Nanostructural organization in carbon disulfide∕ionic liquid mixtures: molecular dynamics simulations and optical...

Area of Science:

• Physical Chemistry
• Materials Science
• Chemical Physics

Background:

• Room temperature ionic liquids (RTILs) exhibit unique nanostructural organization.
• Understanding solute behavior in RTILs is crucial for designing new materials and processes.

Purpose of the Study:

• To investigate the concentration-dependent nanostructural organization and subpicosecond intermolecular dynamics of carbon disulfide (CS(2)) in 1-pentyl-3-methylimidazolium bis{(trifluoromethane)sulfonyl}amide ([C(5)mim][NTf(2)]).

Main Methods:

• Molecular dynamics (MD) simulations were employed to model the mixtures.
• Optical heterodyne-detected Raman-induced Kerr effect (OKE) spectroscopy was used to probe intermolecular dynamics.

Main Results:

• MD simulations revealed CS(2) localization in nonpolar domains at low concentrations (<10 mol.%) and aggregation at higher concentrations (≥10 mol.%).
• OKE spectra analysis indicated that CS(2) primarily resides in nonpolar domains, even at high concentrations.
• The local CS(2) concentration was found to be higher than the bulk concentration.

Conclusions:

• The nanostructure of [C(5)mim][NTf(2)] influences the organization of CS(2) molecules.
• Subpicosecond dynamics of CS(2) in RTILs are comparable to those in nonpolar solvents.
• The findings provide insights into molecular interactions and dynamics within ionic liquid-solute systems.