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Nitrogen-14 NMR Spectroscopy Using Residual Dipolar Splittings in Solids


Simone Cavadini, Adonis Lupulescu, Sasa Antonijevic,* and Geoffrey Bodenhausen

Laboratoire de Résonance Magnétique Biomoléculaire, Ecole Polytechnique Fédérale de Lausanne, Batochime, CH-1015 Lausanne, Switzerland, and Département de Chimie, associé au CNRS, Ecole Normale Supérieure, 24 rue Lhomond 75231, Paris Cedex 05, France

J. Am. Chem. Soc., 128 (24), 7706 -7707, 2006.

It is shown that nuclear magnetic resonance (NMR) spectra of nitrogen-14 (spin I = 1) can be obtained by indirect detection in powders spinning at the magic angle (MAS). The method relies on the transfer of coherence from a neighboring nucleus with S = 1/2, such as carbon-13, to single- or double-quantum transitions of nitrogen-14 nuclei. The transfer of coherence occurs through second-order quadrupole-dipole cross terms, also known as residual dipolar splittings. The two-dimensional NMR spectra reveal powder patterns determined by the second-order quadrupolar interactions of nitrogen-14. Analysis of the spectra yields the quadrupolar coupling constant, CQ, and asymmetry parameter, Q, of nitrogen-14. These parameters can be related to the structure of nitrogen-containing solids