Solubility, Correlation, Dissolution Properties, and Molecular Simulations of an Explosive Intermediate in Twelve Pure Solvents

Abstract

The solubility and thermodynamic properties of N-nitropyrazole (N-NP) in different pure solvents are crucial for crystallization, purification, and further theoretical research. The solid–liquid equilibrium solubility of N-NP in the range of 293.15–323.15 K was determined in 12 pure solvents of water, mesitylene, n-hexane, cyclohexane, ethanol, chlorobenzene, benzonitrile, propylene glycol, anisole, dimethyl sulfoxide, N,N-dimethylformamide, and o-dichlorobenzene by the laser dynamic method at an atmospheric pressure of 0.1 MPa. In the temperature range of 293.15–323.15 K, the solubility of N-NP in water, mesitylene, n-hexane, cyclohexane, ethanol, chlorobenzene, benzonitrile, propylene glycol, anisole, dimethyl sulfoxide, N,N-dimethylformamide, and o-dichlorobenzene displayed the mole fraction solubility of 0.001271–0.003540, 0.033858–0.139782, 0.001966–0.009268, 0.002621–0.013898, 0.013601–0.058669, 0.097849–0.310726, 0.170722–0.387823, 0.017647–0.065427, 0.069507–0.379656, 0.225911–0.457260, 0.210072–0.415353, and 0.017651–0.172345, respectively. The measured solubility data of N-NP had a good correlation with the modified Apelblat equation, the NRTL equation, the Wilson equation, as well as the λh equation. Through the comparison of the minor average of the root-mean-square deviation (103RMSD) and the coefficient of determination (R 2), the Wilson equation yielded a more satisfactory correlation result. Thermodynamic parameters of mixing enthalpy (Δmix H), mixing entropy (Δmix S), and mixing Gibbs energy (Δmix G) were calculated and analyzed based on the experimental data. The positive Δmix H and Δmix S implied that the dissolution process of N-NP in the selected solvents was endothermic and entropy-driven. The relative contributions of enthalpy and entropy demonstrated that enthalpy was the main contributor to the Gibbs free energy in the dissolution process. In addition, the solute–solvent interaction was calculated to elaborate the solubility of N-NP in selected solvents deeply. In addition, the solid–liquid surface tension and the surface entropy factor of N-NP were discussed on the basis of the experimental solubility data.

Equilibrium Solubility of Domiphen Bromide in 12 Mono Solvents: Determination and Correlation

“…Solubility data of medicines in different solvents plays a pivotal role in selecting crystallization methods and realizing high-purity production. 1,2 As a result, it is necessary to gain phase equilibrium solubility data of domiphen bromide in organic solvents and choose a suitable separation method. Domiphen bromide (C 22 H 40 BrNO, molar mass 414.46 g• mol −1 ; CAS: 538-71-6) 3 is an aromatic quaternary ammonium salt that is a white powder.…”

“…Solid–liquid equilibrium properties play an important role in separation processes and the design of crystallization equipment in pharmaceutical chemistry. Solubility data of medicines in different solvents plays a pivotal role in selecting crystallization methods and realizing high-purity production. , As a result, it is necessary to gain phase equilibrium solubility data of domiphen bromide in organic solvents and choose a suitable separation method.…”