Jove
Visualize
联系我们
JoVE
x logofacebook logolinkedin logoyoutube logo
关于 JoVE
概览领导团队博客JoVE 帮助中心
作者
出版流程编辑委员会范围与政策同行评审常见问题投稿
图书馆员
用户评价订阅访问资源图书馆顾问委员会常见问题
研究
JoVE JournalMethods CollectionsJoVE Encyclopedia of Experiments存档
教育
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab Manual教师资源中心教师网站
使用条款与条件
隐私政策
政策

相关概念视频

The Pauli Exclusion Principle03:06

The Pauli Exclusion Principle

38.6K
The arrangement of electrons in the orbitals of an atom is called its electron configuration. We describe an electron configuration with a symbol that contains three pieces of information:
38.6K
Molecular Orbital Theory II03:51

Molecular Orbital Theory II

19.3K
Molecular Orbital Energy Diagrams
19.3K
Nuclear Overhauser Enhancement (NOE)01:07

Nuclear Overhauser Enhancement (NOE)

739
Irradiation of a spin-active nucleus causes an increase or decrease in the signal intensity of neighboring nuclei that are not necessarily chemically bonded or involved in J-coupling.  This phenomenon, called the Nuclear Overhauser Enhancement (NOE), results from through-space interactions between the nuclear spins. The NOE effect decreases with increasing internuclear distance and is generally not observed beyond 4 angstroms. In NOE, dipole-dipole interactions between neighboring...
739
Atomic Nuclei: Nuclear Spin State Overview01:03

Atomic Nuclei: Nuclear Spin State Overview

998
NMR-active nuclei have energy levels called 'spin states' that are associated with the orientations of their nuclear magnetic moments. In the absence of a magnetic field, the nuclear magnetic moments are randomly oriented, and the spin states are degenerate. When an external magnetic field is applied, the spin states have only 2 + 1 orientations available to them. A proton with = ½ has two available orientations. Similarly, for a quadrupolar nucleus with a nuclear spin value of...
998
Atomic Nuclei: Nuclear Relaxation Processes01:23

Atomic Nuclei: Nuclear Relaxation Processes

676
In the absence of an external magnetic field, nuclear spin states are degenerate and randomly oriented. When a magnetic field is applied, the spins begin to precess and orient themselves along (lower energy) or against (higher energy) the direction of the field. At equilibrium, a slight excess population of spins exists in the lower energy state. Because the direction of the magnetic field is fixed as the z-axis,  the precessing magnetic moments are randomly oriented around the z-axis.
676
Atomic Nuclei: Nuclear Spin State Population Distribution01:14

Atomic Nuclei: Nuclear Spin State Population Distribution

1.0K
Near absolute zero temperatures, in the presence of a magnetic field, the majority of nuclei prefer the lower energy spin-up state to the higher energy spin-down state. As temperatures increase, the energy from thermal collisions distributes the spins more equally between the two states. The Boltzmann distribution equation gives the ratio of the number of spins predicted in the spin −½ (N−) and spin +½ (N+) states.
1.0K

您也可能阅读

相关文章

通过共同作者、期刊和引用图与本文相关的文章。

排序
Same author

Clusteroluminescent Monosaccharide, Oligosaccharide, and Polysaccharide.

ACS applied materials & interfaces·2026
Same author

Fluorescence mapping of atropisomer populations enabled by through-space conjugation.

Nature communications·2026
Same author

Through-space conjugation-based luminophores: toward redder and more efficient emitters.

Chemical communications (Cambridge, England)·2026
Same author

Through-space interactions of optoelectronic materials.

Chemical Society reviews·2026
Same author

Hydrogen-Bond-Mediated Through-Space Conjugation for the Fabrication of Red-Emissive Solid-State Carbon Dots and Application in LEDs.

Inorganic chemistry·2025
Same author

Manipulation of the through-space interactions in diphenylmethane.

Smart molecules : open access·2025

相关实验视频

Updated: Jul 16, 2025

Excitonic Hamiltonians for Calculating Optical Absorption Spectra and Optoelectronic Properties of Molecular Aggregates and Solids
08:04

Excitonic Hamiltonians for Calculating Optical Absorption Spectra and Optoelectronic Properties of Molecular Aggregates and Solids

Published on: May 27, 2020

8.5K

通过空间相互作用的激发状态奇偶效应

Zuping Xiong1,2,3, Jianyu Zhang4, Jing Zhi Sun1,3

  • 1MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Department of Polymer Science and Engineering, Zhejiang University, Hangzhou 310058, China.

Journal of the American Chemical Society
|September 15, 2023
PubMed
概括

研究人员发现四甲基 (TPA) 具有激发状态奇偶效应. 偶数的TPA表现出强烈的穿越空间相互作用和发光,与奇数的对应物不同,揭示了一个新的光物理现象.

更多相关视频

Experimental Methods for Spin- and Angle-Resolved Photoemission Spectroscopy Combined with Polarization-Variable Laser
09:00

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

Published on: June 28, 2018

10.0K
Spatial Separation of Molecular Conformers and Clusters
10:37

Spatial Separation of Molecular Conformers and Clusters

Published on: January 9, 2014

9.0K

相关实验视频

Last Updated: Jul 16, 2025

Excitonic Hamiltonians for Calculating Optical Absorption Spectra and Optoelectronic Properties of Molecular Aggregates and Solids
08:04

Excitonic Hamiltonians for Calculating Optical Absorption Spectra and Optoelectronic Properties of Molecular Aggregates and Solids

Published on: May 27, 2020

8.5K
Experimental Methods for Spin- and Angle-Resolved Photoemission Spectroscopy Combined with Polarization-Variable Laser
09:00

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

Published on: June 28, 2018

10.0K
Spatial Separation of Molecular Conformers and Clusters
10:37

Spatial Separation of Molecular Conformers and Clusters

Published on: January 9, 2014

9.0K

科学领域:

  • 光物理学
  • 超分子化学
  • 有机化学

背景情况:

  • 奇偶效应是已知的自然现象, 在有机自组合单层和液晶等领域观察到.
  • 现有的奇偶效应与基本状态属性有关,其起源往往不清楚.

研究的目的:

  • 在非结合的四甲基 (TPA) 中发现和描述激发状态奇偶效应.
  • 阐明这种新奇的光物理现象的基本因素.

主要方法:

  • 一系列具有不同链长度的四甲基 (TPA) 的合成.
  • 包括光发光谱在内的实验性表征.
  • 理论计算以了解分子相互作用和特性.

主要成果:

  • 具有偶数碳原子 (C2-TPA,C4-TPA,C6-TPA) 的 TPA 具有强烈的穿越空间相互作用 (TSI),长波长辐射和高量子产量 (QY).
  • 具有奇数基碳原子 (C1-TPA,C3-TPA,C5-TPA,C7-TPA) 的 TPA 显示微不足道的 QY 和最小的 TSI.
  • 这种效应归因于基几何学,分子移动性和分子间包装.

结论:

  • 在四甲基的穿越空间相互作用中发现了激发状态奇偶效应.
  • 这种现象将奇偶效应的理解扩展到光物理,证明了它的普遍性.
  • 灵活的发光TPA显示了光信息加密中的应用潜力.