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

¹H NMR of Conformationally Flexible Molecules: Temporal Resolution00:52

¹H NMR of Conformationally Flexible Molecules: Temporal Resolution

At room temperature, the chair conformer of cyclohexane undergoes rapid ring flipping between two equivalent chair conformers at a rate of approximately 105 times per second. These two chair conformers are in equilibrium. The rapid ring flipping results in the interconversion of the axial proton to an equatorial proton and an equatorial to the axial proton. Such interconversions are too rapid and cannot be detected on the NMR timescale. Hence, the NMR spectrometer cannot distinguish between the...
¹H NMR of Labile Protons: Temporal Resolution01:10

¹H NMR of Labile Protons: Temporal Resolution

Protons bonded to heteroatoms such as nitrogen and oxygen exhibit a range of chemical shift values. This is due to the varying degree of hydrogen bonding between the proton and the heteroatom in other molecules. The extent of hydrogen bonding affects the electron density around the proton, thereby giving different chemical shift values for the protons in the proton NMR spectrum.
The –OH proton in alcohols typically appears in the range of δ 2 to 5 ppm but can vary depending on the specific...
Double Resonance Techniques: Overview01:12

Double Resonance Techniques: Overview

Double resonance techniques in Nuclear Magnetic Resonance (NMR) spectroscopy involve the simultaneous application of two different frequencies or radiofrequency pulses to manipulate and observe two distinct nuclear spins. One important application of double resonance is spin decoupling, which selectively suppresses coupling with one type of nucleus while observing the NMR signal from another nucleus, simplifying the spectrum and enhancing resolution.
Spin decoupling is usually achieved by...
NMR Spectrometers: Radiofrequency Pulses and Pulse Sequences01:17

NMR Spectrometers: Radiofrequency Pulses and Pulse Sequences

A pulse is a short burst of radio waves distributed over a range of frequencies that simultaneously excites all the nuclei in the sample. Upon passing a radio frequency pulse along the x-axis, the nuclei absorb energy corresponding to their Larmor frequencies and achieve resonance. This shifts the net magnetization vector from the z-axis toward the transverse plane. This angle of rotation of the magnetization vector, or the flip angle, is proportional to the duration and intensity of the pulse.
Two-Dimensional (2D) NMR: Overview01:12

Two-Dimensional (2D) NMR: Overview

The 1D NMR spectrum of large and complex molecules like natural products has complicated splitting patterns and overlapping signals, which can be easily interpreted using 2-dimensional (2D) NMR. Unlike 1D NMR, 2D NMR has two frequency axes that provide the coupling information between the nucleus A and nucleus B in a molecule. The process from which 2D spectra are obtained has four steps.
The first step is the preparation period, during which nucleus A is excited with a radiofrequency pulse.
2D NMR: Overview of Heteronuclear Correlation Techniques01:18

2D NMR: Overview of Heteronuclear Correlation Techniques

Heteronuclear correlation spectroscopy is an analytical technique that investigates the coupling between different types of nuclei, often a proton and an X-nucleus, such as carbon-13 or nitrogen-15. This method is commonly used in nuclear magnetic resonance (NMR) spectroscopy to gain insights into complex chemical compounds' structural and compositional aspects. A typical heteronuclear correlation spectrum displays X-nucleus chemical shifts on one axis and a proton spectrum on the other axis.

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

Femtosecond modulation of electron correlations in a Luttinger liquid.

Science advances·2026
Same author

Author Correction: High-order harmonic generation in an organic molecular crystal.

Nature communications·2026
Same author

Fragmentation dynamics of CS2 dications and trications following S 2p ionization.

The Journal of chemical physics·2026
Same author

Lock-in amplitude-phase correlations for enhanced imaging and segmentation in stimulated Raman scattering microscopy.

Optics express·2025
Same author

High-order harmonic generation in an organic molecular crystal.

Nature communications·2025
Same author

Entanglement in photoionisation reveals the effect of ionic coupling in attosecond time delays.

Nature communications·2025
Same journal

Erratum for the Research Article "Detecting supramolecular organic nanoparticles during heat wave".

Science (New York, N.Y.)·2026
Same journal

Local signals, systemic decline.

