Theoretical study on the interactions between methanol and imidazolium-based ionic liquids.

Area of Science:

• Physical Chemistry
• Computational Chemistry

Background:

• Ionic liquids (ILs) are versatile solvents with tunable properties.
• Methanol is a common alcohol used in various chemical processes.
• The miscibility of ILs with alcohols is crucial for their application as solvents.

Purpose of the Study:

• To investigate the interactions between methanol and imidazolium-based ILs.
• To elucidate the role of hydrogen bonds in the miscibility of these binary systems.
• To provide insights for designing improved ILs for alcohol mixtures.

Main Methods:

• Density functional theory (DFT) calculations were employed.
• Interactions between methanol, IL anions (Cl-, Br-, BF4-, PF6-), and the 1-ethyl-3-methylimidazolium ([emim]+) cation were analyzed.

Main Results:

• Hydrogen bonds are universally involved in the interactions between methanol and imidazolium-based ILs.
• Methanol-anion interactions primarily involve LP(X)-π interactions.
• Methanol-cation interactions are characterized by LP(O)-π orbital overlap.

Conclusions:

• Hydrogen bonding significantly influences the miscibility of methanol with imidazolium-based ILs.
• Distinct interaction mechanisms exist between methanol and IL anions versus cations.
• The findings offer valuable information for developing efficient ILs as superior solvent systems with alcohols.