Composition dependent structural organization in trihexyl(tetradecyl)phosphonium chloride ionic liquid-methanol...

Area of Science:

• Physical Chemistry
• Materials Science
• Computational Chemistry

Background:

• Ionic liquids (ILs) and methanol mixtures are crucial in various chemical processes.
• Understanding their structural organization is key to optimizing applications.
• Molecular dynamics simulations offer insights into complex liquid mixtures.

Purpose of the Study:

• To investigate the structural arrangement of ions and molecules in [P666,14 (+)][Cl(-)] and methanol mixtures.
• To analyze the effect of composition on charge and polarity ordering.
• To elucidate the solvation behavior within the mixture.

Main Methods:

• Molecular dynamics (MD) simulations were employed.
• X-ray scattering structure function, S(q), was computed.
• A partitioning scheme was utilized for multi-component mixture analysis.
• Radial distribution functions (RDFs) were calculated.

Main Results:

• The total S(q) exhibited two peaks, indicating distinct correlations.
• Methanol structure dominated at low IL concentrations (xIL ≤ 0.1).
• A transition from methanol-like to IL-like structures occurred between 0.1 < xIL ≤ 0.7.
• IL-like structures were recovered at high IL concentrations (xIL > 0.7).
• Anions preferentially solvated methanol's hydroxyl group and IL cations.

Conclusions:

• The composition significantly influences the structural organization of IL-methanol mixtures.
• A transition in structural dominance from methanol to the ionic liquid is observed.
• Specific solvation preferences exist between ions and methanol molecules.