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: Two-Bond Coupling (Geminal Coupling)01:20

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

1.5K
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...
1.5K
NMR Spectroscopy: Spin–Spin Coupling01:08

NMR Spectroscopy: Spin–Spin Coupling

3.4K
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...
3.4K
¹H NMR: Long-Range Coupling01:27

¹H NMR: Long-Range Coupling

2.4K
The coupling interactions of nuclei across four or more bonds are usually weak, with J values less than 1 Hz. While these are usually not observed in spectra, the presence of multiple bonds along the coupling pathway can result in observable long-range coupling.
In alkenes, spin information is communicated via σ–π overlap, as seen in allylic (four-bond) and homoallylic (five-bond) couplings. These coupling interactions are stronger when the σ bond is parallel to the alkene...
2.4K
Spin–Spin Coupling: Three-Bond Coupling (Vicinal Coupling)01:22

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

1.3K
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...
1.3K
Spin–Spin Coupling: One-Bond Coupling01:17

Spin–Spin Coupling: One-Bond Coupling

1.2K
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,...
1.2K
Spin–Spin Coupling Constant: Overview01:08

Spin–Spin Coupling Constant: Overview

1.2K
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...
1.2K

You might also read

Related Articles

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

Sort by
Same author

Antimicrobial prophylaxis in companion animal surgery: A scoping review for European Network for Optimization of Antimicrobial Therapy (ENOVAT) guidelines.

Veterinary journal (London, England : 1997)·2024
Same author

Dynamics of bla<sub>OXA-23</sub> gene transmission in Acinetobacter spp. from contaminated veterinary environmental surfaces: an emerging One Health threat?

The Journal of hospital infection·2024
Same author

Structural phase purification of bulk HfO<sub>2</sub>:Y through pressure cycling.

Proceedings of the National Academy of Sciences of the United States of America·2024
Same author

Reply to letter by Hadigal et al. regarding the cost-effectiveness of high dose quadrivalent vaccine in three European countries.

Journal of medical economics·2023
Same author

Chyloperitoneum due to gastric carcinoma: a case report.

Oxford medical case reports·2022
Same author

First Report of <i>Fusarium oxysporum</i> f. sp. <i>cubense</i> Tropical Race 4 Causing Fusarium Wilt in Cavendish Bananas in Peru.

Plant disease·2021

Related Experiment Video

Updated: Apr 26, 2026

Methods of Ex Situ and In Situ Investigations of Structural Transformations: The Case of Crystallization of Metallic Glasses
08:55

Methods of Ex Situ and In Situ Investigations of Structural Transformations: The Case of Crystallization of Metallic Glasses

Published on: June 7, 2018

8.2K

Size-dependent vibronic coupling in α-Fe2O3.

K R O'Neal1, J M Patete2, P Chen1

  • 1Department of Chemistry, University of Tennessee, Knoxville, Tennessee 37996, USA.

The Journal of Chemical Physics
|August 3, 2014
PubMed
Summary
This summary is machine-generated.

Finite size and shape effects influence vibronic coupling in nanoscale iron(III) oxide (α-Fe2O3). Changes in phonon frequency with size reveal increasing 3D character, impacting charge-lattice interactions.

More Related Videos

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

6.5K
Visualizing Uniaxial-strain Manipulation of Antiferromagnetic Domains in Fe1+YTe Using a Spin-polarized Scanning Tunneling Microscope
09:06

Visualizing Uniaxial-strain Manipulation of Antiferromagnetic Domains in Fe1+YTe Using a Spin-polarized Scanning Tunneling Microscope

Published on: March 24, 2019

6.6K

Related Experiment Videos

Last Updated: Apr 26, 2026

Methods of Ex Situ and In Situ Investigations of Structural Transformations: The Case of Crystallization of Metallic Glasses
08:55

Methods of Ex Situ and In Situ Investigations of Structural Transformations: The Case of Crystallization of Metallic Glasses

Published on: June 7, 2018

8.2K
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

6.5K
Visualizing Uniaxial-strain Manipulation of Antiferromagnetic Domains in Fe1+YTe Using a Spin-polarized Scanning Tunneling Microscope
09:06

Visualizing Uniaxial-strain Manipulation of Antiferromagnetic Domains in Fe1+YTe Using a Spin-polarized Scanning Tunneling Microscope

Published on: March 24, 2019

6.6K

Area of Science:

  • Materials Science
  • Condensed Matter Physics
  • Nanotechnology

Background:

  • Vibronic coupling is crucial for understanding electronic and optical properties in materials.
  • Nanoscale materials exhibit unique behaviors due to quantum confinement and surface effects.

Purpose of the Study:

  • To investigate the impact of finite length scales on vibronic coupling in nanoscale iron(III) oxide (α-Fe2O3).
  • To analyze how size and shape influence vibronically activated d-d excitations of Fe(3+).

Main Methods:

  • Experimental measurement of vibronically activated d-d on-site excitations of Fe(3+) in α-Fe2O3 nanoparticles.
  • Oscillator strength analysis to determine phonon frequency and displacement patterns.

Main Results:

  • Finite size and shape effects significantly alter vibronic coupling in nanoscale α-Fe2O3.
  • A crossover in coupled phonon frequency with changing nanoparticle size was observed.
  • This crossover correlates with an increasing three-dimensional character in the phonon displacement pattern.

Conclusions:

  • Nanoscale confinement enhances the flexibility of mixing processes in materials.
  • Findings suggest a strategy for tuning charge-lattice interactions in confined systems.
  • This work provides insights into controlling electronic and optical properties of nanomaterials.