Solubility of the Schiff Base Ligand and the Organoaluminum Supported by the Ligand in Pure Solvents: Characterization, Determination, Analysis, and Model Correlation

Abstract

Schiff bases and organoaluminum compounds have wide applications in medicine and catalysis. TG-DSC provided melting points and melting enthalpies for the Schiff base ligand (1, 2-[[(2,6-difluorophenyl)­imino]­methyl]­phenol, CAS: 26672-04-8), with T m at 349.55 K and ΔH fus at 22.797 kJ/mol, and for the organoaluminum compound supported by the ligand (2, [2-[[(2,6-difluorophenyl)­imino]­methyl]­phenoxy]­dimethylaluminum, CAS: 2851050-89-8), with T m at 396.04 K and ΔH fus at 11.137 kJ/mol. The range of molecular electrostatic potentials for the two compounds was obtained by molecular electrostatic potential analysis, with the potential range for compound 1 being from +95.1 kJ/mol to −133.2 kJ/mol and that for compound 2 being from +139.9 kJ/mol to −132.7 kJ/mol. Hirshfeld surface analysis indicated that H···H contacts were the dominant contact interactions in these two molecules. In addition, the solubilities of the two compounds in 11 pure solvents were determined, and experimental data were correlated using 7 thermodynamic equations. The results displayed that the NRTL model had the best correlation result for the two compounds. These experimental results will have significant implications for the purification, crystallization, and industrial applications of similar types of substances.

Determination of Solubility and Thermodynamic Analysis of Iron(III) β-Diketonate Compounds in Pure Solvents

“…The Hirshfeld surface analysis of Fe­(acac) 3 (1) and Fe­(ba) 3 (3) were shown in Figures and . The red spots represented the locations where hydrogen bonding may occur, the blue area indicated that the contact distances between the corresponding atoms exceeded the van der Waals force, and the white areas represented the contact distances comparable to van der Waals forces . Consistent with the results of the ESP, red spots were observed in Fe­(acac) 3 and Fe­(ba) 3 around the O atoms, suggesting that these regions were more prone to hydrogen bonding.…”

Solid–Liquid Equilibrium and Thermodynamic Analysis of Transition Metal Complexes Supported by Bis(imino)pyridine in Different Solvents

“…The MEPS (molecular electrostatic potential surface) was used to analyze the overall distribution of intermolecular charges and intermolecular interactions. The molecular structures of the three compounds were optimized using density functional theory in Gaussian 09 software based on B3LYP/6–311+G (d, p), and the results were analyzed using Multiwfn software. , …”

“…The molecular structures of the three compounds were optimized using density functional theory in Gaussian 09 software based on B3LYP/6−311+G (d, p), and the results were analyzed using Multiwfn software. 13,14 2.3. Synthesis and Characterization.…”

“…Comparing the MESP of the three compounds, it is found that the Zn atom in compound 2 and the Mn atom in compound 3 are electronegative, resulting in electronegativity near the metal center and an increase in the electropositivity of the ligand framework. 13 As can be seen from the figure, the structure of the ligand is slightly distorted, which may be due to the electrical effect and coordination of the ligand on the metal atom; it also affects the surface electrostatic potential of the molecular structure. Due to the hydrogen bond receptors, the three compounds can hydrogen bond with a variety of solvents, thus promoting the solute to dissolve.…”