Solubility Determination, Modeling, and Preferential Solvation of 1-(2-Bromophenyl)-pyrrole-2,5-dione in Aqueous Binary Mixtures of Isopropanol, Ethanol, N-Methyl-2-pyrrolidinone and Methanol

Abstract

Experimental determination of equilibrium solubility of 1-(2-bromophenyl)-pyrrole-2,5-dione in binary aqueous solutions containing a co-solvent of isopropanol, ethanol, N-methyl-2-pyrrolidinone (NMP) or methanol over temperatures from 278.15 to 323.15 K was made by the shake-flask technique under local pressure of 101.2 kPa. At the identical experimental conditions (temperature and mass fraction compositions of co-solvents), the maximum equilibrium solubility magnitude in a mole fraction of 1-(2-bromophenyl)-pyrrole-2,5-dione was recorded in the NMP (1) + water (2) system; and the minimum one, in the isopropanol (1) + water (2) system. The solvent effect was quantitatively analyzed by employing the KAT-LSER model, representing the solubility parameter and dipolarity–polarizability had main contributions to the solubility variation at 298.15 K. Four relationships, such as the Jouyban–Acree model, modified Wilson model, Jouyban–Acree–van’t Hoff model, and mixture response surface (MRS) model, were employed to correlate the determined solubility magnitudes, attaining the root-mean-square deviations of no higher than 493.0 × 10–5 and relative average deviations of no higher than 5.59%. The molecule interactions of solute–solvent and solvent–solvent were investigated through the extended Hildebrand solubility approach. In water-rich composition regions, there was some association between 1-(2-bromophenyl)-pyrrole-2,5-dione and solution. Furthermore, the local mole fractions of isopropanol (ethanol, NMP, or methanol) and water nearby 1-(2-bromophenyl)-pyrrole-2,5-dione were quantitatively evaluated by the inverse Kirkwood–Buff integrals. 1-(2-Bromophenyl)-pyrrole-2,5-dione was preferentially solvated by water in water-rich proportions; while in co-solvent-rich proportions for the solutions studied, it was preferentially solvated by isopropanol (ethanol, NMP, or methanol). In water-rich ranges, 1-(2-bromophenyl)-pyrrole-2,5-dione could be predominantly serving as a Lewis base in front of water molecules.