Molecular interaction in binary mixtures of 3-Bromoanisole and methanol: A microwave dielectric relaxation spectroscopy and molecular dynamic simulation study

Complex permittivity spectra for the binary mixtures of 3-bromoanisole (3-BA) and methanol (MeOH) with varying concentrations at different temperatures (T = 293.15 to 323.15 K) were obtained over a broad microwave frequency range. The complex permittivity data were fitted to different dielectric relaxation models using complex nonlinear least square fitting method. From the best fitting model dielectric relaxation parameters were extracted. Concentration dependence of the dielectric relaxation parameters were used to gain information about the molecular interaction among the constituent of the mixtures. The formation and deformation of H-bonds among the molecules of the mixture are discussed using wait-and-switch model. Temperature and concentration dependent static permittivity provided information about the alignment and cross-linkage of molecules in liquid mixtures. Molecular dynamics (MD) simulations of mixtures of 3-BA and MeOH at 293.15 K temperature have also been conducted to gain additive information regarding molecular interaction and to justify the inferences derived from the experimental microwave complex permittivity data.