Science (New York, N.Y.)·2026
Same journal

The mechanics of liver regeneration.

Science (New York, N.Y.)·2026
Same journal

Computing in a memory with physics.

Science (New York, N.Y.)·2026
Same journal

Retraction.

Science (New York, N.Y.)·2026
Same journal

Making time.

Science (New York, N.Y.)·2026
查看所有相关文章

相关实验视频

Updated: Jun 28, 2026

Measurement of Ultrafast Vibrational Coherences in Polyatomic Radical Cations with Strong-Field Adiabatic Ionization
08:22

Measurement of Ultrafast Vibrational Coherences in Polyatomic Radical Cations with Strong-Field Adiabatic Ionization

Published on: August 6, 2018

在N2O4中使用高波生成探测的时间解析动态.

Wen Li1, Xibin Zhou, Robynne Lock

  • 1JILA and Department of Physics, University of Colorado and National Institute of Standards and Technology, Boulder, CO 80309-0440, USA. wli@jila.colorado.edu

Science (New York, N.Y.)
|November 1, 2008
PubMed
概括
此摘要是机器生成的。

高波生成揭示了分子中的合电子和核动力学. 在二四氧化物中的振动会引起电子状态交换,导致不同的光发射模式.

更多相关视频

Direct Imaging of Laser-driven Ultrafast Molecular Rotation
10:52

Direct Imaging of Laser-driven Ultrafast Molecular Rotation

Published on: February 4, 2017

All-electronic Nanosecond-resolved Scanning Tunneling Microscopy: Facilitating the Investigation of Single Dopant Charge Dynamics
11:33

All-electronic Nanosecond-resolved Scanning Tunneling Microscopy: Facilitating the Investigation of Single Dopant Charge Dynamics

Published on: January 19, 2018

相关实验视频

Last Updated: Jun 28, 2026

Measurement of Ultrafast Vibrational Coherences in Polyatomic Radical Cations with Strong-Field Adiabatic Ionization
08:22

Measurement of Ultrafast Vibrational Coherences in Polyatomic Radical Cations with Strong-Field Adiabatic Ionization

Published on: August 6, 2018

Direct Imaging of Laser-driven Ultrafast Molecular Rotation
10:52

Direct Imaging of Laser-driven Ultrafast Molecular Rotation

Published on: February 4, 2017

All-electronic Nanosecond-resolved Scanning Tunneling Microscopy: Facilitating the Investigation of Single Dopant Charge Dynamics
11:33

All-electronic Nanosecond-resolved Scanning Tunneling Microscopy: Facilitating the Investigation of Single Dopant Charge Dynamics

Published on: January 19, 2018

科学领域:

  • 物理化学 物理化学
  • 量子动力学 量子动力学是什么?
  • 分子光谱学 分子光谱学

背景情况:

  • 高波生成 (HHG) 探测原子和小分子中的超快电子动态.
  • 在复杂的多原子分子中理解HHG需要考虑合的电子和核运动.
  • 之前的研究集中在更简单的系统上,使多原子分子动力学在强烈的场域下得到了较少的探索.

研究的目的:

  • 通过使用高波生成,研究多原子分子中的联电子和核动力学.
  • 阐明分子振动在调节电子回碰撞动态和HHG光谱中的作用.
  • 探索多个分子轨道在强场电离和多原子分子的HHG中的参与.

主要方法:

  • 在二氧化四氧化物 (N2O4) 分子中引起大振幅振动的激发.
  • 高波生成测量以探测电子回碰撞动态.
  • 理论计算以解释观察到的光谱调制和电子状态群体.

主要成果:

  • 证明HHG可以揭示多原子分子中的合电子和核动力学.
  • 观察到N2O4中的振动状态切换机制:道电离在外部转折点进入基离子状态,并在内部转折点进入第一个兴奋状态.
  • 识别出主要在外转点发射的高气爆发,归因于从激发的离子状态中抑制的发射.

结论:

  • 高波生成是研究多原子分子中超快联电子和核动力学的强大工具.
  • 分子振动显著影响电子回碰撞路径和高温气体排放特征.
  • 强场电离和HHG在结构动态分子中涉及多个分子轨道的参与.