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Magnetization transfer NMR study of nitrogen inversion in 2,2-dimethylaziridine

✍ Scribed by Eric R. Johnston


Publisher
John Wiley and Sons
Year
1995
Tongue
English
Weight
411 KB
Volume
33
Category
Article
ISSN
0749-1581

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✦ Synopsis


Abstract

The slow inversion at pyramidal nitrogen in 2,2‐dimethylaziridine was investigated by NMR spectroscopy at 304 K using one‐dimensional spin locking methods and two‐dimensional exchange spectroscopy. The activation free energy was found to be 17.5 kcal mol^−1^ (73.2 kJ mol^−1^) at this temperature. This value represents a lower limit for the unimolecular inversion barrier height as autocatalytic and water‐catalyzed inversion pathways can in principle also contribute to the observed rate. The spin locking experiments described employ non‐selective pulses and are particularly useful for the quantitative study of slow chemical exchange between nuclei of similar resonance frequency where selective magnetization transfer experiments are difficult or impossible.


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