Molecular interactions between the polar systems N-methyl aniline and alcohols (propan-1-ol/propan-2-ol) for various mole fractions at different temperatures are studied by determining the dielectric permittivity using LF impedance analyzer, Microwave bench and Abbe's refractometer in radio, microwave and optic frequency regions respectively. The dipole moment, excess dipole moment, excess Helmholtz energy, excess permittivity, excess inverse relaxation time and excess thermodynamic values are calculated using experimental results. The optimized geometry, harmonic vibrational wave numbers and dipole moments of pure and equimolar binary mixtures have been calculated theoretically from the ab initio Hartree-Fock (HF) and Density Functional Theory (DFT - B3LYP) methods with 6-31+G* and 6-311+G** basis sets using Spartan 08 modelling software. Conformational analysis of the formation of hydrogen bond in the equimolar binary mixture systems of N-methyl aniline and alcohols (propan-1-ol/propan-2-ol) is supported by experimental FT-IR spectra. The calculated wave numbers and dipole moments agree well with the experimental values. Further, the correlations among the parameters are discussed in detail. (C) 2011 Elsevier Ltd. All rights reserved.