Solubility, solvent effects and thermodynamic properties of N-Ethyl-p-toluenesulfonamide in twelve pure organic solvents

Abstract

Background

The investigation of the solubility of N-Ethyl-p-toluenesulfonamide (N-PTSA) in organic solvents is crucial for its separation and purification in industrial processes.

Methods

The main interaction sites and interaction forces between N-PTSA molecules were identified through surface electrostatic, Hirshfeld surface, and 2D fingerprints analysis. And, the impact of solvent type on solubility was forecasted. Then, we utilized a traditional gravimetric method to determine the solubility of N-PTSA within a group of twelve pure solvents. These solvents included alcohols, esters, as well as ketones. The temperature ranging from 278.15 K to 323.15 K.

Significant Findings

The solubility of N-PTSA increases consistently with rising temperature across all solvents. Additionally, the solubility data was correlated using the modified Apelblat model, λh model, van't Hoff model, and NRTL model. The average values of average relative deviation are all below 5 %, indicates that all four selected models demonstrate accurate fits on the solubility data. In addition, the solute-solvent interaction results obtained from activity coefficient calculation further explain the reasons for the solubility differences of N-PTSA in different types of solvents. Finally, the positive apparent thermodynamic parameters values of Δ_solH⁰, Δ_solG⁰, and Δ_solS⁰ reveals that the dissolution of N-PTSA in all the neat solvents is an endothermic, non-spontaneous and entropy-driven process.