CORRELATION OF DEUTERIUM QUADRUPOLAR TENSOR ORIENTATION VIA SPIN-DIFFUSION UNDER SLOW MAGIC-ANGLE SAMPLE-SPINNING

A two-dimensional H-2 spin-diffusion experiment for the characterizati on of solids is described. The experiment utilizes slow magic-angle sa mple spinning to enhance H-2 spin diffusion while the informative H-2 quadrupolar spin interactions are fully retained as in static samples. Energy-level crossing induced by slow sample rotation at the magic an gle enhances H-2 spin diffusion, and the polarization transfer becomes nearly frequency-independent even for large quadrupolar splittings. T he utility of the two-dimensional H-2 spin-diffusion experiment with s low magic-angle spinning is demonstrated by applications to deuterated crystalline samples. Accurate intra- and inter-molecular angular info rmation on the orientation of quadrupolar tensors is obtained from the measurements. (C) 1998 Elsevier Science B.V.