Mj. Brown et al., SELECTIVE INVERSION INVESTIGATIONS OF SLOW MOLECULAR-MOTION IN SOLID-STATE DEUTERON NMR-SPECTROSCOPY, Solid state nuclear magnetic resonance, 6(2), 1996, pp. 167-185
Deuteron selective inversion experiments are reported for polycrystall
ine dimethyl sulfone-d(6) as a function of temperature from 288 to 333
K. Double sideband modulation was used to achieve efficient off-reson
ance orientation-selective inversion. Fitting the selective inversion-
recovery curves to two-site jump equations yields the motional rate. T
emperature dependent jump rates, obtained from both selective inversio
n and deuteron quadrupole echo lineshapes, give an activation energy E
(a) = 86.5 +/- 1.4 kJ mol(-1) and a frequency factor In(A)= 39.2 +/- 0
.5. These values differ significantly from those of earlier C-13 lines
hape studies. At 298 K, variable power excitation was used to determin
e the underlying orientation dependent homogeneous linewidth, which is
predominantly dipolar. The temperature dependence of the homogeneous
linewidth is a sensitive indicator of large angle jump motion in the r
ange 10(3)-10(4) s(-1).