H-2 NMR LINE-SHAPES AND SPIN-LATTICE RELAXATION IN BA(CLO3)(2)CENTER-DOT(H2O)-H-2

Solid-state deuterium NMR measurements were used to characterize the f lipping motion of the water molecule in barium chlorate monohydrate, B a(ClO3)(2) .(H2O)-H-2. In particular, temperature-dependent quadrupole echo line shapes, their tau dependence and spectral intensities, and the anisotropy of the spin-lattice relaxation observed in inversion re covery experiments permit measurement of the 2-fold flipping rates. Th ese were studied as a function of temperature and yield an activation energy E(a) = 30 kJ/mol and pre-exponential factor A(0) = 1.5 x 10(14) , which are typical for molecular motion constrained by hydrogen bonds of moderate strength. A discussion of experimental considerations is also presented.