperidine]}palladium Under Mild Reaction Conditions](/_next/image?url=https%3A%2F%2Fcloudfront.jove.com%2FCDNSource%2Fteasers%2F51444.jpg&w=3840&q=50)

