Determination of Solubility and Thermodynamic Analysis of Iron(III) β-Diketonate Compounds in Pure Solvents

In this work, the solubility of Fe(acac)₃ (acac = acetylacetone) in five organic solvents (n-propanol, diethyl ether, ethyl acetate, tetrahydrofuran, ethanol), Fe(acch)₃ (acch = 2-acetylcyclohexanoate) in five organic solvents (acetonitrile, diethyl ether, ethyl acetate, methyl acetate, ethanol) and Fe(ba)₃ (ba = benzoylacetone) in four organic solvents (acetonitrile, diethyl ether, ethyl acetate, methyl acetate) were determined from 268.15 to 298.15 K by static analysis. The measured results demonstrated that the solubility data increased with increasing temperature. Solubility for the complexes was related using five thermodynamic models. Among them, in terms of empirical models, the Apelblat model was broadly applicable and had an average ARD of less than 3%. The activity coefficient model (NRTL model) had a good fit effect with an average ARD of less than 1.5%. Furthermore, the molecular electrostatic potential (ESP) of iron(III) β-diketonate compounds reflected that O atoms readily formed hydrogen bonds. Hirshfeld surface analysis revealed that the largest contact rate was in the H···H contact.