Solubility and Solution Thermodynamics of 2,6-Dichloro-4-nitroaniline in 12 Pure Solvents at Temperatures from 278.15 to 323.15 K

Abstract

The solubility of 2,6-dichloro-4-nitroaniline (DCNA) in 12 pure solvents of n-butanol, n-propanol, methanol, ethylene glycol (EG), ethanol, isopropanol, acetonitrile, cyclohexane, 1,4-dioxane, ethyl acetate, water, and N-methyl pyrrolidone (NMP) was achieved through the shake-flask method at the temperatures from 278.15 to 323.15 K and ambient pressure p = 101.2 kPa. The mole fraction solubility of DCNA in the above solvents increased as the temperature increased and ranked as NMP > 1,4-dioxane > ethyl acetate > acetonitrile > n-butanol > n-propanol > ethanol > EG > isopropanol > methanol > cyclohexane > water. The solvent–solvent and solvent–solute interactions on the DCNA solubility were investigated using the linear solvation energy relationship on the basis of the solvent descriptors. The acquired solubility was correlated using the NRTL model, λh equation, modified Apelblat equation, and Wilson model. The obtained maximum relative average deviation and root-mean-square deviation were 6.53 × 10–2 and 13.73 × 10–4, respectively. In general, the relative average deviation values achieved through the modified Apelblat equation were lower than those with the other three equations for a certain solvent. In addition, the mixing properties, reduced excess enthalpy, and activity coefficient under infinitesimal concentration were derived based on the Wilson model.