Intradiffusion coefficients of acetylacetone (AcAc) and DMF/DMSO/benzene in binary systems over the entire concentration range at 303.15 K were determined by

1

H diffusion-order spectroscopy (DOSY) nuclear magnetic resonance (NMR)method based pulse field gradient (PFG). The densities and viscosities of the above three binary systemsat 303.15 Kwere also studied andemployed to calculate the excessmolar volumes (V

E

) and deviations in viscosity (Δη). Besides

experiments were carried out at 333.15 K for the systemof AcAc+DMF. The solvent and temperature effect upon the difference in D between enol and keto tautomers

the tautomeric equilibrium and excess properties (V

E

and Δη) were discussed as well. Isotherms of VE as a function of mole fraction of AcAc (x

1

) show positive deviations in benzene but negative deviations in DMF and DMSO

whereas isotherms of Δη as a function of x

1

record positive deviations in DMF but negative in benzene and DMSO. V

E

values show more negative and Δη values are less positive in the system of AcAc + DMF at 333.15 K compared to 303.15 K. The VE and Δη were fitted to a Redlich-Kister type equation and the measured results were i

nterpreted concerning molecular interactions in the solutions.