Dissolution behavior, thermodynamic and kinetic analysis of malonamide by experimental measurement and molecular simulation

Abstract

In this study, the solid structure, dissolution behavior, thermodynamic properties and nucleation kinetics of malonamide were explored. Firstly, the Hirshfeld surface analysis and molecular electrostatic potential surface were plotted to reveal the percentage contribution of various intermolecular contacts and location of the strongest hydrogen bond. Next, the solubility of malonamide in 12 solvents was determined by dynamic method at temperatures from 278.15 K to 318.15 K. Four thermodynamic models were applied to analyze solubility results. In addition, the thermodynamic properties were calculated to further analyze and discuss the dissolution behavior of malonamide. Moreover, the physicochemical properties of solvents were explored to express the solvent effects. The results illustrate “like dissolves like”, “mass transfer” and “solvent-solute interaction” rules play the synergistic effects on the dissolution process. The molecular dynamic simulation, including radial distribution function analysis and solvent free energy, was used to further explain the dissolution behavior. At last, the nucleation rate and effective interfacial energy in methanol solvent was measured and calculated to reveal the nucleation behavior.