在化酸中通过弗里曼共振对多光子电离的强烈控制
Ignacio M Casasús1, María E Corrales1,2, Marta L Murillo-Sánchez1
1Departamento de Química Física, Facultad de Ciencias Químicas, Universidad Complutense de Madrid, 28040 Madrid, Spain.
The Journal of chemical physics
|August 15, 2023
概括
酸的多光子电离 (MPI) 显示出一个令人惊的共振,独立于分子结构. 这一发现揭示了激光场强度如何影响分子电离路径和弗里曼共振.
科学领域:
- 物理化学 物理化学
- 分子光谱学 分子光谱学
- 非线性光学 非线性光学
背景情况:
- 多光子电离 (MPI) 是一个由高激光强度影响的复杂过程.
- 强磁场中的斯塔克转移效应可以导致弗里曼共振,其中分子状态与激光光子对齐.
- 了解分子结构对MPI的影响对于控制电离化动态至关重要.
研究的目的:
- 调查线性和分支化酸中分子结构对UV-VUV吸收光谱的影响.
- 为了研究多光子电离 (MPI) 过程和酸中弗里曼共振的产生.
- 阐明6p Rydberg状态在观察到的电离路径中的作用.
主要方法:
- 在MPI实验中使用了800和400nm的五秒激光脉冲.
- 用光电子成像检测来分析电离产物.
- 紫外线-紫外线吸收光谱使用SOLEIL同步发射机设施的VUV里埃变换光谱仪进行测量.
主要成果:
- 在800nm的MPI实验中,在整个酸系列中观察到一种主导共振.
- 这种共振表现出恒定的光电子运动能量,不管酸的分子结构如何.
- 离子化路径涉及6p(2E3/2) 赖德伯格状态与不同的振动激发,表明能量补偿效应.
结论:
- 分子结构对化MPI中观察到的主导共振的影响有限.
- 能量补偿效应解释了恒定的光电子动能与日益增加的链复杂性.
- 这些发现突出了分子结构,激光场效应和电离力学之间的复杂相互作用.
相关概念视频
02:38Electrophilic Addition to Alkynes: Halogenation
8.3K
Introduction
Halogenation is another class of electrophilic addition reactions where a halogen molecule gets added across a π bond. In alkynes, the presence of two π bonds allows for the addition of two equivalents of halogens (bromine or chlorine). The addition of the first halogen molecule forms a trans-dihaloalkene as the major product and the cis isomer as the minor product. Subsequent addition of the second equivalent yields the tetrahalide.
Halogenation is another class of electrophilic addition reactions where a halogen molecule gets added across a π bond. In alkynes, the presence of two π bonds allows for the addition of two equivalents of halogens (bromine or chlorine). The addition of the first halogen molecule forms a trans-dihaloalkene as the major product and the cis isomer as the minor product. Subsequent addition of the second equivalent yields the tetrahalide.
8.3K
02:45Alkyl Halides
16.9K
Structural Properties
Alkyl halides are halogen-substituted alkanes wherein one or more hydrogen atoms of an alkane is replaced by a halogen atom such as fluorine, chlorine, bromine, or iodine. The carbon atom in an alkyl halide is bonded to the halogen atom, which is sp3-hybridized and exhibits a tetrahedral shape.
Unlike alkyl halides, compounds in which a halogen atom is bonded to an sp2 -hybridized carbon atom of a carbon-carbon double bond (C=C) are called vinyl halides. Whereas aryl...
Alkyl halides are halogen-substituted alkanes wherein one or more hydrogen atoms of an alkane is replaced by a halogen atom such as fluorine, chlorine, bromine, or iodine. The carbon atom in an alkyl halide is bonded to the halogen atom, which is sp3-hybridized and exhibits a tetrahedral shape.
Unlike alkyl halides, compounds in which a halogen atom is bonded to an sp2 -hybridized carbon atom of a carbon-carbon double bond (C=C) are called vinyl halides. Whereas aryl...
16.9K
01:27π Electron Effects on Chemical Shift: Overview
1.1K
An applied magnetic field causes loosely bound π-electrons in organic molecules to circulate, producing a local or induced diamagnetic field over a large spatial volume. As the molecules tumble in solution, the field generated by π-electrons in spherical substituents results in a zero net field. However, the net field generated by π-electrons in non-spherical substituents is not zero. The effect of this induced field depends on the orientation of the molecule with respect to B0,...
1.1K
01:13Electrophilic Aromatic Substitution: Fluorination and Iodination of Benzene
6.1K
Bromination and chlorination of aromatic rings by electrophilic aromatic substitution reactions are easily achieved, but fluorination and iodination are difficult to achieve. Fluorine is so reactive that its reaction with benzene is difficult to control, resulting in poor yields of monofluoroaromatic products. To address this, Selectfluor reagent is used as a fluorine source in which a fluorine atom is bonded to a positively charged nitrogen.
6.1K
01:10Radical Reactivity: Steric Effects
1.9K
The presence of electron-donating, electron-withdrawing, or conjugating groups adjacent to a radical center, imparts electronic stabilization to the radicals. Examples of such electronically-stabilized radicals are triphenylmethyl, tetramethylpiperidine‐N‐oxide, and 2,2‐diphenyl‐1‐picrylhydrazyl. These radicals are remarkably stable and are known as persistent radicals. Some of the persistent radicals can even be isolated and purified.
Along with electronic...
Along with electronic...
1.9K
02:17Regioselectivity of Electrophilic Additions to Alkenes: Markovnikov's Rule
14.3K
If a set of reactants can yield multiple constitutional isomers, but one of the isomers is obtained as the major product, the reaction is said to be regioselective. In such reactions, bond formation or breaking is favored at one reaction site over others.
The hydrohalogenation of an unsymmetrical alkene can yield two haloalkane products, depending on which vinylic carbon takes up the halogen. However, one product usually predominates, where hydrogen adds to the vinylic carbon bearing the...
The hydrohalogenation of an unsymmetrical alkene can yield two haloalkane products, depending on which vinylic carbon takes up the halogen. However, one product usually predominates, where hydrogen adds to the vinylic carbon bearing the...
14.3K