Experimental and theoretical investigation of thermodynamic properties and hydrogen bonding strength of binary mixtures: Insights from FTIR and DFT calculation

Present study reveals that experimental measurements of density (rho), sound speed (u) of binary mixtures of o-toluidine with 1-propanol, 1-butanol, 1-pentanol, 1-hexanol, 1-heptanol, 1-octanol and 1-nonanol were measured at T=298.15 K and P=0.1 MPa. The rho and u data was intern used to calculate the various thermodynamic properties. The attained results were used to understand the nature of interaction between like and unlike molecules in terms of hydrogen bonding, dipoledipole interactions and packing efficiency. The derived excess properties were fitted into polynomial equations. The resultant VE magnitude gradually changes from negative sign to positive sign through the formation of 'S' type curve. The formation of hydrogen bonding and strength between the component molecules were confirmed by FTIR spectroscopy and DFT computational study, respectively. The results of the experimental and derived thermodynamic properties are good agreement with DFT theoretical model.