INTERNAL STRUCTURES OF LIQUID N,N-DIMETHYLFORMAMIDE-FORMAMIDE BINARY-MIXTURES

The H-1-NMR spectra of liquid binary mixtures of formamide (F) and N,N -dimethylformamide (DMF), were recorded at 298 K over almost the whole range of the mixed solvent compositions. From these data were found t he values of the spectral parameter, Delta delta(F-DMF). The densities (d(12)), viscosities (eta(12)) of the mixed solvent were measured at 298.15 K, as well as the relative permittivities (epsilon(12)) at 288. 15 K, 293.15 K and 303.15 K. From all these data, the molar volumes (V -12) and their deviations from ideality were calculated. Additionally, the temperature coefficients of relative permittivity, alpha(12) at 2 98.15 K were found. These structural parameters as functions of concen tration suggest the formation of stable 2F . 3DMF,F . DMF,3F . 2DMF an d 2F . DMFx type complexes.