JMR: Bodenhausen, indirect detection of 14N via 1H (HMQC type experiment)

Journal of Magnetic Resonance
Vol: 182 Issue: 1, September, 2006
Communication

Indirect detection of nitrogen-14 in solids via protons by nuclear magnetic resonance spectroscopy

Simone Cavadini a, Sasa Antonijevic a, , Email Address, Adonis Lupulescu a, Geoffrey Bodenhausen a, b
a Laboratoire de Résonance Magnétique Biomoléculaire, Institut des Sciences et Ingénierie Chimiques, Ecole Polytechnique Fédérale de Lausanne, Batochime, CH-1015 Lausanne, Switzerland
b Département de Chimie, associé au CNRS, Ecole Normale Supérieure, 24 rue Lhomond 75231, Paris Cedex 05, France

Abstract
This Communication describes the indirect detection of 14 N nuclei (spin I = 1) in solids by nuclear magnetic resonance (NMR) spectroscopy. The two-dimensional correlation method used here is closely related to the heteronuclear multiple quantum correlation (HMQC) experiment introduced in 1979 to study molecules in liquids, which has recently been used to study solids spinning at the magic angle. The difference is that the coherence transfer from neighboring 1 H nuclei to 14 N is achieved via a combination of J couplings and residual dipolar splittings (RDS). Projections of the two-dimensional correlation spectra onto the 14 N dimension yield powder patterns which reflect the 14 N quadrupolar interaction. In contrast to the indirect detection of 14 N via 13 C nuclei that was recently demonstrated [Gan, J. Am. Chem. Soc. 128 (2006) 6040; Cavadini et. al., J. Am. Chem. Soc., 128 (2006) 7706], this approach may benefit from enhanced sensitivity, and does not require isotopic enrichment in 13 C, although the 1 H line-widths may have to be reduced upon selective deuteration.