Spin-lattice relaxation times and nuclear Overhauser enhancement factors (NOE) for the individual ring carbons in di-methyl phthalate (DMF) were measured over a wide range of temperatures. The results show that the reorientational correlation function corresponding to the global dynamics in supercooled liquid can be well described by a Davidson-Cole distribution. The viscosity dependence of the reorientational correlation time derived is analysed to investigate the adequacy of the modified Debye equation to description of the microscopic behaviour of supercooled systems.

The dynamics of the α-relaxation in a glass-forming low-molecular-weight system, di-isobutyl phthalate (DIBP), has been studied by means of dielectric, nuclear magnetic and mechanical spectroscopies. By using these techniques we have covered a wide timescale ranging from 10-11 to 102 s. Vogel-Fulcher correlation time behaviour and the Davidson-Cole distribution function make possible a simultaneous fitting of T1, the nuclear Overhauser enhancement (NOE) factor and dielectric data over the temperature range (Tg-4 K)

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The 13C nuclear spin‐lattice relaxation times for ring and methyl carbons in liquid 3,5‐lutydyne (3,5‐dimethylpyridine, 3,5‐DMP) have been measured as a function of temperature. The results have been analyzed in terms of two relaxation mechanisms: intramolecular dipole‐dipole coupling and spin‐rotation interaction. In order to separate these contributions, also the nuclear Overhauser enhancement factors have been studied. The results have been analyzed in terms of the theory of extended diffusion (ED) model for internal motion of methyl groups with a low barrier to internal rotation.