Solubility Determination, Solvent Effect, Thermodynamic Modeling, and Preferential Solvation of 2-Cyanoacetamide in Four Aqueous Binary Mixtures of Alcohols

Abstract

The solubility of 2-cyanoacetamide (2-CA) was ascertained by means of a gravimetric technique in four different kinds of aqueous mixed solvents, specifically water + (methanol (MeOH), ethanol (EtOH), 1-propanol (1-PrOH), or 2-propanol (2-PrOH)). The experiment was conducted between 283.15 and 323.15 K in temperature. The findings show that in all four binary solvent systems, 2-CA becomes more soluble at higher temperatures. The KAT-LSER model was employed to analyze the impact of solute–solvent intermolecular interactions on solubility. In order to simulate the solubility of 2-CA in binary mixed solvents, three thermodynamic models were used. The low values for the average relative deviation (RAD%) (≤1.23, ≤2.20, and ≤3.68) show that the experimental solubility data for 2-CA in the four binary solvent mixtures exhibit strong agreement with the correlated data utilizing the Jouyban–Acree, Jouyban–Acree–van’t Hoff, and Apelblat–Jouyban–Acree models. The thermodynamic properties of the solution were used to calculate the special solvation variables by the use of inverse Kirkwood–Buff integrals. The preferential solvation variables for MeOH/EtOH/1-PrOH/2-PrOH displayed negative values in the MeOH (1) + water (2) mixture, within the range of 0.31 < x₁ < 1, for the EtOH (1) + water (2) mixture with compositions falling between 0.24 < x₁ < 1, for the 1-PrOH (1) + water (2) mixture with compositions within 0.20 < x₁ < 1, and for the 2-PrOH (1) + water (2) mixture within the range of 0.20 < x₁ < 1. This suggests that while alcohol preferentially solvates water molecules in surroundings rich in alcohol, alcohol molecules preferentially solvate 2-CA in mixes rich in water.