Electrostatic Manifestation of Micro-Heterogeneous Solvation Structures in Deep-Eutectic Solvents: A Spectroscopic Approach
| Autor: | Sayan Bagchi, Tapas Haldar, Deborin Ghosh, Srijan Chatterjee |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
Materials science
010304 chemical physics Spectrum Analysis Static Electricity Solvation Hydrogen Bonding 010402 general chemistry 01 natural sciences Choline 0104 chemical sciences Surfaces Coatings and Films Chemical physics 0103 physical sciences Solvents Materials Chemistry Physical and Theoretical Chemistry Eutectic system |
| Zdroj: | The Journal of Physical Chemistry B. 124:3709-3715 |
| ISSN: | 1520-5207 1520-6106 |
| DOI: | 10.1021/acs.jpcb.9b11352 |
| Popis: | Deep eutectic solvents have emerged as inexpensive green alternatives to conventional solvents for diverse applications in chemistry and biology. Despite their importance as useful media in various applications, little is known about the microscopic solvation structures of deep eutectic solvents around solutes. Herein, we show that the electrostatic field, which can be estimated both from infrared experiments and theory, can act as a unified concept to report on the microscopic heterogeneous solvation of deep eutectic solvents. Using a fluorophore containing the carbonyl moiety as the solute and the electrostatic field as a descriptor of the solvation structure of the deep eutectic solvents, we report the residue-specific distribution, orientation, and hydrogen bonding in deep eutectic solvents constituting of choline chloride and alcohols of varying chain-lengths. We observe that an increase in alcohol chain-length not only affects the alcohol's propensity to form hydrogen bond to the solute but also alters the spatial arrangement of choline cations around the solute, thereby leading to a microheterogeneity in the solvation structure. Moreover, to extend our electrostatic field based strategy to other deep eutectic solvents, we report an emission spectroscopy based method. We show that this method can be applied, in general, to all deep eutectic solvents, irrespective of their constituents. Overall, this work integrates experiments with molecular dynamics simulations to provide insights into the heterogeneous DES solvation. |
| Databáze: | OpenAIRE |
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