Concept

Solid-state nuclear magnetic resonance

Solid-state NMR (ssNMR) spectroscopy is a technique for characterizing atomic level structure in solid materials e.g. powders, single crystals and amorphous samples and tissues using nuclear magnetic resonance (NMR) spectroscopy. The anisotropic part of many spin interactions are present in solid-state NMR, unlike in solution-state NMR where rapid tumbling motion averages out many of the spin interactions. As a result, solid-state NMR spectra are characterised by larger linewidths than in solution state NMR, which can be utilized to give quantitative information on the molecular structure, conformation and dynamics of the material. Solid-state NMR is often combined with magic angle spinning to remove anisotropic interactions and improve the resolution as well as the sensitivity of the technique. The resonance frequency of a nuclear spin depends on the strength of the magnetic field at the nucleus, which can be modified by isotropic (e.g. chemical shift, isotropic J-coupling) and anisotropic interactions (e.g. chemical shift anisotropy, dipolar interactions). In a classical liquid-state NMR experiment, molecular tumbling coming from Brownian motion averages anisotropic interactions to zero and they are therefore not reflected in the NMR spectrum. However, in media with no or little mobility (e.g. crystalline powders, glasses, large membrane vesicles, molecular aggregates), anisotropic local fields or interactions have substantial influence on the behaviour of nuclear spins, which results in the line broadening of the NMR spectra. Chemical shift Chemical shielding is a local property of each nuclear site in a molecule or compound, and is proportional to the applied external magnetic field. The external magnetic field induces currents of the electrons in molecular orbitals. These induced currents create local magnetic fields that lead to characteristic changes in resonance frequency. These changes can be predicted from molecular structure using empirical rules or quantum-chemical calculations.

À propos de ce résultat
Cette page est générée automatiquement et peut contenir des informations qui ne sont pas correctes, complètes, à jour ou pertinentes par rapport à votre recherche. Il en va de même pour toutes les autres pages de ce site. Veillez à vérifier les informations auprès des sources officielles de l'EPFL.
Cours associés (8)
CH-601(x): Basic and advanced NMR - Level 1 A (EPFL)
Basic theoretical and experimental aspects of NMR will be taught. Students will be familarized with modern NMR spectrometers.
CH-601(y): Basic and advanced NMR - Level 1 B (Sion)
Basic theoretical and experimental aspects of NMR. Students will be familarized with modern NMR spectrometers.
CH-314: Structural analysis
The aim of this course is to treat three of the major techniques for structural characterization of molecules used in chemistry and chemical engineering: mass spectrometry, NMR, and X-ray techniques.
Afficher plus
Séances de cours associées (33)
RMN et quadripôles à l'état solide
Explore les principes de RMN à l'état solide, les changements chimiques anisotropes, les interactions quadripolaires et les techniques à haute résolution.
Spin Coherence: Cohérence quantique double
Explore l'écho spin, les échos quadrupolaires et la double cohérence quantique dans la dynamique des spins.
Techniques expérimentales: RMN & muSR
Explore les techniques expérimentales de RMN, y compris la résonance et le faible couplage dans les noyaux actifs de RMN.
Afficher plus
Publications associées (331)

A continuous-wave and pulsed X-band electron spin resonance spectrometer operating in ultra-high vacuum for the study of low dimensional spin ensembles

Giovanni Boero, Fabio Donati, Soyoung Oh

We report the development of a continuous-wave and pulsed X-band electron spin resonance (ESR) spectrometer for the study of spins on ordered surfaces down to cryogenic temperatures. The spectrometer operates in ultra-high vacuum and utilizes a half-wavele ...
Aip Publishing2024

129Xe Dynamic Nuclear Polarization Demystified: The Influence of the Glassing Matrix on the Radical Properties

Rolf Gruetter, Andrea Capozzi, Jean-Noël Hyacinthe, Thanh Phong Kevin Lê, Emma Linnea Wiström

129Xe dissolution dynamic nuclear polarization (DNP) is a controversial topic. The gold standard technique for hyperpolarized xenon magnetic resonance imaging (MRI) is spin exchange optical pumping, which received FDA approval in 2022. Nevertheless, the ve ...
2024

Multi-sample/multi-nucleus parallel polarization and monitoring enabled by a fluid path technology compatible cryogenic probe for dissolution dynamic nuclear polarization

Andrea Capozzi, Jean-Noël Hyacinthe, Thanh Phong Kevin Lê

Low throughput is one of dissolution Dynamic Nuclear Polarization (dDNP) main shortcomings. Especially for clinical and preclinical applications, where direct 13C nuclei polarization is usually pursued, it takes hours to generate one single hyperpolarized ...
2023
Afficher plus
Concepts associés (1)
Couplage scalaire
Le couplage scalaire, noté J et aussi appelé couplage dipôle-dipôle indirect ou juste couplage, est une interaction entre plusieurs spins à travers les liaisons chimiques. C'est une interaction indirecte entre deux spins nucléaires qui provient des interactions hyperfines entre les noyaux et la densité électronique locale et provoque un éclatement du signal RMN. Le couplage scalaire contient des informations sur la distance à travers les liaisons chimiques et les angles entre ces liaisons.
MOOCs associés (1)
Basic Steps in Magnetic Resonance
A MOOC to discover basic concepts and a wide range of intriguing applications of magnetic resonance to physics, chemistry, and biology

Graph Chatbot

Chattez avec Graph Search

Posez n’importe quelle question sur les cours, conférences, exercices, recherches, actualités, etc. de l’EPFL ou essayez les exemples de questions ci-dessous.

AVERTISSEMENT : Le chatbot Graph n'est pas programmé pour fournir des réponses explicites ou catégoriques à vos questions. Il transforme plutôt vos questions en demandes API qui sont distribuées aux différents services informatiques officiellement administrés par l'EPFL. Son but est uniquement de collecter et de recommander des références pertinentes à des contenus que vous pouvez explorer pour vous aider à répondre à vos questions.