Solubility, solvent effect, preferential solvation and DFT computations of 5-nitrosalicylic acid in several aqueous blends. (February 2023) - Guo, Qirui
Graphical abstract: Highlights: Quantitative surface and HS analysis of 5-nitrosalicylic acid molecule was studied. Solubility of 5-nitrosalicylic acid in four aqueous blends were experimentally determined and correlated. Analysis of solubility data using KAT-LSER and extended Hildebrand solubility approach. Investigation on preferential solvation was made via IKBI method. Inter-molecular interactions in solution systems was investigated by IGMH. Abstract: The purpose of this contribution was to investigate the solubility, computational techniques, solvent effect, and preferential solvation of 5-nitrosalicylic acid in blended solvents of acetonitrile/ N, N -dimethylformamide(DMF)/methanol/ n -propanol + water. Visualizing regions of weak contact between 5-nitrosalicylic acid and solvent using an independent gradient model based on Hirshfeld partitioning (IGMH), and providing a quantitative study for the molecule's electrostatic characteristics using a molecular surface research and Hirshfeld surface analysis were carried out. All equilibrium solubility measurements were performed using a shake-flask technique at temperatures from 278.15 to 323.15 K and pressure of 101.2 kPa. For each blends studied, the lowest solubility was observed at 278.15 K in water and the highest at 323.15 K in pure organic solvent. Using linear solvation energy relationships, the effect of molecular interactions on solubility variation was studied, revealing that the solubility parameter and dipolarity-polarizability played a substantial impact in solubility variation. By correlating the derived equilibrium solubilities with the Jouyban-Acree, modified Apelblat-Jouyban-Acree, and van't Hoff–Jouyban–Acree models, a maximum relative average deviation of 4.01 percent was obtained. Quantitative investigation of the solvation behavior of 5-nitrosalicylic acid by solvent species was conducted using the method of inverse Kirkwood–Buff integrals. Positive values of the preferential solvation parameter in acetonitrile/DMF/methanol/ n -propanol-middle and -rich blended systems indicated that acetonitrile/DMF/methanol/ n -propanol solvated 5-nitrosalicylic acid preferentially. In the above composition ranges, it is hypothesized that 5-nitrosalicylic acid interacts with nearby methanol/DMF/ n -propanol molecules as a Lewis acid, whereas solvation by acetonitrile is due to the polarization effect.