High resolution solid state 13C NMR spectra of carbons bonded to nitrogen in a sample spinning at the magic angle

Abstract

High resolution solid state 13C NMR spectra of amino acids and nitrile compounds have been obtained by a combination of cross-polarization, dipolar decoupling, and magic angle spinning techniques (CP–MAS). The resonances of Cα and cyano carbons in the observed 13C spectra show asymmetric doublet patterns. This problem has been treated by using the adiabatic approximation since the 14N quadrupole interaction is much larger than the spinning frequency. Theoretical spectra have been simulated for these carbons and they show very good agreement with experimental observations.