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

Abstract

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.