TY - JOUR
T1 - Solubility and thermodynamic modeling of Schiff-base ligands and their vanadium oxo complexes in organic solvents
AU - Han, Chunling
AU - Ma, Xiaoli
AU - Yang, Xiaobo
AU - Pang, Ziyuan
AU - Yang, Zhi
N1 - Publisher Copyright:
© 2026 The Authors
PY - 2026/6
Y1 - 2026/6
N2 - The solubilities of two Schiff-base ligands H2L1 and H2L2 (L1=N,N′-bis(3,5-di-tert-butylsalicylidene)-1,2-diphenylethane-1,2-diamine;L2=N,N′-bis(3,5-di-tert-butylsalicylidene)propane-1,2-diamine) and their corresponding oxovanadium(IV) complexes (VOL1 and VOL2) were systematically determined in selected organic solvents using the static equilibrium method over the temperature range of 278.15 - 313.15 K. Solid-liquid equilibrium data were correlated using several empirical equations (Apelblat, van't Hoff, Yaws, polynomial, and λh) as well as activity-coefficient models (Wilson, NRTL, and UNIQUAC). All systems exhibited a monotonic increase in solubility with temperature, indicating endothermic dissolution behavior. Among the investigated models, UNIQUAC provided the most accurate correlation for H2L1, NRTL showed superior performance for H2L2, while the polynomial empirical model yielded the best overall fit for both vanadium complexes. Thermodynamic analysis revealed that the dissolution processes are predominantly enthalpy-driven. Furthermore, Hansen solubility parameters were employed to rationalize solvent-solute interactions and explain solvent-dependent solubility trends. The experimental data and thermodynamic modeling presented in this work provide a reliable basis for solvent screening, solubility prediction, and process-relevant applications of Schiff base vanadium complexes in homogeneous systems. The present data thus provide quantitative guidance for solvent selection and operating condition design in homogeneous catalytic processes and other solution-phase applications.
AB - The solubilities of two Schiff-base ligands H2L1 and H2L2 (L1=N,N′-bis(3,5-di-tert-butylsalicylidene)-1,2-diphenylethane-1,2-diamine;L2=N,N′-bis(3,5-di-tert-butylsalicylidene)propane-1,2-diamine) and their corresponding oxovanadium(IV) complexes (VOL1 and VOL2) were systematically determined in selected organic solvents using the static equilibrium method over the temperature range of 278.15 - 313.15 K. Solid-liquid equilibrium data were correlated using several empirical equations (Apelblat, van't Hoff, Yaws, polynomial, and λh) as well as activity-coefficient models (Wilson, NRTL, and UNIQUAC). All systems exhibited a monotonic increase in solubility with temperature, indicating endothermic dissolution behavior. Among the investigated models, UNIQUAC provided the most accurate correlation for H2L1, NRTL showed superior performance for H2L2, while the polynomial empirical model yielded the best overall fit for both vanadium complexes. Thermodynamic analysis revealed that the dissolution processes are predominantly enthalpy-driven. Furthermore, Hansen solubility parameters were employed to rationalize solvent-solute interactions and explain solvent-dependent solubility trends. The experimental data and thermodynamic modeling presented in this work provide a reliable basis for solvent screening, solubility prediction, and process-relevant applications of Schiff base vanadium complexes in homogeneous systems. The present data thus provide quantitative guidance for solvent selection and operating condition design in homogeneous catalytic processes and other solution-phase applications.
KW - Activity coefficient models
KW - Hansen solubility parameters
KW - Schiff base vanadium complexes
KW - Solid-liquid equilibrium
KW - Solvent screening
KW - Thermodynamic modeling
UR - https://www.scopus.com/pages/publications/105038883360
U2 - 10.1016/j.ctta.2026.100322
DO - 10.1016/j.ctta.2026.100322
M3 - Article
AN - SCOPUS:105038883360
SN - 2667-3126
VL - 22
JO - Chemical Thermodynamics and Thermal Analysis
JF - Chemical Thermodynamics and Thermal Analysis
M1 - 100322
ER -