Excess enthalpies of binary solvent mixtures of N,N-dimethylacetamide with aliphatic alcohols

The excess enthalpies H_m^E of binary solvent mixtures of N,N-dimethylacetamide with methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, and t-butanol have been measured with a flow microcalorimeter at 40°C. The excess enthalpies increase as the length of the alkyl chain of the primary alcohol increases. The values for methanol are negative, those for ethanol change sign, and those for 1-propanol, and more clearly those for 1-butanol, are positive. The mixtures of the secondary and the tertiary alcohol exhibit mainly positive values of H_m^E. Solute-solute and solute-solvent interactions in these mixtures are discussed on the basis of the results.