Thermodynamic Functions for Solubility of 1‑Hydroxybenzotriazole in Sixteen Solvents at Temperatures from (278.15 to 313.15) K and Mixing Property of Mixtures

Solubility of 1-hydroxybenzotriazole in 16 neat solvents including methanol, ethanol, <i>n</i>-propanol, isopropanol, acetone, butanone, isoamyl alcohol, <i>n</i>-hexanol, <i>n</i>-heptanol, isooctyl alcohol, <i>N</i>,<i>N</i>-dimethylformamide (DMF), dimethyl sulfoxide (DMSO), ethyl acetate, acetonitrile, 1,4-dioxane, and toluene was measured using the method of isothermal saturation over a temperature range from (278.15 to 313.15) K under atmospheric pressure (101.1 kPa). The mole fraction solubility of 1-hydroxybenzotriazole in the selected solvents increased with an increase of temperature. They followed the order from high to low in studied neat solvents: DMF > DMSO > ethanol > <i>n</i>-propanol > isopropanol > methanol > butanone > acetone >1,4-dioxane > <i>n</i>-heptanol > <i>n</i>-hexanol > isoamyl alcohol > isooctyl alcohol > ethyl acetate > acetonitrile > toluene. The obtained solubility data of 1-hydroxybenzotriazole in the studied solvents were correlated with the <i>λh</i> equation, modified Apelblat equation, and NRTL and Wilson models. The largest value of root-mean-square deviation was 7.65 × 10^–4, and relative average deviation, 4.21%. The values of root-mean-square deviation obtained with the modified Apelblat equation were smaller than those with the other equations for a given solvent. By and large, the four thermodynamic models all provided acceptable results for 1-hydroxybenzotriazole in the studied solvents. Moreover, the apparent dissolution enthalpy and the mixing enthalpy, mixing Gibbs energy, mixing entropy, reduced excess enthalpy, and activity coefficient at infinitesimal concentration were derived. The obtained solubility and thermodynamic studies could provide the fundamental data for optimizing the reaction and purification procedure of 1-hydroxybenzotriazole

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

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 <i>N</i>,<i>N</i>-dimethylformamide. They were determined by a high-performance liquid chromatography at <i>T</i> = (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 <i>N</i>,<i>N</i>-dimethylformamide and lowest in chloroform. The solubility data in the these solvents ranked as <i>N</i>,<i>N</i>-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, <i>λh</i> 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