Solubility, solvent effect, correlation and thermodynamic properties of 3-methyl-1,2-cyclopentanedione in twelve pure organic solvents from 278.15 K to 313.15 K

Solubility data and regularity of 3-methyl-1,2-cyclopentanedione (MCP) in twelve pure organic solvents were investigated by static method under certain conditions. The results of experiments demonstrate that the solubility of MCP is proportional to the temperature. One of the most solubilizing solvents is dichloromethane. A preliminary assessment of the potential for chemical bond formation between the solute and the solvent was conducted by examining electrostatic potential energy surfaces of the solute. The dissolution behavior was explained by physicochemical properties (polarity, hydrogen bond donor–acceptor propensities and cohesive energy density (CED)) of solvent. The results demonstrate that polarity has a more pronounced impact on the dissolution process, but that other properties also effect the dissolution process to some extent. The Density Functional Theory (DFT) was applied to demonstrate interactions between solute and solvent during the dissolution process. Six thermodynamic models (van’t Hoff, Apelblat, Yaws, λh , Wilson, Jouyban) were utilized to fit solubility data. Wilson model exhibits the highest correlation. The thermodynamic properties indicate that the dissolution of the MCP can be described as an entropy-driven process, which is endothermic and spontaneous.