Solubility, thermodynamic properties, HSP, and molecular interactions of vitamin K3 in pure solvents

Due to the lack of solubility data and thermodynamic parameters of vitamin K3 in literature, we determined the solubility of vitamin K3 in ten organic solvents including 1,2-dichloroethane, acetone, dichloromethane, cyclohexane, methanol, acetonitrile, methyl acetate, i-propanol, n-propanol and n-butanol in this research. It was found that the solubility of vitamin K3 increases with the increasing temperature ranging from 278.15 to 313.15 K in all ten solvents. Four thermodynamic models regression illustrate that modified Apelblat is the most appropriate model to describe solubility of vitamin K3 in these ten solvents; it provides 100RAD value of 1.48 as well as 104RMSD value of 5.94. To explain the change patterns of vitamin K3 solubility in ten solvents, Hansen solubility parameters and DFT calculation were both applied. Outcomes indicate the solubility laws of vitamin K3 not only depend on polarity and hydrogen bonded parameters but also rely on intermolecular interactions. On account of these, 1,2-dichloroethane and dichloromethane with stronger solute-solvent interactions show greater solubility than other solvents. Thermodynamic studies reveal that the dissolution of vitamin K3 in these ten solvents is an entropy-driven and endothermic process.