Evaluation of Molecular Behavior of Priority of Water Pollutants with Ionic Liquids: COSMO Based Approach

Evaluation of chemical reactivity and polarity of imidazolium-based ionic liquids using quantum chemical calculations

CONTEXT

By using the DFT theory, the orbital energies of twenty-five ionic liquids were estimated. To comprehend their molecular stability and chemical reactivity, the orbital energy values, orbital energy gap (HOMO-LUMO energy gap), chemical hardness (η), chemical softness (S), electronegativity (χ), and electrophilicity index (ω) were computed. The interaction energies between all of the cations and anions under study were then computed and examined. Finally, using quantum chemical calculations, the molecular polarity of all 25 ionic liquids was examined using the sigma profile and sigma potential.

METHODS

Using the lowest orbital energy of the molecules, HF/6-31G* level of theory quantum chemical calculation were carried out using the MOLDEN and GAUSSIAN03 software. The B3LYP DFT approach produced a COSMO file that contained the species optimal SCD.

Investigation of Potential Azeotrope Breakers Using DFT and COSMO Approach

Different combinations of cations (imidazolium, pyridinium, pyrrolidinium, phosphonium, and ammonium) and anions (basic anions, sulfate, phosphate, and borate) were studied based on the COSMO volume and quantum chemical parameters such as highest occupied molecular orbital/lowest unoccupied molecular orbital (HOMO/LUMO) energies, HOMO-LUMO energy gap, global hardness and softness, electronegativity, electrophilicity index, and chemical potential using the density functional theory (DFT) method. Further, the sigma profile and sigma potential for the selected cations and anions were generated using a COSMO-RS model. The activity coefficient at infinite dilution was also studied for the butanol-water system to find a greater degree of nonideality. A feasible entrainer for the azeotrope breaker for a butanol-water system is proposed.