2H double-quantum MAS NMR spectroscopy as a probe of dynamics on the microsecond timescale in solids

The sidebands observed in the magic angle spinning (MAS) NMR spectrum of a spin I = 1 H-2 nucleus may be very strongly broadened if motion is present in the solid. The broadening arises from interference between the line-narrowing effects of MAS and the dynamics-driven reorientation of the H-2 quadrupole tensor. Here, we show that this motional broadening is absent or much reduced in the corresponding double-quantum MAS NMR spectrum. This observation suggests a new approach to studying dynamics in solids and examples are drawn from H-2 MAS NMR of oxalic acid dihydrate, sodium tetrathionate dihydrate, and the synthetic polymer PMMA. (c) 2006 Elsevier B.V. All rights reserved.