Solid-Liquid Equilibrium and Thermodynamic Analysis of Transition Metal Complexes Supported by Bis(imino)pyridine in Different Solvents

In this work, a static analysis method was used to measure the solubility data of L₁ (1) (L₁ = 2, 6-bis{1-[(2-isopropylphenyl)imino]ethyl}pyridine) in five pure solvents, and L₁Zn (2) (L₁Zn = [2, 6-bis{1-[(2-isopropylphenyl)imino]ethyl}pyridine]ZnCl₂) and L₁Mn (3) (L₁Mn = [2, 6-bis{1-[(2-isopropylphenyl)imino]ethyl}pyridine]MnCl₂) in four pure solvents. Based on the results of the experiment, it was concluded that the solubility of the three complexes also increased as the temperature increased. Eight thermodynamic models were used to correlate experimental solubility data. The results yielded a good fit with an average absolute relative deviation (ARD) of less than 3.5% and an average root mean square deviation (RMSD) of less than 0.15% for these models. In addition, the range of molecular electrostatic potentials of the three compounds was obtained by molecular electrostatic potential analysis. Reasons for solubility differences were analyzed by calculating the Hansen solubility parameters of L₁. The solubility data measured in this paper can provide a theoretical basis and reference standard for the selection of reaction and recrystallization solvents in future experiments.