相关实验视频

Updated: Jul 16, 2025

Photoelectron Imaging of Anions Illustrated by 310 Nm Detachment of F−

Photoelectron Imaging of Anions Illustrated by 310 Nm Detachment of F⁻

Published on: July 27, 2018

关于BiB的电子结构和自旋轨道合,来自冷冷却BiB-离子的光电子成像

Han-Wen Gao¹, Hyun Wook Choi¹, Jie Hui¹

¹Department of Chemistry, Brown University, Providence, Rhode Island 02912, USA.

The Journal of chemical physics

|September 15, 2023

概括

我们测量了BiB分子的电子亲和力为2.010(1) eV. 低温冷却解决了BiB中复杂的电子状态和自旋轨道合,揭示了其基本状态配置.

科学领域:

物理化学物理化学
原子和分子物理原子和分子物理
量子化学是一个量子化学.

背景情况:

了解像BiB这样的二原子分子的电子结构和化学键,对于预测它们的反应性和特性至关重要.
在BiB中存在开放外配置和强大的自旋轨道合,使其电子状态的分析变得复杂.
之前的研究可能受到光谱分辨率的限制,阻碍了对BiB电子景观的完整描述.

研究的目的:

为了研究BiB分子的电子结构和化学键.
为了确定BiB的电子亲和力,并描述其基本和兴奋的电子状态.
阐明旋转轨道合在BiB电子转换中的作用.

主要方法:

低温冷却BiB-离子的高分辨率光电子成像.
使用冷制冷来消除振动热带并解决复杂的脱离过渡.
分析光电子成像中的角分布信息,用于光谱分配.

主要成果:

测定BiB的电子亲和力为2.010(1) eV.
确定了BiB-的基本状态为2Π(3/2) (σ2π3),BiB的基本状态为3Σ-(0+) (σ2π2).
观察到BiB的八个低位自旋轨道激发状态,包括由于电子从σ和π轨道脱离而导致的禁止过渡.

结论:

低温冷却对于获得尺寸精选集群的高分辨率光电子光谱至关重要,使得详细的电子结构研究成为可能.
该研究提供了关于BiB分子中低电子状态和自旋轨道合效应的全面信息.
这些发现增强了我们对重二原子分子中的化学键和电子性质的理解.

更多相关视频

Novel Techniques for Observing Structural Dynamics of Photoresponsive Liquid Crystals

Novel Techniques for Observing Structural Dynamics of Photoresponsive Liquid Crystals

Published on: May 29, 2018

Experimental Methods for Spin- and Angle-Resolved Photoemission Spectroscopy Combined with Polarization-Variable Laser

Experimental Methods for Spin- and Angle-Resolved Photoemission Spectroscopy Combined with Polarization-Variable Laser

Published on: June 28, 2018

相关概念视频

π Electron Effects on Chemical Shift: Overview

π Electron Effects on Chemical Shift: Overview

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,...

Spin–Spin Coupling: Three-Bond Coupling (Vicinal Coupling)

Spin–Spin Coupling: Three-Bond Coupling (Vicinal Coupling)

Vicinal or three-bond coupling is commonly observed between protons attached to adjacent carbons. Here, nuclear spin information is primarily transferred via electron spin interactions between adjacent C‑H bond orbitals. This generally favors the antiparallel arrangement of spins, so 3J values are usually positive.
The extent of coupling depends on the C‑C bond length, the two H‑C‑C angles, any electron-withdrawing substituents, and the dihedral angle between the...

Spin–Spin Coupling Constant: Overview

Spin–Spin Coupling Constant: Overview

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...

NMR Spectroscopy: Spin–Spin Coupling

NMR Spectroscopy: Spin–Spin Coupling

The spin state of an NMR-active nucleus can have a slight effect on its immediate electronic environment. This effect propagates through the intervening bonds and affects the electronic environments of NMR-active nuclei up to three bonds away; occasionally, even farther. This phenomenon is called spin–spin coupling or J-coupling. Coupling interactions are mutual and result in small changes in the absorption frequencies of both nuclei involved. While nuclei of the same element are involved...

π Electron Effects on Chemical Shift: Aromatic and Antiaromatic Compounds

π Electron Effects on Chemical Shift: Aromatic and Antiaromatic Compounds

In aromatic compounds, such as benzene, the circulation of (4n + 2) π-electrons sets up a diamagnetic or diatropic ring current around the perimeter of the molecule. This current induces a magnetic field that opposes the external field inside the ring and reinforces it on the outside. The protons in benzene are deshielded and exhibit high chemical shifts in the range 6.5–8.5 ppm. The shielding effect at the center of the ring is evident in complex aromatic molecules, such as...

Spin–Spin Coupling: One-Bond Coupling

Spin–Spin Coupling: One-Bond Coupling

Coupling interactions are strongest between NMR-active nuclei bonded to each other, where spin information can be transmitted directly through the pair of bonding electrons. While nuclei polarize their electrons to the opposite spins, the bonding electron pair has opposite spins. Configurations with antiparallel nuclear spins are expected to be lower in energy. When coupling makes antiparallel states more favorable, J is considered to have a positive value. The one-bond coupling constant, 1J,...