Solubility and Preferential Solvation of Carbazochrome in Solvent Mixtures of <i>N</i>,<i>N</i>‑Dimethylformamide Plus Methanol/Ethanol/<i>n</i>‑Propanol and Dimethyl Sulfoxide Plus Water

Abstract

The carbazochrome (3) solubility in solvent mixtures of DMF (<i>N</i>,<i>N</i>-dimethylformamide, 1) + methanol (2), DMF (1) + ethanol (2), DMF (1) + <i>n</i>-propanol (2), and dimethyl sulfoxide (DMSO, 1) + water (2) was measured by the static method within the temperature range from (278.15 to 318.15) K under atmospheric pressure, <i>p</i> = 101.0 kPa. The solubility of carbazochrome increased with rising mass fraction of DMF or DMSO and temperature. The Jouyban–Acree, van’t Hoff–Jouyban–Acree, and Apelblat–Jouyban–Acree models were used to correlate the obtained solubility, and the Apelblat–Jouyban–Acree model provided better correlation results. The parameters of preferential solvation (<i>δx</i>_1,3) were acquired from the mixture properties with the method of inverse Kirkwood–Buff integrals. The values of <i>δx</i>_1,3 changed nonlinearly with the DMF/DMSO (1) proportion in the studied mixed solvents. The carbazochrome was solvated preferentially by alcohol or water in alcohol or water-rich solutions and preferentially solvated by DMF/DMSO in DMF/DMSO-rich mixtures. It could be speculated that in DMF/DMSO-rich mixtures the interaction by acidic hydrogen bonding with the basic sites of carbazochrome played a significant role in carbazochrome solvation