Solution-state cross-polarization for selective excitation of scalar-coupled quadrupolar nuclei S>1/2 in the presence of a residual quadrupolar splitting

Abstract

We show that solution-state cross-polarization in nuclear magnetic resonance is a valuable technique for the selective observation of scalar-coupled quadrupolar nuclei in anisotropic phases. Numerical simulations show that coherence transfer remains efficient provided the quadrupolar splitting is smaller than the scalar-coupling constant. The method is applied to a mixture of beryllium fluoride complexes. Despite severe overlap in the 9Be spectrum these results clearly demonstrate a quadrupolar splitting for BeF 3 − whereas no such splitting is resolved for BeF 4 2−.