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

Interpreting ¹H NMR Signal Splitting: The (n + 1) Rule01:10

Interpreting ¹H NMR Signal Splitting: The (n + 1) Rule

In the AX proton spin system, proton A can sense the two spin states of a coupled proton X, resulting in a doublet NMR signal with two peaks of equal (1:1) intensity. When proton A is coupled to two equivalent protons (AX2 spin system), the spin states of each X can be aligned with or against the external field, creating three possible scenarios. This results in a 1:2:1  triplet signal, where the central peak corresponds to the chemical shift of A and is twice as large or intense as the others.
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.
¹H NMR: Complex Splitting01:13

¹H NMR: Complex Splitting

A proton M that is coupled to a proton X results in doublet signals for M. However, NMR-active nuclei can be simultaneously coupled to more than one nonequivalent nucleus. When M is coupled to a second proton A, such as in styrene oxide, each peak in the doublet is split into another doublet.
Splitting diagrams or splitting tree diagrams are routinely used to depict such complex couplings. While drawing splitting diagrams, the splitting with the larger coupling constant is usually applied first.
¹H NMR Signal Multiplicity: Splitting Patterns01:13

¹H NMR Signal Multiplicity: Splitting Patterns

When protons A and X are coupled, their nuclear spin energy levels are slightly modified. This is because the energy required to excite proton A to a spin state parallel to proton X is slightly different from the energy required for it to become anti-parallel to spin X. Consequently, there are two possible excitation frequencies for A (A1 and A2), depending on the spin state of X, and vice versa. The mutual nature of coupling implies that the difference between frequencies A1 and A2, indicated...
2D NMR: Heteronuclear Single-Quantum Correlation Spectroscopy (HSQC)01:19

2D NMR: Heteronuclear Single-Quantum Correlation Spectroscopy (HSQC)

Heteronuclear single-quantum correlation spectroscopy (HSQC) is a 2D NMR technique that reveals one-bond correlations between hydrogen and a heteronucleus. The HSQC experiment is similar to the heteronuclear correlation experiment (HETCOR) but is more sensitive. In the HSQC spectrum, the proton chemical shift is plotted on the horizontal F2 axis, while the 13C chemical shift is plotted on the vertical F1 axis. The corresponding proton and 13C spectra are also shown. The HSQC contour plot does...
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 slanted or...

You might also read

Related Articles

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

Sort by
Same author

Mapping mRNA Localization and Internal Structure in Lipid Nanoparticles through Solid-State Dynamic Nuclear Polarization NMR and Proton Spin-Diffusion Modeling.

Small methods·2026
Same author

Fluorinated Biradicals for <sup>19</sup>F Magic-Angle Spinning Dynamic Nuclear Polarization-Enhanced NMR Spectroscopy.

Journal of the American Chemical Society·2026
Same author

Transforming solid-state nuclear magnetic resonance towards a chemistry-ready technique.

Solid state nuclear magnetic resonance·2025
Same author

Navigating infection by pathogenic spirochetes: The host-bacteria interface at the atomic level.

Protein science : a publication of the Protein Society·2025
Same author

Detection of Trichinella spp. in free-ranging carnivores and wild boars in Switzerland.

Veterinary parasitology·2025
Same author

<sup>1</sup>H-<sup>19</sup>F cross-polarization magic angle spinning dynamic nuclear polarization NMR investigation of advanced pharmaceutical formulations.

Journal of magnetic resonance (San Diego, Calif. : 1997)·2025

Related Experiment Video

Updated: May 27, 2026

Frequency Mixing Magnetic Detection Scanner for Imaging Magnetic Particles in Planar Samples
07:01

Frequency Mixing Magnetic Detection Scanner for Imaging Magnetic Particles in Planar Samples

Published on: June 9, 2016

MQD--multiplex-quadrature detection in multi-dimensional NMR.

Judith Schlagnitweit1, Michaela Horničáková, Gerhard Zuckerstätter

  • 1Institute of Organic Chemistry, Johannes Kepler University Linz, Altenberger Str. 69, 4040 Linz, Austria.

Chemphyschem : a European Journal of Chemical Physics and Physical Chemistry
|November 19, 2011
PubMed
Summary

Multiplex-quadrature detection (MQD) merges coherence selection and quadrature separation in N-dimensional heteronuclear NMR. This significantly reduces acquisition time and increases resolution without adjustable parameters.

More Related Videos

Nuclear Magnetic Resonance Spectroscopy for the Identification of Multiple Phosphorylations of Intrinsically Disordered Proteins
12:47

Nuclear Magnetic Resonance Spectroscopy for the Identification of Multiple Phosphorylations of Intrinsically Disordered Proteins

Published on: December 27, 2016

Related Experiment Videos

Last Updated: May 27, 2026

Frequency Mixing Magnetic Detection Scanner for Imaging Magnetic Particles in Planar Samples
07:01

Frequency Mixing Magnetic Detection Scanner for Imaging Magnetic Particles in Planar Samples

Published on: June 9, 2016

Nuclear Magnetic Resonance Spectroscopy for the Identification of Multiple Phosphorylations of Intrinsically Disordered Proteins
12:47

Nuclear Magnetic Resonance Spectroscopy for the Identification of Multiple Phosphorylations of Intrinsically Disordered Proteins

Published on: December 27, 2016

Area of Science:

  • Nuclear Magnetic Resonance (NMR) Spectroscopy
  • Analytical Chemistry
  • Biophysical Chemistry

Background:

  • N-dimensional heteronuclear NMR experiments require extensive acquisition time for coherence selection and quadrature separation.
  • Achieving high resolution in indirect dimensions often necessitates a large number of transients.
  • Current methods can be time-consuming and computationally intensive.

Purpose of the Study:

  • To introduce and validate multiplex-quadrature detection (MQD) for N-dimensional heteronuclear NMR.
  • To demonstrate the reduction in acquisition time and improvement in resolution offered by MQD.
  • To show that MQD achieves these benefits without adjustable parameters.

Main Methods:

  • Multiplex-quadrature detection (MQD) integrates coherence selection and quadrature separation.
  • MQD reduces the minimum number of transients per indirect data point by a factor of (3/4)(N-1).
  • The method was demonstrated using 3D HNCO and HCCH-TOCSY experiments.

Main Results:

  • MQD achieved the same spectral resolution and per-scan sensitivity as standard phase-cycled methods.
  • Acquisition time was reduced to 56% of the usual time for comparable spectra.
  • Improved resolution was observed within the same acquisition time compared to standard methods.

Conclusions:

  • MQD offers a significant advantage in terms of speed and resolution for N-dimensional heteronuclear NMR.
  • The technique streamlines data acquisition without compromising spectral quality.
  • MQD is a valuable advancement for NMR spectroscopy, particularly for complex molecular systems.