尺寸分辨率水的八秒光谱
Xiaochun Gong1,2, Saijoscha Heck1, Denis Jelovina1
1Laboratorium für Physikalische Chemie, ETH Zürich, Zürich, Switzerland.
Nature
|July 12, 2022
概括
研究水中的电子动力学至关重要. 新的阿托秒光谱揭示了受水大小影响的电子孔移位如何影响光离子化时间延迟.
科学领域:
- 物理化学
- 一秒钟的科学
- 分子光谱学
背景情况:
- 水中的电子动力学对许多过程至关重要.
- 实时研究这些动态存在重大挑战.
- 在分子层面了解电子的行为是关键.
研究的目的:
- 为了研究水中的电子动态.
- 了解分子添加对光离子化时间延迟的影响.
- 建立一个分子层面的电子孔移位的理解.
主要方法:
- 开发和应用分秒尺寸分辨率的集群光谱.
- 在不同大小的水中测量光离子化时间延迟.
- 分析集群大小,电子孔延伸和时间延迟之间的关系.
主要成果:
- 光离子化时间延迟随着大小增加到四到五个分子.
- 在较大的水群中, 延迟显示最小的变化.
- 测量的延迟与电子孔的空间延伸相关,它随着越来越多的混乱而局部化.
结论:
- 光离子延迟对电子孔移位很敏感.
- 电子结构与秒速光电化动力学之间存在直接联系.
- 提供了关于电子孔移位及其在水中的动态的新见解.
相关概念视频
Atomic Absorption Spectroscopy: Atomization Methods
650
Atomic Absorption Spectroscopy (AAS) atomizes samples through flame atomization or electrothermal atomization. Flame atomization typically involves a nebulizer and spray chamber assembly to combine the sample with a fuel–oxidant mixture, creating a fine aerosol mist that enters a burner. Typically, the fuel and oxidant are combined in an approximately stoichiometric ratio. However, for atoms that are easily oxidized, a fuel-rich mixture may be more advantageous. Only about 5% of the...
650
Atomic Fluorescence Spectroscopy
492
Atomic fluorescence spectroscopy (AFS) is an analytical technique that involves the electronic transitions of atoms in a flame, furnace, or plasma being excited by electromagnetic (EM) radiation. When these atoms absorb energy, they become excited and subsequently release energy as they return to their original state. This emitted light, or "fluorescence," is observed at a right angle to the incident beam. Both absorption and emission processes transpire at distinct wavelengths, which...
492
Atomic Spectroscopy: Absorption, Emission, and Fluorescence
1.3K
Atomic spectroscopy is a vital tool in elemental analysis, both qualitatively and quantitatively. It can be broadly divided into optical spectroscopy, mass spectroscopy, and X-ray spectroscopy methods. The optical spectroscopic methods are atomic absorption spectroscopy (AAS), atomic emission spectroscopy (AES), and atomic fluorescence spectroscopy (AFS). The first step in all three methods is atomization, where the solid, liquid, or solution-phase samples are converted into gas-phase atoms and...
1.3K
UV–Vis Spectroscopy: Molecular Electronic Transitions
1.7K
In Ultraviolet–Visible (UV–Vis) spectroscopy, the absorption of electromagnetic radiation is used to probe the electronic structure of molecules. This technique provides insights into molecular electronic transitions, particularly the movement of electrons between different molecular orbitals. Radiation is absorbed if the energy of the electromagnetic radiation passing through the molecule is precisely equal to the energy difference between the excited and ground states. During this...
1.7K
IR Spectroscopy: Hooke's Law Approximation of Molecular Vibration
1.6K
A covalently bonded heteronuclear diatomic molecule can be modeled as two vibrating masses connected by a spring. The vibrational frequency of the bond can be expressed using an equation derived from Hooke's law, which describes how the force applied to stretch or compress a spring is proportional to the displacement of the spring. In this case, the atoms behave like masses, and the bond acts like a spring.
According to Hooke's law, the vibrational frequency is directly proportional to...
According to Hooke's law, the vibrational frequency is directly proportional to...
1.6K
Atomic Absorption Spectroscopy: Overview
2.4K
Atomic absorption spectroscopy (AAS) is a technique used to analyze elements by measuring electromagnetic radiation (EMR) absorbed by atoms, which causes them to transition to a higher-energy orbit. The most crucial step in AAS is atomization, where the analyte is converted into gas-phase atoms, typically through a flame or furnace. Some of these atoms become thermally excited in the flame, while most remain in the ground state.
When irradiated by EMR of a particular wavelength, these...
When irradiated by EMR of a particular wavelength, these...
2.4K


