Experimental determination and prediction of the solubility of alpha-(trichloromethyl) benzyl acetate in monosolvents and binary mixed solvents

Abstract

The solid-liquid phase equilibrium of alpha-(Trichloromethyl) benzyl acetate (crystal rose) was investigated from structure and thermodynamic properties in both solid and solution phases. The Hirshfeld analysis of crystal rose reveals the dominant hydrophobic interactions in the crystal structure. The solution equilibrium solubility of crystal rose was measured by static method at atmospheric pressure from 288.15 K to 328.15 K in nine monosolvents and binary solvent mixtures of (ethanol + ethyl acetate). Solubility data were well correlated by the modified Apelblat model, van't Hoff equation and NRTL model, and the modified Apelblat equation achieved the best fitting performance. Furthermore, the mixing thermodynamic functions (enthalpy, entropy, and Gibbs energy) were derived, and the results suggest a spontaneous and entropy-driven mixing process in monosolvents. Finally, solubility prediction and intermolecular interactions in solution phase were performed by COSMO-RS model. The qualitative agreement between solubility prediction and experimental data was obtained in regard to the temperature-dependent solubility trend, but the derivations do exist and vary with the structure of solvents. The predicted solubility data are in good agreement with experimental ones in esters; nevertheless, the prediction displays overestimation in alcohols and acetone and underestimation in acetic acid and acetonitrile. The solubility data, thermodynamic models and thermodynamic functions presented in this study are valuable for purification and crystallization of crystal rose.