Thermodynamic functions of 1-methyl-4-(methylsulfonyl)benzene solubility in nine organic solvents from T = (278.15 to 318.15) K

Abstract

The solid-liquid equilibrium for 1-methyl-4-(methylsulfonyl)benzene in nine solvents (methanol, ethanol, acetonitrile, ethyl acetate, acetone, N,N-dimethylformamide, n-butanol, n-propanol, isopropanol) were determined at temperatures from 278.15K to 318.15K by using the isothermal saturation method under atmosphere pressure, and the solubility of 1-methyl-4-(methylsulfonyl)benzene in the solvents were analysed by the high-performance liquid chromatography (HPLC). On the whole, the solubility obeyed the following order from high to low for the selected solvents: N,N-dimethylformamide>acetone>acetonitrile>ethyl acetate>methanol>ethanol>n-propanol>n-butanol>isopropanol. The four thermodynamic models, modified Apelblat equation, λh equation, Wilson model and NRTL model were used to describe the solubility results obtained. The largest values of relative average deviation (RAD) and root-mean-square deviations (RMSD) were 1.48% and 56.85×10−4, respectively. The calculated solubility with the four models agreed well with the experimental values. Furthermore, the mixing properties, including mixing Gibbs energy, mixing enthalpy, mixing entropy, activity coefficient at infinitesimal concentration (γ1∞) and reduced excess enthalpy (H1E,∞) were calculated for the dissolution process of 1-methyl-4-(methylsulfonyl)benzene in these solvents. The mixing process of 1-methyl-4-(methylsulfonyl)benzene was spontaneous and favourable in the selected solvents. The solubility of 1-methyl-4-(methylsulfonyl)benzene in different solvents and thermodynamic relations would be invoked as basic data and models for the purification process of 1-methyl-4-(methylsulfonyl)benzene.