The Journal of Physical Chemistry B, Journal Year: 2025, Volume and Issue: unknown
Published: April 9, 2025
In this study, we investigated the intermolecular dynamics, including vibration and orientational of five deep eutectic solvents (DESs) consisting lithium bis(trifluoromethylsulfonyl)amide organic amides, such as acetamide, propanamide, N-methylacetamide, butyramide, urea, at a mole ratio 1:3 using femtosecond Raman-induced Kerr effect spectroscopy (fs-RIKES) subpicosecond optical (ps-OKES). The fs-RIKES results showed that line shape low-frequency band N-methylacetamide was trapezoidal, while other amide-based DESs bimodal. peak first moment vibrational appearing in frequency range less than 250 cm-1 for acetamide- urea-based were higher-frequency region compared to three DESs, indicating stronger interactions. Furthermore, analysis intramolecular bands anion population transoid conformer slightly higher DES suggesting urea solvate cations more amides. slow relaxation dynamics all captured up 1 ns ps-OKES. also depended on amide species. However, time constant did not show clear correlation with viscosity; therefore, follow Stokes-Einstein-Debye hydrodynamic model. densities, viscosities, surface tensions, electrical conductivities measured comparison spectroscopic results.
Language: Английский