14N decoupling

N-Decoupling by double irradiation has also proved to be a very promising method for improving the resolution as well as for allowing the accurate determination of the signal of the N—H proton.30-42... 

From proton spectra by 14N decoupling, tickling, and simultaneous decoupling of substituent protons recalculated to 15N ref. 151. 

Those on a nitrogen (14N) atom are subject to partial or complete decoupling by the electrical quadrupole moment of the, 4N nucleus, whose spin number is one. 

C.-F. Hoelger, E. Rossler, B. Wehrle, F. Aguilar-Parrilla and H.-H. Limbach, Self-decoupling of 15N-14N dipole-quadrupole couplings in 15N CPMAS NMR spectra and molecular motions in crystalline hydrazine sulfate, p-(diethylamino)benzaldehyde, and its solid solution in polycarbonate.. Phys. Chem., 1995, 99,14271-14276. 

The INDOR technique of decoupling 14N from H (150) has been shown to yield two different values of /(N-H) in formamide, but the experimental errors are much larger than those found in the measurement of 13N-H couplings. 

In the simple CP/MAS experiment for 15N and 13C nuclei in a peptide, scalar coupling to H is not observed because high-power ]H decoupling is used to remove the H-15N or H-13C dipolar interactions. However, for the carbons directly bonded to nitrogens, 14N-13C or, 5N-,3C dipolar interactions are not averaged out by MAS and broadened asymmetric doublets are observed.14-17 Accord-... 

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