Journal of Chemical and Engineering Data, Vol.65, No.5, 2683-2693, 2020
3-Bromo-4-hydroxybenzaldehyde in Aqueous Cosolvent Mixtures of Acetonitrile, Ethanol, n-Propanol, and N,N-Dimethylformamide: Solubility, Preferential Solvation, and Solvent Effect Analysis
Solubility data determination of 3-bromo-4-hydroxybenzaldehyde in aqueous cosolvent solutions of ethanol, acetonitrile, N,N-dimethylformamide (DMF), and n-propanol at the temperatures ranging from 278.15 to 323.15 K was performed using a shake-flask method under the pressure of 101.2 kPa. At the identical investigated temperature and mass fractions of cosolvents, the solubility of 3-bromo-4-hydroxybenzaldehyde in mole fraction scale was maximum in the mixture of DMF (1) + water (2) and minimum in the mixture of acetonitrile (1) + water (2). The solubility of 3-bromo-4-hydroxybenzaldehyde correlated very well by means of the Jouyban-Acree model. The root-mean-square deviations were no greater than 4.22 x 10(-4), and the relative average deviations were no greater than 3.35%. The local mole fractions of water and n-propanol (DMF, acetonitrile, or ethanol) nearby the solute 3-bromo-4-hydroxybenzaldehyde were calculated quantitatively by the method of inverse Kirkwood-Buff integrals. 3-Bromo-4-hydroxybenzaldehyde was preferentially solvated by water in water-rich contents, while within intermediate and cosolvent-rich contents for these mixtures, it was preferentially solvated by n-propanol (ethanol or acetonitrile) in the n-propanol (ethanol or acetonitrile) + water solutions. In addition, the solvent effect was explained by taking into consideration the model of Kamlet and Taft linear solvation energy relationships, and the relative significance of the interactions of solute-solvent and solvent-solvent molecules was distinguished. The changes in interaction energy of solvent-solvent molecules described by the cavity term were responsible for the solubility variation of 3-bromo-4-hydroxybenzaldehyde in all the studied solutions.