Related Experiment Video
Updated: Jul 12, 2025
14:55
Atomic Scale Structural Studies of Macromolecular Assemblies by Solid-state Nuclear Magnetic Resonance Spectroscopy
Published on: September 17, 2017
15.5K
Solid-state 1H spin polarimetry by 13CH3 nuclear magnetic resonance
Stuart J Elliott1,2, Quentin Stern1, Sami Jannin1
1Centre de Résonance Magnétique Nucléaire à Très Hauts Champs - FRE 2034 Université de Lyon/CNRS/Université Claude Bernard Lyon 1/ENS de Lyon, 5 Rue de la Doua, 69100 Villeurbanne, France.
Magnetic Resonance (Gottingen, Germany)
|October 31, 2023
Summary
Dissolution dynamic nuclear polarization (DDNP) enables high nuclear spin polarization. This study shows [2-13C]sodium acetate
Area of Science:
- Solid-state Nuclear Magnetic Resonance (NMR) spectroscopy
- Dynamic Nuclear Polarization (DNP)
Background:
- Dissolution dynamic nuclear polarization (DDNP) prepares high nuclear spin polarizations.
- Quantifying proton (1H) polarization in solids is challenging due to the need for thermal equilibrium signals.
- Line shape analysis of solid-state NMR spectra can reveal spin system properties.
Purpose of the Study:
- To present a method for indirectly evaluating proton polarization using 13C spectral line shape analysis.
- To assess the utility of [2-13C]sodium acetate as a polarization indicator in DDNP experiments.
Main Methods:
- Analysis of the 13C spectral line shape of [2-13C]sodium acetate.
- Measurement of the normalized deviation of the center of gravity of 13C peaks.
- Correlation of 13C line shape characteristics with proton polarization.
Main Results:
- The normalized deviation of the 13C peak's center of gravity correlates with proton polarization.
- Increased proton polarization was observed with increasing normalized center of gravity deviation under positive microwave irradiation.
- [2-13C]sodium acetate can indirectly gauge proton polarization in homogeneous samples.
Conclusions:
- [2-13C]sodium acetate serves as a reliable dopant for indirect proton polarization measurement in DDNP.
- This method is advantageous for samples lacking 1H hardware or affected by radiation damping/background signals.
- It provides a feasible alternative when thermal equilibrium spectra acquisition is not possible.
Related Concept Videos
01:04¹³C NMR: ¹H–¹³C Decoupling
1.1K
The probability of having two carbon-13 atoms next to each other is negligible because of the low natural abundance of carbon-13. Consequently, peak splitting due to carbon-carbon spin-spin coupling is not observed in spectra. However, protons up to three sigma bonds away split the carbon signal according to the n+1 rule, resulting in complicated spectra.
A broadband decoupling technique is used to simplify these complex, sometimes overlapping, signals. Broadband decoupling relies on a...
A broadband decoupling technique is used to simplify these complex, sometimes overlapping, signals. Broadband decoupling relies on a...
1.1K
01:08NMR Spectroscopy: Spin–Spin Coupling
1.4K
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...
1.4K
01:03Atomic Nuclei: Nuclear Spin State Overview
975
NMR-active nuclei have energy levels called 'spin states' that are associated with the orientations of their nuclear magnetic moments. In the absence of a magnetic field, the nuclear magnetic moments are randomly oriented, and the spin states are degenerate. When an external magnetic field is applied, the spin states have only 2 + 1 orientations available to them. A proton with = ½ has two available orientations. Similarly, for a quadrupolar nucleus with a nuclear spin value of...
975
01:02¹H NMR: Interpreting Distorted and Overlapping Signals
1.0K
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...
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...
1.0K
01:10Carbon-13 (¹³C) NMR: Overview
5.7K
Carbon-13 is a naturally occurring NMR-active isotope of carbon with a low natural abundance of 1.1%. In contrast, carbon-12 is the most abundant isotope of carbon with zero nuclear spin. Therefore, it is NMR inactive. The gyromagnetic ratio of carbon-13 is smaller than that of protons. As a result, carbon-13 resonance is about 6000 times weaker than proton resonance. For a given magnetic field strength, the resonance frequency of carbon-13 is about one-fourth of the resonance frequency for...
5.7K
01:192D NMR: Heteronuclear Single-Quantum Correlation Spectroscopy (HSQC)
729
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...
729