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Exploring Dynamics and Intermolecular Interactions in Binary Mixtures of Reline and DMSO: An Investigation Using
Huan Chen1, Bona Dai2, Lingyun Xu3,4
1College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123, China.
The Journal of Physical Chemistry. B
|January 17, 2025
Summary
Dimethyl sulfoxide (DMSO) addition to reline (choline chloride and urea deep eutectic solvent) causes a transition at 0.7 molar fraction. This shift enhances molecular mobility and alters hydrogen bonding, impacting mixture properties.
Area of Science:
- Physical Chemistry
- Materials Science
Background:
- Reline, a choline chloride and urea deep eutectic solvent (DES), is widely studied.
- Blending reline with dimethyl sulfoxide (DMSO) can improve its properties.
- Understanding DMSO's effect on reline mixtures is crucial for applications.
Purpose of the Study:
- To investigate the structural and dynamic changes in reline/DMSO mixtures.
- To determine the impact of varying DMSO concentrations on reline's properties.
- To elucidate the role of hydrogen bonding in these mixtures.
Main Methods:
- Utilized nuclear magnetic resonance (NMR) spectroscopy (1D 1H, 15N, 2D 1H-1H COSY).
- Employed Fourier transform infrared (FT-IR) spectroscopy.
- Analyzed self-diffusion coefficients and relaxation times (1H T1, T2).
Main Results:
- A significant transition observed in reline/DMSO mixtures at a DMSO molar fraction of 0.7.
- Increased molecular mobility and enhanced diffusion noted above 0.7 DMSO fraction.
- Disruption of hydrogen bonds involving -NH2 and -OH groups correlated with increased mobility.
- Urea-choline interaction weakens above 0.7 DMSO fraction, with DMSO forming hydrogen bonds.
Conclusions:
- DMSO induces a transition in reline mixtures around 0.7 molar fraction, shifting from viscous liquids to nonviscous solutions.
- This transition is characterized by enhanced molecular mobility and altered hydrogen bonding dynamics.
- Findings provide insights into reline/DMSO mixture behavior, consistent with simulation studies.
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