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

¹H NMR: Complex Splitting01:13

¹H NMR: Complex Splitting

1.7K
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...
1.7K
¹H NMR: Interpreting Distorted and Overlapping Signals01:02

¹H NMR: Interpreting Distorted and Overlapping Signals

1.3K
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...
1.3K
¹³C NMR: Distortionless Enhancement by Polarization Transfer (DEPT)01:20

¹³C NMR: Distortionless Enhancement by Polarization Transfer (DEPT)

1.3K
When proton-coupled carbon-13 spectra are simplified by a broadband proton decoupling technique, structural information about the coupled protons is lost. Distortionless enhancement by polarization transfer (DEPT) is a technique that provides information on the number of hydrogens attached to each carbon in a molecule. While the DEPT experiment utilizes complex pulse sequences, the pulse delay and flip angle are specifically manipulated. The resulting signals have different phases depending on...
1.3K
2D NMR: Heteronuclear Single-Quantum Correlation Spectroscopy (HSQC)01:19

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

1.3K
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...
1.3K
¹H NMR of Conformationally Flexible Molecules: Variable-Temperature NMR01:15

¹H NMR of Conformationally Flexible Molecules: Variable-Temperature NMR

1.3K
The axial and equatorial protons in cyclohexane can be distinguished by performing a variable-temperature NMR experiment. In this process, except for one proton, the remaining eleven protons are replaced by deuterium. The deuterium substitution avoids the possible peak splitting caused by the spin-spin coupling between the adjacent protons. The remaining proton flips between the axial and equatorial positions.
1.3K
Interpreting ¹H NMR Signal Splitting: The (n + 1) Rule01:10

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

2.8K
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...
2.8K

You might also read

Related Articles

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

Sort by
Same author

Structural Significance and Reference Value of High-Precision Coupling Constants and Raw Data Sharing.

Analytical chemistry·2026
Same author

There is No Caffeine in Damiana-Dismantling Filter Bubbles and Echo Chambers in Scientific Referencing.

Planta medica·2026
Same author

Multilevel Residual Complexity Analysis Reveals Origin of Nanomolar Antiviral Bioactives of "Isoquercitrin".

Journal of natural products·2026
Same author

Long-term nano-dynamic mechanical analysis and micro-permeability of adhesive interface components using four AB-type proanthocyanidin neutral primers.

Journal of dentistry·2026
Same author

NMR-Based Quantification of Collagen Content in Protein Hydrolysates.

Journal of agricultural and food chemistry·2026
Same author

Discovery of Suomilide and Cyanopeptolin Analogues by <sup>15</sup>N Stable Isotope Labeling and Genome Mining of Cyanobacteria.

Journal of natural products·2026

Related Experiment Video

Updated: Apr 28, 2026

Structure and Coordination Determination of Peptide-metal Complexes Using 1D and 2D 1H NMR
14:44

Structure and Coordination Determination of Peptide-metal Complexes Using 1D and 2D 1H NMR

Published on: December 16, 2013

9.3K

Essential parameters for structural analysis and dereplication by (1)H NMR spectroscopy.

Guido F Pauli1, Shao-Nong Chen, David C Lankin

  • 1Department of Medicinal Chemistry and Pharmacognosy, College of Pharmacy, University of Illinois at Chicago , Chicago, Illinois 60612, United States.

Journal of Natural Products
|June 5, 2014
PubMed
Summary

Reporting nuclear magnetic resonance (NMR) data with high precision is crucial for accurate chemical structure elucidation and reproducibility. Enhanced precision in NMR spectroscopic analysis ensures reliable dereplication and metabolomic studies.

More Related Videos

Line Shape Analysis of Dynamic NMR Spectra for Characterizing Coordination Sphere Rearrangements at a Chiral Rhenium Polyhydride Complex
10:52

Line Shape Analysis of Dynamic NMR Spectra for Characterizing Coordination Sphere Rearrangements at a Chiral Rhenium Polyhydride Complex

Published on: July 27, 2022

2.8K
Atomic Scale Structural Studies of Macromolecular Assemblies by Solid-state Nuclear Magnetic Resonance Spectroscopy
14:55

Atomic Scale Structural Studies of Macromolecular Assemblies by Solid-state Nuclear Magnetic Resonance Spectroscopy

Published on: September 17, 2017

16.8K

Related Experiment Videos

Last Updated: Apr 28, 2026

Structure and Coordination Determination of Peptide-metal Complexes Using 1D and 2D 1H NMR
14:44

Structure and Coordination Determination of Peptide-metal Complexes Using 1D and 2D 1H NMR

Published on: December 16, 2013

9.3K
Line Shape Analysis of Dynamic NMR Spectra for Characterizing Coordination Sphere Rearrangements at a Chiral Rhenium Polyhydride Complex
10:52

Line Shape Analysis of Dynamic NMR Spectra for Characterizing Coordination Sphere Rearrangements at a Chiral Rhenium Polyhydride Complex

Published on: July 27, 2022

2.8K
Atomic Scale Structural Studies of Macromolecular Assemblies by Solid-state Nuclear Magnetic Resonance Spectroscopy
14:55

Atomic Scale Structural Studies of Macromolecular Assemblies by Solid-state Nuclear Magnetic Resonance Spectroscopy

Published on: September 17, 2017

16.8K

Area of Science:

  • Analytical Chemistry
  • Organic Chemistry
  • Spectroscopy

Background:

  • Proton nuclear magnetic resonance (¹H NMR) spectroscopy is vital for structure elucidation and verification of organic molecules.
  • Complex ¹H NMR spectra often present challenges in interpretation due to limited spectral dispersion and higher-order effects.
  • Reproducibility of spectral data is essential for chemical structure elucidation and dereplication.

Purpose of the Study:

  • To demonstrate the importance of adequate precision when reporting NMR data (δ and J parameters).
  • To rationalize the need for enhanced precision in NMR spectroscopic analysis for reliable dereplication and metabolomic studies.
  • To highlight the role of spectral simulations and iteration in complete spectral interpretation.

Main Methods:

  • Utilized a variety of structural classes including terpenoids, phenolics, and alkaloids from diverse taxa (plants, cyanobacteria).
  • Employed spectral simulations paired with iteration for complete spectral interpretation and precision enhancement.
  • Focused on reporting chemical shift (Δδ) and coupling constant (ΔJ) values at the 0.1-1 ppb and 10 mHz levels, respectively.

Main Results:

  • Established rationales for the importance of enhanced precision in NMR spectroscopic analysis.
  • Demonstrated that spectral simulations and iteration are essential for accurate spectral interpretation and unambiguous dereplication.
  • Showcased the critical role of precise HNMR data in linking chemical structure to analytical data, metabolomes, and biological activity.

Conclusions:

  • Adequate precision in reporting ¹H NMR data (δ and J parameters) is critical for reliable chemical analysis.
  • Enhanced precision facilitates unambiguous HNMR-driven dereplication and metabolomic analysis.
  • Precise handling and documentation of ¹H NMR data are essential for the reproducibility of studies involving bioactive chemicals.