Solubility Measurement and Calculation of Difenoconazole in Several Solvents at 278.15 to 323.15 K

The equilibrium solubility (mole fraction) of difenoconazole in methanol, ethanol, n-propanol, isopropanol, N,N-dimethylformamide (DMF), acetonitrile, acetone, propylene glycol (PG), ethylene glycol (EG), and water and methanol/ethanol/isopropanol/PG + water was measured by isothermal saturation method at 278.15–323.15 K under 101.2 kPa. The solubility of difenoconazole in pure solvents increased with increasing temperature, and the solubility in mixed solvents was proportional to the temperature and the ratio of cosolvents. The solubility of difenoconazole in pure solvents was correlated with the Apelblat, NRTL, and λh models. The Jouyban-Acree (JA), modified Apelblat-Jouyban-Acree (AJA), and van’t Hoff-Jouyban-Acree (VJA) models were applied to calculate the solubility of difenoconazole in mixtures. Solvent effect analysis as a powerful tool was used to estimate solvent–solvent and solvent–solute interactions at the molecular level, and the results showed that nonspecific dipolarity/polarizability interactions were the main influencing factor.