气相形的高波生成光谱学
Chiara Morassut1,2, Arun Ravindran3, Alessandra Ciavardini3
1Laboratoire de Chimie Théorique, Sorbonne Université, CNRS, Paris F-75005, France.
The journal of physical chemistry. A
|March 12, 2024
概括
形分子中的高波生成 (HHG) 揭示了超出预测的切断界限的波. 电子束状态和多个分子轨道有助于这种复杂的强场动态.
科学领域:
- 量子光学是一种量子光学.
- 分子物理学 分子物理学
- 强电场物理学 强电场物理学
背景情况:
- 高生成 (HHG) 是强场物理学中的一个关键过程,从原子或分子中产生高能光子,与强烈的激光场相互作用.
- 标准三步模型 (3SM) 经常预测HHG光谱的切线,但实验观测经常超出这个极限.
- 了解底层电子动态对于解释和控制高气频谱至关重要.
研究的目的:
- 实验测量和理论模拟随机对齐的形 (CHBr3) 分子的高子生成 (HHG) 光谱.
- 为了研究电子束状态和多个分子轨道对超出预测的切断范围的HHG光谱的贡献.
- 为了阐明复杂的电子动态,负责形中观察到的波生成.
主要方法:
- 在各种激光脉冲强度下对形分子进行HHG光谱的实验测量.
- 使用实时依赖时间的配置相互作用与单次激发 (RT-TDCI-SE) 的理论模拟.
- 将HHG信号分解为单个分子轨道的贡献,以分析电子动态.
主要成果:
- 实验观察到的HHG光谱远远超出了3SM预测的切断线,来自最高占用分子轨道 (HOMO) 的电离.
- 理论模拟证实,电子边界状态对HHG信号有很大的贡献.
- 分析显示,超出预期切线 (约20-30 eV) 的波源于较低的分子轨道,特别是HOMO-6和HOMO-9的贡献,表明复杂的多轨道动态.
- 考虑了形离子对更高波 (H29-H45) 的潜在贡献,但并没有最终排除.
结论:
- 形体的HHG光谱是由复杂的多轨道强场动态形成的,超出了简单模型的预测范围.
- 电子束状态在产生高能波中起着至关重要的作用,特别是超出HOMO电离切线的高能波.
- 需要进一步的研究,以充分确定形离子在产生观察到的最高能量波的作用.
相关概念视频
Spin–Spin Coupling Constant: Overview
921
In bromoethane, the three methyl protons are coupled to the two methylene protons that are three bonds away. In accordance with the n+1 rule, the signal from the methyl protons is split into three peaks with 1:2:1 relative intensities. The methylene protons appear as a quartet, with the relative intensities of 1:3:3:1.
Qualitatively, any spin plus-half nucleus polarizes the spins of its electrons to the minus-half state. Consequently, the paired electron in the hydrogen–carbon bond must...
Qualitatively, any spin plus-half nucleus polarizes the spins of its electrons to the minus-half state. Consequently, the paired electron in the hydrogen–carbon bond must...
921
Mass Spectrometry: Alkyl Halide Fragmentation
1.1K
Chlorine isotopes exist as 35Cl and 37Cl in a 3:1 ratio, while bromine isotopes exist as 79Br and 81Br in a 1:1 ratio. The mass spectrum of alkyl halides typically produces two distinct molecular ion peaks, the molecular ion peak, [M], and the molecular ion plus two, [M + 2] peak. The relative heights of these two peaks are proportional to the isotopic abundance ratios of the halide. For example, 2‐chloropropane and 1‐bromopropane display two peaks with relative peak heights in a 3:1 and...
1.1K
IR Spectroscopy: Molecular Vibration Overview
2.2K
When Infrared (IR) radiation passes through a covalently bonded molecule, the bonds transition from lower to higher vibrational levels. The fundamental vibrational motions that result in infrared absorption can be classified as stretching or bending vibrations.
Stretching vibrations are vibrational motions that occur along the bond line, changing the bond length or distance between two bonded atoms. They are further distinguished as symmetric or asymmetric. In symmetric stretching, the...
Stretching vibrations are vibrational motions that occur along the bond line, changing the bond length or distance between two bonded atoms. They are further distinguished as symmetric or asymmetric. In symmetric stretching, the...
2.2K
NMR Spectroscopy of Benzene Derivatives
8.2K
Simple unsubstituted benzene has six aromatic protons, all chemically equivalent. Therefore, benzene exhibits only a singlet peak at δ 7.3 ppm in the 1H NMR spectrum. The observed shift is far downfield because the aromatic ring current strongly deshields the protons. Any substitution on the benzene ring makes the aromatic protons nonequivalent, and the protons split each other. The peak is, therefore, no longer a singlet and the splitting pattern and their associated coupling...
8.2K
Emission Spectra
52.6K
When solids, liquids, or condensed gases are heated sufficiently, they radiate some of the excess energy as light. Photons produced in this manner have a range of energies, and thereby produce a continuous spectrum in which an unbroken series of wavelengths is present.
52.6K
IR Spectrum Peak Broadening: Hydrogen Bonding
982
The vibrational frequency of a bond is directly proportional to its bond strength. As a result, stronger bonds vibrate at higher frequencies, while weaker bonds vibrate at lower frequencies. The stretching vibration of the strong O–H bond in alcohols and phenols (very dilute solution or gas phase) appears as a sharp peak at 3600–3650 cm−1.
However, the extent of hydrogen bonding influences the observed stretching frequency and band broadening. Intermolecular or intramolecular...
However, the extent of hydrogen bonding influences the observed stretching frequency and band broadening. Intermolecular or intramolecular...
982


