The hydrogen bonding dynamics and cooperative interactions in aqueous N,N-dimethyl formamide solution studied by dielectric relaxation spectroscopy

The values of dielectric constant for N,N-dimethylformamide(DMF)-water mixtures in entire mixing range have been determined in the frequency range 100 MHz-20 GHz at 298 K using the dielectric relaxation spectroscopy (DRS) method. The dielectric spectra of DMF-water mixture with an asymmetric shape are observed. The mixture behavior is described according to the Cole-Davidson model using four parameters (ε∞, ε0, τ and β). The number of hydrogen bonds between the water-water and DMF-water pairs is estimated from the values of the static dielectric constant by using the Luzar model. The model provides a satisfactory explanation of the experimental results related to the static dielectric constant. The hydrogen bond binding energies for water-water (pair 11) and DMF-water (pair 12) are estimated to be 13.01 and 13.10 kJ/mol, we report a new strategy to parameterize effective DMF-water cluster interactions to provide valuable insights into the underlying mechanism of the relaxation acts.