Related Experiment Video
Updated: May 16, 2026
13:16
Pure Shift Nuclear Magnetic Resonance: a New Tool for Plant Metabolomics
Published on: July 31, 2021
Improved SABRE hyperpolarisation using pulse sequences to reduce effective coupling
Vitaly P Kozinenko1, Bogdan A Rodin1, James Eills2
1NVision Imaging Technologies GmbH, Wolfgang-Paul Straße 2, 89081 Ulm, Germany. stephan@nvision-imaging.com.
Physical Chemistry Chemical Physics : PCCP
|May 14, 2026
Summary
Researchers slowed down polarization transfer in Signal Amplification by Reversible Exchange (SABRE) NMR, achieving improved performance. This method enhances polarization yield in specific SABRE systems, offering new possibilities for high-repeatability studies.
Area of Science:
- Nuclear Magnetic Resonance (NMR) Spectroscopy
- Quantum Chemistry
- Chemical Physics
Background:
- Signal Amplification by Reversible Exchange (SABRE) is a hyperpolarization technique enabling enhanced NMR sensitivity.
- Conventional SABRE methods prioritize rapid polarization transfer for optimal efficiency.
- Understanding the dynamics of polarization transfer is crucial for optimizing SABRE performance.
Purpose of the Study:
- To investigate the effect of slowed polarization transfer on SABRE efficiency.
- To explore novel NMR sequences for controlling polarization transfer rates.
- To identify conditions under which slower transfer enhances polarization yield.
Main Methods:
- Development and application of specialized NMR sequences designed to decelerate polarization transfer.
- Computational simulations to model polarization dynamics in SABRE systems.
- Analysis of polarization yield under varying magnetic inequivalence and substrate exchange rates.
Main Results:
- Slower polarization transfer, contrary to typical approaches, demonstrated improved performance in SABRE.
- Simulations confirmed enhanced polarization yield with slower transfer under specific conditions.
- Optimal performance was observed when hydride protons had strong magnetic inequivalence and substrates exchanged slowly.
Conclusions:
- Decelerating polarization transfer can be a viable strategy to improve SABRE performance.
- The findings offer a new perspective on optimizing hyperpolarization techniques.
- This approach holds potential for advancing high-repeatability studies in NMR spectroscopy.
Related Concept Videos
01:12Double Resonance Techniques: Overview
Double resonance techniques in Nuclear Magnetic Resonance (NMR) spectroscopy involve the simultaneous application of two different frequencies or radiofrequency pulses to manipulate and observe two distinct nuclear spins. One important application of double resonance is spin decoupling, which selectively suppresses coupling with one type of nucleus while observing the NMR signal from another nucleus, simplifying the spectrum and enhancing resolution.
Spin decoupling is usually achieved by...
Spin decoupling is usually achieved by...
01:15Insensitive Nuclei Enhanced by Polarization Transfer (INEPT)
Insensitive Nuclei Enhanced by Polarization Transfer (INEPT) is an advanced Nuclear Magnetic Resonance (NMR) technique specifically designed to detect and enhance the signals of low-abundance nuclei, such as carbon-13 and nitrogen-15, in small molecules. The fundamental principle behind INEPT is the transfer of polarization from a more abundant and highly polarizable nucleus, typically hydrogen-1, to the low-abundance nucleus of interest. This process effectively boosts the NMR signal of the...
01:20¹³C NMR: Distortionless Enhancement by Polarization Transfer (DEPT)
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...
01:17NMR Spectrometers: Radiofrequency Pulses and Pulse Sequences
A pulse is a short burst of radio waves distributed over a range of frequencies that simultaneously excites all the nuclei in the sample. Upon passing a radio frequency pulse along the x-axis, the nuclei absorb energy corresponding to their Larmor frequencies and achieve resonance. This shifts the net magnetization vector from the z-axis toward the transverse plane. This angle of rotation of the magnetization vector, or the flip angle, is proportional to the duration and intensity of the pulse.
01:04¹³C NMR: ¹H–¹³C Decoupling
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...
01:08NMR 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 in...