Journal of Chemical and Engineering Data, Vol.65, No.5, 2912-2920, 2020
Equilibrium Solubility Investigation and Preferential Solvation of 2,6-Dichloro-4-nitroaniline Dissolved in Four Aqueous Mixtures of Isopropanol, Acetonitrile, n-Propanol, and N-Methyl-2-pyrrolidone
Saturated solubilities of 2,6-dichloro-4-nitroaniline in aqueous mixtures of isopropanol, acetonitrile, n-propanol, and N-methyl-2-pyrrolidone (NMP) were examined via the shake-flask equilibrium method under atmospheric pressure (p= 101.2 kPa) and temperatures from (278.15 to 323.15) K. The mole fraction solubility increased with increasing temperature as well as mass fractions of isopropanol, acetonitrile, n-propanol, or NMP. The maximum solubility values appeared in neat organic solvents. van't Hoff-Jouyban-Acree and Jouyban-Acree models were employed to correlate the solubility data. The acquired values of relative average deviations and root-mean-square deviations were no more than 6.40 X 10(-2) and 56.49 x 10(-4), respectively. The local mole fractions of (isopropanol, acetonitrile, n-propanol, or NMP) and water around 2,6-dichloro-4-nitroaniline were quantitatively studied with the help of the inverse Kirkwood-Buff integrals technique. The preferential solvation parameters for 2,6-dichloro-4-nitroaniline presented positive in the isopropanol (acetonitrile, n-propanol, or NMP) mixtures within intermediate and isopropanol (acetonitrile, n-propanol, or NMP)-rich contents, which designated that the solute 2,6-dichloro-4-nitroaniline was preferentially solvated by the isopropanol (acetonitrile, n-propanol, or NMP). In these regions, 2,6-dichloro-4-nitroaniline might mainly serve as a Lewis acid interacting with proton-acceptor functional groups of isopropanol (n-propanol or NMP), while for the mixture of acetonitrile + water, the preferential solvation could be resulted from polarization effects.