Solubility Measurement and Thermodynamic Modeling of 4-Nitrophthalimide in Twelve Pure Solvents at Elevated Temperatures Ranging from (273.15 to 323.15) K

Abstract

The solubility of 4-nitrophthalimide in different solvents are of great importance for the design of its purification process via crystallization. The work reported new solubility data for 4-nitrophthalimide in 12 pure solvents of methanol, ethanol, isopropanol, cyclohexanone, acetone, acetonitrile, ethyl acetate, 2-butanone, chloroform, 1,4-dioxane benzyl alcohol and N,N-dimethylformamide. They were determined by a high-performance liquid chromatography at T = (273.15 to 323.15) K under pressure of 0.1 MPa. The 4-nitrophthalimide solubility in the selected solvents increased with the temperature increase. At a given temperature, the solubility of 4-nitrophthalimide is largest in N,N-dimethylformamide and lowest in chloroform. The solubility data in the these solvents ranked as N,N-dimethylformamide > cyclohexanone > (1,4-dioxane, acetone, 2-butanone, benzyl alcohol) > ethyl acetate > acetonitrile > methanol > ethanol > isopropanol > chloroform. The experimental solubility data were correlated by modified Apelblat equation, λh equation, Wilson model, and NRTL model. The obtained values of root-mean-square deviation and relative average deviation are all less than 16.17 × 10–4 and 1.58%, respectively. The modified Apelblat equation achieved the best correlating results in totally.