Multinuclear Residual Quadrupolar Couplings for Structure and Assignment

Abstract

Most stable isotopes have a nuclear spin >1/2, but the quadrupole interaction poses challenge on their detection by nuclear magnetic resonance (NMR). On the other hand, the quadrupole interaction is a rich source of structural information that may be exploited for solution NMR in the form of residual quadrupolar couplings (RQCs) of weakly oriented samples. While ²H RQCs are now well established for structure verification and enantiomeric discrimination of organic molecules, we will in this article highlight some recent work on RQCs of other nuclei (especially ⁷Li and ¹¹B).

Keywords: NMR spectroscopy; boron; electric field gradient; lithium; quadrupole coupling.