N-14 QUADRUPOLE RELAXATION OF DMF AND DMF-D(7) IN DMSO AT INFINITE DILUTION

The N-14 quadrupole relaxation time in pure DMF is by 9% longer than i n pure DMF-d(7), showing the dependence of the reorientational molecul ar motion on the square root of the moment of inertia. But for traces of DMF and DMF-d(7) in DMSO, the N-14 quadrupole relaxation time tends to obey the ''square-root-of-the-reduced-mass law'', as expected from the kinetic theory of dense fluids. The vanishing of the moment-of-in ertia effect on the intramolecular nuclear quadrupole relaxation is di scussed in terms of molecular translation-rotation coupling.