Probing the influence of Zn and water on solvation and dynamics in ethaline and reline deep eutectic solvents by ¹H nuclear magnetic resonance

Abstract

A range of ethaline and reline deep eutectic solvents (DESs) have been investigated in the absence and presence of Zn (0 - 0.3 M) and water (0 - 29 wt.%)...

Insight into the Molecular Structure, Interaction, and Dynamics of Aqueous Reline Deep Eutectic Solvent: A Nuclear Magnetic Resonance Investigation

“…It is revealed that the correlation between −NH 2 and −OH should be originated from the proton exchange behavior. This is different from the idea as proposed by AlZahrani et al Details of the motion and chemical exchange study will be discussed in the section of MD investigation in this article.…”

“…According to 1 H spectrum, all the signals present a broad line shape. This is ascribed to the high viscosity of pure reline, which has been widely investigated in published works. ,, To further study the liquid structure of R-0, NOESY, COSY and ROESY experiments were conducted. As shown in Figure c, in NOESY spectrum, correlations between alkyl protons and −NH 2 protons were probed, especially for −CH 3 with more enhanced signal.…”

“…However, at a higher hydration level, it started to irrupt near the hydroxyl and ammonium groups of Ch + but at a closer distance than other Ch + owing to enhanced H-bonding interactions between the Ch + hydroxyl group and water molecules. Apart from MD simulations, several nuclear magnetic resonance (NMR) techniques have been employed to reveal the impact of water in reline. ,− AlZahrani et al observed that the presence of water led to a significant reduction of 1 H NMR linewidth, which correlated to the decrease of liquid viscosity . Based on NMR and Raman study, Di Pietro el al.…”

“…25,36−40 AlZahrani et al observed that the presence of water led to a significant reduction of 1 H NMR linewidth, which correlated to the decrease of liquid viscosity. 39 Based on NMR and Raman study, Di Pietro el al. pointed that in the presence of increasing water, reline maintained its structure as small interplays gradually occur between urea in the reline and the surrounding water molecules.…”

Controlled Solvation Structure of a Zn Ion in an Aqueous Electrolyte by Amine Additives for Long Cycle Life of a Large Capacity Zn-Air Rechargeable Battery

“…It is interesting that although the local environment of H + was the same, T1 relaxation time was increased by addition of amines, suggesting that OH − was more strongly solvated and H + is more mobile and so mobility of Zn 2+ may also be increased by addition of amines. 30,31 This increased T1 relaxation time also suggests that the solvated structure of Zn(OH) 2 is more polarized, and the electron density on solvated Zn 2+ is delocalized by the strong electronic interaction between the added amine and solvated H 2 O, and so, the coordination…”