Study of short range and long range molecular interactions in binary liquid mixtures of N,N-dimethylformamide (DMF) and 1-propanol

Abstract

In the present study precisely measured properties; static dielectric constant (ε0), refractive index (n) and density (ρ) of binary liquid mixtures of N,N-dimethylformamide (DMF) and 1-propanol (1-PN) have been used to determine linear correlation parameter (grr), mutual linear correlation parameter (gAB), excess Helmholtz free energy functions (ΔF) and excess molar polarization (ΔP). The dipolar contributions to these functions arising from long range electrostatic interaction, short range interaction between identical molecules and short range interaction between dissimilar molecules have been assessed separately. The excess thermodynamic functions calculated from the experimental data supports the formation of clusters with antiparallel or destructive angular correlation (β-clusters). The variation of excess static dielectric constant, excess refractive index and excess molar volume have been used to discuss the type, the strength and the nature of intermolecular interactions betweenconstituent species. Comparison of the predicted values of static dielectric constant and refractive index of the liquid mixtures using various mixing rules with the experimentally determined values have been assessed in terms of Average Percentage Deviation (APD).