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Optimizing the13C–14N REAPDOR NMR Experiment: A Theoretical and Experimental Study

✍ Scribed by Yong Ba; Hsien-Ming Kao; Clare P. Grey; Lamy Chopin; Terry Gullion

Publisher
Elsevier Science
Year
1998
Tongue
English
Weight
251 KB
Volume
133
Category
Article
ISSN
1090-7807

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✦ Synopsis

The optimum 14 N pulse lengths in the 13 C-14 N rotationalecho adiabatic-passage double-resonance (REAPDOR) NMR experiment are determined from calculations and from experiments on samples of glycine and L-alanine. The REAPDOR experiment utilizes the adiabatic passages that 14 N spins make between the 14 N Zeeman energy levels during the application of a single, short 14 N radiofrequency pulse. Use of a short 14 N irradiation time of less than one-quarter of a rotor period ensures that the number of 14 N spins that undergo more than one passage is minimized. This simplifies calculations describing 13 C dipolar dephasing and provides better agreement between calculations and experiments. Recovery of the 13 C-14 N dipolar couplings and 14 N quadrupolar coupling constants and asymmetry parameters is described.

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