Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Concept Videos

Spin–Spin Coupling Constant: Overview01:08

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 have a...
Spin–Spin Coupling: One-Bond Coupling01:17

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,...
NMR Spectroscopy: Spin–Spin Coupling01:08

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 in...
Spin–Spin Coupling: Two-Bond Coupling (Geminal Coupling)01:20

Spin–Spin Coupling: Two-Bond Coupling (Geminal Coupling)

Two NMR-active nuclei bonded to a central atom can be involved in geminal or two-bond coupling. Geminal coupling is commonly seen between diastereotopic protons in chiral molecules and unsymmetrical alkenes, among others.
The central atom need not be NMR-active because its electrons are affected by the electron polarization of the spin-active atoms. However, spin information is transmitted less effectively than in one-bond coupling, and 2J values are usually weaker than 1J values. The energy of...
Spin–Spin Coupling: Three-Bond Coupling (Vicinal Coupling)01:22

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 involved orbitals. The...
Sequence Networks of Rotating Machines01:24

Sequence Networks of Rotating Machines

A Y-connected synchronous generator, grounded through a neutral impedance, is designed to produce balanced internal phase voltages with only positive-sequence components. The generator's sequence networks include a source voltage that is exclusively in the positive-sequence network. The sequence components of line-to-ground voltages at the generator terminals illustrate this configuration.
Zero-sequence current induces a voltage drop across the generator's neutral impedance and other...

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

Ultra-Wideline 2D Correlations Among Low-γ Species in Solid-State NMR via the Progressive Saturation of a Common Proton Reservoir.

Chemistry (Weinheim an der Bergstrasse, Germany)·2026
Same author

On the effects of hyperpolarized water-based dissolution on the solute and solvent <sup>1</sup>H NMR spectra of small molecules.

Physical chemistry chemical physics : PCCP·2026
Same author

14.1 T Liquid-State <sup>19</sup>F Overhauser Dynamic Nuclear Polarization in an Analytical Organic Setting.

Journal of the American Chemical Society·2026
Same author

Assessing the treatment of pancreatic ductal adenocarcinoma by deuterium metabolic imaging: a preclinical study.

Magma (New York, N.Y.)·2026
Same author

Enhanced Sensitivity and Resolution in Biomolecular CEST NMR Experiments Using the Extended Hadamard Encoding Scheme.

Analytical chemistry·2025
Same author

Steady-state free precession NMR in solids undergoing magic angle spinning.

The Journal of chemical physics·2025

Related Experiment Video

Updated: May 22, 2026

Measurement of Microtubule Dynamics by Spinning Disk Microscopy in Monopolar Mitotic Spindles
08:31

Measurement of Microtubule Dynamics by Spinning Disk Microscopy in Monopolar Mitotic Spindles

Published on: November 15, 2019

Controlling spin-spin network dynamics by repeated projective measurements.

Christian O Bretschneider1, Gonzalo A Alvarez, Gershon Kurizki

  • 1Department of Chemical Physics, Weizmann Institute of Science, Rehovot, 76100, Israel.

Physical Review Letters
|May 1, 2012
PubMed
Summary
This summary is machine-generated.

Repeatedly projecting quantum states, inspired by the quantum Zeno effect, enhances spin network manipulations. This robust method suppresses unwanted coherences, simplifying complex spin system control and enabling precise coupling constant determination in nuclear magnetic resonance.

More Related Videos

Real-Time Proxy-Control of Re-Parameterized Peripheral Signals using a Close-Loop Interface
11:54

Real-Time Proxy-Control of Re-Parameterized Peripheral Signals using a Close-Loop Interface

Published on: May 8, 2021

Measuring the Spin-Lattice Relaxation Magnetic Field Dependence of Hyperpolarized [1-13C]pyruvate
11:57

Measuring the Spin-Lattice Relaxation Magnetic Field Dependence of Hyperpolarized [1-13C]pyruvate

Published on: September 13, 2019

Related Experiment Videos

Last Updated: May 22, 2026

Measurement of Microtubule Dynamics by Spinning Disk Microscopy in Monopolar Mitotic Spindles
08:31

Measurement of Microtubule Dynamics by Spinning Disk Microscopy in Monopolar Mitotic Spindles

Published on: November 15, 2019

Real-Time Proxy-Control of Re-Parameterized Peripheral Signals using a Close-Loop Interface
11:54

Real-Time Proxy-Control of Re-Parameterized Peripheral Signals using a Close-Loop Interface

Published on: May 8, 2021

Measuring the Spin-Lattice Relaxation Magnetic Field Dependence of Hyperpolarized [1-13C]pyruvate
11:57

Measuring the Spin-Lattice Relaxation Magnetic Field Dependence of Hyperpolarized [1-13C]pyruvate

Published on: September 13, 2019

Area of Science:

  • Quantum physics
  • Nuclear Magnetic Resonance (NMR) spectroscopy
  • Quantum information science

Background:

  • Quantum systems, such as coupled spins, are susceptible to environmental noise and decoherence.
  • Precisely controlling the evolution of complex spin networks is challenging, often requiring intricate pulse sequences.
  • The quantum Zeno effect, where frequent measurements inhibit system evolution, offers a potential avenue for control.

Purpose of the Study:

  • To demonstrate a robust method for controlling coupled-spin network evolution using repeated state projections.
  • To leverage the quantum Zeno effect to suppress unwanted coherences and guide quantum state evolution.
  • To apply this method for accurate determination of coupling constants in complex spin systems.

Main Methods:

  • Utilizing repeated projections of evolving quantum states onto diagonal density-matrix states (populations).
  • Exploiting the quantum Zeno effect to eliminate unwanted quantum correlations (coherences).
  • Implementing the technique in liquid-state nuclear magnetic resonance experiments.

Main Results:

  • Achieved highly effective coupled-spin network manipulations through population projections.
  • Demonstrated a relaxation-like behavior in polarization transfers within N-spin networks.
  • Successfully determined coupling constants for complex spin-coupling topologies.

Conclusions:

  • Repeated population projections offer a robust and effective alternative to complex pulse trains for controlling quantum dynamics.
  • The quantum Zeno effect can be harnessed to simplify the control of quantum information processing and metrology.
  • This approach provides a powerful tool for characterizing complex spin interactions in systems like liquid-state NMR.