Methoden der Festk��rper-NMR-Spektroskopie in der Chemie

Abstract

A. Jerschow et al. und 29 Si. Wir behandeln daher zun‰chst die Spinwechselwirkungen, die bei solchen Kernen eine Rolle spielen, und stellen spektroskopische Methoden vor, mit denen sich diese Wechselwirkungen zur Vereinfachung der Spektren beeinflussen oder gar ausschalten lassen.In einem einfachen Beispiel wird eine w‰ssrige Lˆsung von 1-13 C-markiertem (10 %) Glycin mit einem p/2-Einzelpuls der Resonanzfrequenz von 13 C-Kernen bestrahlt. In dem resultierenden Spektrum (Abbildung 1) beobachtet man zwei gut aufgelˆste Signale, die den 13 C-angereicherten Carbonyl-C-Atomen und den in nat¸rlicher Isotopenverteilung (ca. 1 % 13

Local Ordering in the Intermetallic Compound Cu1-xAl2 Studied by NMR Spectroscopy

“…Nuclear magnetic resonance experiments give valuable information of the environments of the atoms either by the signals or more detailed by the internuclear couplings . Two earlier NMR investigations, focusing only on the line shapes of the signals, report a second resonance for Cu in Cu 1 - x Al 2 .…”

Rapid Natural‐Abundance 2D 13C–13C Correlation Spectroscopy Using Dynamic Nuclear Polarization Enhanced Solid‐State NMR and Matrix‐Free Sample Preparation

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Solid-state nuclear magnetic resonance (SSNMR) has been extensively used to characterize molecular structures at atomic scales. [1] Concerning biomolecular applications, structural studies are commonly performed on 13 C and/or 15 N enriched samples to compensate for their low natural abundance (1.11 % for 13 C and 0.37 % for 15 N). However, this strategy is mainly restricted to biomolecules that can be easily isotopically enriched and has proven difficult to expand to other types of systems.To date, only a few examples of natural abundance (NA) 2D 13 C-13 C correlation experiments in solids have been reported using pulse sequences that rely on through-bond polarization transfer.

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Rapid Natural‐Abundance 2D 13C–13C Correlation Spectroscopy Using Dynamic Nuclear Polarization Enhanced Solid‐State NMR and Matrix‐Free Sample Preparation

“…Solid‐state nuclear magnetic resonance (SSNMR) has been extensively used to characterize molecular structures at atomic scales 1. Concerning biomolecular applications, structural studies are commonly performed on 13 C and/or 15 N enriched samples to compensate for their low natural abundance (1.11 % for 13 C and 0.37 % for 15 N).…”