CHEMICAL PHYSICS LETTERS
·
2024
·
IF 2.8
Ting-ting Yan,Yi-fei Xu,Dong-yang Xi,Zhiqing Yu,Long Ma,Dan-dan Zhang,Ran Jiang
The study investigated the behavior of N-nitropyrazole (1-NP, C 3 H 3 N 3 O 2 ) under high pressure using a diamond anvil cell, Raman spectroscopy, and simulation calculations. The pressure–volume relationship of the sample, molecular interactions, and changes in optical Raman were analyzed. The Raman experiments revealed abnormal vibration intensities and a discontinuity in peak position at 2.2 GPa. For instance, the C-H stretching vibration produces a new vibration peak under pressure, and the NO 2 torsion mode continues to red shift beyond 2.2 GPa. These observations suggest that the crystal’s phase transition results from the distortion of its hydrogen-bonded network structure. The pressure relief experiment confirms the reversibility of the phase transition.
研究领域:
化学
·
材料科学
✓ 已验证
DOI
高影响因子
JOURNAL OF CHEMICAL AND ENGINEERING DATA
·
2023
·
IF 2.6
Fanfan Shen,Xinqiang Pang,Yongzheng Liu,Linxiu Zhao,Fang Chen,Yongxiang Li,Duanlin Cao
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 (R2), the Wilson equation yielded a more satisfactory correlation result. Thermodynamic parameters of mixing enthalpy (ΔmixH), mixing entropy (ΔmixS), and mixing Gibbs energy (ΔmixG) were calculated and analyzed based on the experimental data. The positive ΔmixH and ΔmixS 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.
研究领域:
化学工程
·
物理化学
✓ 已验证
DOI
高影响因子
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