Related Experiment Video

Updated: Nov 5, 2025

Silicon Nanowires and Optical Stimulation for Investigations of Intra- and Intercellular Electrical Coupling
08:58

Silicon Nanowires and Optical Stimulation for Investigations of Intra- and Intercellular Electrical Coupling

Published on: January 28, 2021

4.7K

Preferential coupling of diamond NV centres in step-index fibres

Shuo Li, Dongbi Bai, Marco Capelli

    Optics Express
    |May 14, 2021
    PubMed

    More Related Videos

    Fabrication of 1-D Photonic Crystal Cavity on a Nanofiber Using Femtosecond Laser-induced Ablation13:02

    Fabrication of 1-D Photonic Crystal Cavity on a Nanofiber Using Femtosecond Laser-induced Ablation

    Published on: February 25, 2017

    9.9K
    Writing Bragg Gratings in Multicore Fibers08:48

    Writing Bragg Gratings in Multicore Fibers

    Published on: April 20, 2016

    8.3K

    Related Concept Videos

    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...
    1.3K
    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...
    1.2K
    ¹H NMR: Long-Range Coupling01:27

    ¹H NMR: Long-Range Coupling

    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...
    2.2K
    ¹H NMR: Interpreting Distorted and Overlapping Signals01:02

    ¹H NMR: Interpreting Distorted and Overlapping Signals

    Spin systems where the difference in chemical shifts of the coupled nuclei is greater than ten times J are called first-order spin systems. These nuclei are weakly coupled, and their chemical shifts and coupling constant can generally be estimated from the well-separated signals in the spectrum.
    As Δν decreases and the signals move closer, the doublets appear increasingly distorted. The intensities of the inner lines increase at the cost of those of the outer lines as the signals are...
    1.2K
    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...
    2.5K
    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,...
    1.2K