Intradiffusion, density and viscosity studies in binary liquid systems of acetylacetone + DMF/DMSO/benzene at 303.15 K and 333.15 K

Intradiffusion coefficients of acetylacetone (AcAc) and DMF/DMSO/benzene in binary systems over the entire concentration range at 303.15 K were determined by 1H diffusion-order spectroscopy (DOSY) nuclear magnetic resonance (NMR) method based pulse field gradient (PFG). The densities and viscosities of the above three binary systems at 303.15 K were also studied and employed to calculate the excess molar volumes (VE) and deviations in viscosity (∆η). Besides, experiments were carried out at 333.15 K for the system of AcAc + DMF. The solvent and temperature effect upon the difference in D between enol and keto tautomers, the tautomeric equilibrium and excess properties (VE and ∆η) were discussed as well. Isotherms of VE as a function of mole fraction of AcAc (x1) show positive deviations in benzene but negative deviations in DMF and DMSO, whereas isotherms of ∆η as a function of x1 record positive deviations in DMF but negative in benzene and DMSO. VE values show more negative and ∆η values are less positive in the system of AcAc + DMF at 333.15 K compared to 303.15 K. The VE and ∆η were fitted to a Redlich–Kister type equation and the measured results were interpreted concerning molecular interactions in the solutions.

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