Solubility and Preferential Solvation of 3-Nitrobenzonitrile in Binary Solvent Mixtures of Ethyl Acetate Plus (Methanol, Ethanol, n-Propanol, and Isopropyl Alcohol)

Abstract

The solubilities of 3-nitrobenzonitrile in solvent mixtures of ethyl acetate (1) + methanol (ethanol, n-propanol or isopropyl alcohol) (2) determined over the temperature range from 278.15 to 318.15 K under atmospheric pressure (101.1 kPa) with the isothermal dissolution equilibrium method were reported. They increased with a rise of temperature and mass fraction of ethyl acetate, and the largest solubility value was observed in neat ethyl acetate for all the binary mixtures investigated. The temperature and solvent composition dependence of 3-nitrobenzonitrile solubility was analyzed through the Jouyban−Acree, van't Hoff− Jouyban−Acree, and Apelblat−Jouyban−Acree models acquiring average relative deviations lower than 1.57% and root-mean-square deviation lower than 11.52 × 10 −4 for correlative investigations. In addition, the preferential solvation parameters (δx 1,3 ) of 3-nitrobenzonitrile by ethyl acetate were determined from experimental solubility values by using the inverse Kirkwood−Buff integrals. It was found that alcohol preferentially solvated 3-nitrobenzonitrile in alcohol-rich mixtures while ethyl acetate forms local solvation shells in compositions from intermediate composition up to neat ethyl acetate. The former case was possibly due to the ordered structure of alcohol molecules around the apolar group of 3-nitrobenzonitrile, which was formed via hydrophobic hydration in alcohol-rich solutions.

Solubility Determination and Modeling for 4-Nitrobenzonitrile in Binary Solvent Mixtures of Ethyl Acetate Plus (Methanol, Ethanol, n-Propanol, and Isopropanol)

“…Several models have been proposed and employed in correlating the solid solubility in solvent mixtures in literatures. ,, In this work, three models, Jouyban–Acree, ,, Apelblat–Jouyban–Acree , and van’t Hoff–Jouyban–Acree , are used in correlating the solubility of 4-nitrobenzonitrile in binary mixed solvents.…”

“…The Jouyban–Acree model described as eq has been widely used to describe the dependence of solute solubility on both temperature and solvent composition for mixed solvents ,, here x w,T denotes the 4-nitrobenzonitrile solubility in mole fraction in mixed solvents at temperature T /K; w 1 and w 2 refer to, respectively, the mass fraction of solvent 1 (ethyl acetate) and solvent 2 (ethanol, methanol, isopropanol, and n -propanol) in 4-nitrobenzonitrile-free mixtures; x 1,T and x 2,T stand for the 4-nitrobenzonitrile solubility in neat solvent 1 and solvent 2; and J i are the model parameters.…”

“…The apparatus shown in Figure is similar to that used in our published works. − This apparatus comprised a circulating water system, a stirrer, and a jacketed vessel. The water temperature was regulated through a water bath (QYHX-1030) produced by Shanghai Joyn Electronic Co., Ltd., China, in which standard uncertainty was 0.05 K. Between the inner and outer walls of the flask was circulating water.…”

“…The solubility determination of 4-nitrobenzonitrile in (ethanol + ethyl acetate), (methanol + ethyl acetate), (isopropanol + ethyl acetate), and ( n -propanol + ethyl acetate) mixtures were carried out through the isothermal equilibrium technique. − Saturated solutions of 4-nitrobenzonitrile were prepared in the flask through introducing excess 4-nitrobenzonitrile to the flask filled with about 60 mL mixed solutions. Then the solutions were stirred with about 200 rpm at the desired temperatures.…”

“…The knowledge concerning solubility in solvent mixtures can enable us to discover suitable solvents in purifying 4-nitrobenzonitrile. Recently, the solubility of 3-nitrobenzonitrile in some pure organic solvents and solvent mixtures determined with static method at several temperatures are reported. , So as to explore a novel purification procedure for nitrobenzonitrile isomers, the goals of the present paper are to determine the solubility of 4-nitrobenzonitrile in solvent mixtures of (ethanol + ethyl acetate), (methanol + ethyl acetate), (isopropanol + ethyl acetate), and ( n -propanol + ethyl acetate) and correlate the obtained solubility data with different models.…”