Solubility Determination of 4-Chlorobenzophenone in Sixteen Pure Solvents: Thermodynamic Correlations and Solvent Effect Analysis

Abstract The solubility behavior of 4-chlorobenzophenone (4-CBP) was measured in 16 pure solvents (eight alcohols, four ketones, three esters, and acetonitrile) from 271.95 to 324.05 K at atmospheric pressure. X-ray powder diffraction confirmed crystal stability during dissolution, while differential scanning calorimetry determined its melting properties. Five thermodynamic models (modified Apelblat, λh, NRTL, Wilson, and Yaws) were applied to correlate the solubility data. The Kamlet–Abboud–Taft model was introduced to decipher solvent effects by deconvoluting contributions from polarity and hydrogen-bonding. Fitting performance was evaluated using relative average deviation and root-mean-square deviation. Results show that the solubility of 4-CBP increases with rising temperature and that all five models provide satisfactory agreement with the experimental data. The KAT-LSER analysis reveals the dominant solvent parameters that govern solubility. Thermodynamic mixing properties derived from the Wilson model indicate that dissolution is spontaneous and entropy-driven. This study establishes a comprehensive solubility database for 4-CBP, providing critical thermodynamic evidence for the rational design of crystallization processes.