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[Display omitted] • The minimum water content for a stable MA:S:W NADES was in a molar ratio of 1:1:3. • The effect of water on the properties of NADESs was explored. • The nanostructure of NADESs was studied experimentally and theoretically. • Water bridges the other two components through hydrogen bonds. • Solvation effect of water facilitates the proton transfer. Natural deep eutectic solvents (NADESs) have drawn significant attention as green solvents for their special properties like biodegradability and biocompatibility. Nevertheless, the high viscosity of NADESs tends to prevent their implementation in industry. Even though dilution with water will lower the viscosity of NADESs effectively, fundamental knowledge of the intermolecular network in NADESs as well as the effect of water on the cooperative hydrogen-bonding network has not been evaluated systematically. Herein, solutions spanning a range of molar ratios of DL-Malic acid, L-Serine and water were synthesized. The experimental results demonstrate that it takes at least three moles of water to achieve a stable NADES. Besides, density functional theory (DFT) calculations indicate that water molecules connect DL-Malic acid and L-Serine by a water bridge framework. Furthermore, the progressive addition of water facilitates the proton transfer, making the hydrogen atom of the carboxyl group gradually ionize and approach the amino group. We hope the findings would provide a better understanding of the structural characteristics of NADESs and shed light on the applications. [ABSTRACT FROM AUTHOR]

• POM-based PILs with high specific surface area were successfully prepared with template-free strategy. • Deep oxidative desulfurization and recycling ability can be achieved without any extractant. • The structure–activity relationship was investigated through various technologies. • DFT calculations were employed to investigate the interaction nature between catalysts and sulfides. Interfacial properties of catalysts and distribution of active sites affect the catalytic oxidative desulfurization activity, which has become the research focus in recent years. Towards desulfurization in fuel, a kind of amphiphilic and polyoxometalate poly(ionic liquids) was prepared by the cross-linking copolymerization and ion exchange reaction. The resulting samples characterized in detail were employed in the oxidation of refractory aromatic sulfur-containing compounds. With H 2 O 2 as the oxidant, the sample p-C 2 VIM-DVB-2-PMo exhibited enhanced desulfurization performance and good thermal stability, meeting the demand of deep desulfurization. Besides, no significant decrease on sulfur removal was observed after recycling for 8 times. Moreover, density functional theory calculations were employed to investigate the adsorption strength and interaction nature between the cation and typical sulfide. [ABSTRACT FROM AUTHOR]

• CAB-PILs showed excellent catalysis performance for CO 2 cycloaddition reaction. • Cycloaddition mechanism were investigated by experimental and DFT methods. • The Lewis base site of CAB-PILs is the CO2 adsorption center. • Lewis base and Bronsted acid sites have a synergistic effect. Conjugate acid-base bi-functional PILs (CAB-PILs) with carboxylate and carboxyl branches were synthesized and used as catalysts for the cycloaddition reaction of glycidol with CO 2. Two functional ionic monomers, 3-(carboxymethyl)-1-vinyl-1H-imidazol-3-ium chloride (CEImCl) and 2-(1-vinyl-1H-imidazol-3-ium-3-yl) acetate (CCIm), were introduced into the CAB-PILs skeleton. In this case, we proved the excellent characteristics of the catalyst containing both Lewis base and Bronsted acid sites for converting CO 2 to cyclic carbonate under mild conditions. The catalyst showed good reusability and remained excellent activity after five reaction cycles. Combined with XPS, FTIR and DFT calculations, it is proved that the CCIm ionic monomer not only play the role of CO 2 absorption center, but also has synergistic effect with CEImCl in CAB-PILs to promote cycloaddition reaction. [ABSTRACT FROM AUTHOR]

[Display omitted] • Seven AA-ChCl DESs have been systematically synthesized and investigated. • The indistinguishable vibrational modes of C H or O H are identified in IR. • The chemical shifts of inactive hydrogen atoms are assigned that cannot be directly confirmed. • The liquid form of the AA-ChCl DESs mainly depends on the O H···Cl and O H···O interaction. • The O H···Cl interaction strength decreased with the alkyl chain of aliphatic acids increasing. Deep eutectic solvents (DESs) are considered as "green solvents". In this work, seven aliphatic acid-choline chloride DESs (AA-ChCl DESs) were successfully prepared. With the help of density functional theory (DFT) calculations, the experimental peaks that cannot be directly or accurately confirmed have been identified. The formation mechanism was studied with Fourier transform infrared (FT-IR) and 1H nuclear magnetic resonance (1H NMR) spectroscopy and DFT calculation. The liquid formation of the AA-ChCl DESs mainly depends on two forces, the hydrogen bonds of O H···Cl and O H···O. Among them, the O H···Cl play a leading role. The O H···Cl interaction strength decreased with the alkyl chain of aliphatic acids due to the increase of intermolecular distance, which means that the formation ability of AA-ChCl decreased gradually. It hopes that the current work can provide useful information to design DESs and expand their potential applications. [ABSTRACT FROM AUTHOR]

[Display omitted] • Crown ethers and K+ are complexed mainly by electrostatic interaction rather than coordination. • Compared with N 2 , PILs tend to absorb CO 2. • Absorbing 4 equivalents of CO 2 is unlikely for one POC. Porous liquids, a new class of materials, containing solid pores and liquid properties, have greatly aroused attention. In terms of gas absorption, porous liquids exhibit excellent advantages. Nevertheless, a variety of reports still lack the understanding of its absorption mechanism at the molecular level. Herein, we have figured out the factors contributing to the formation of porous liquids made of porous organic cages that can be dissolved in the crown ether, and the absorption mechanism of carbon dioxide, as well as CO 2 /N 2 selectivity. Through charge and Wiberg index analysis, the results show that crown ethers can interact with alkali metals to form alkali metal complexes by ion–dipole interactions, the dominant driving force of which is electrostatic interaction rather than coordination effect. Besides, the metal complexes should be regarded as a whole entity, which increases the steric hindrance of the cations and greatly reduces the probability of the crown ether blocking the cavity. The porous organic cage does provide unoccupied pores for gas storage. Furthermore, compared with N 2 , cages prefer to absorb CO 2 mainly through hydrogen bonding. It is hoped that this work can facilitate the design and synthesis of porous liquids for gas absorption and selectivity. [ABSTRACT FROM AUTHOR]

• The type IV DESs were synthesized successfully through coordination. • The type IV DESs are usded for EDSs of diesel fuel for the first time. • DESs formed by ZnCl 2 and N-methylformanilide showed high extractive performance. • The Nernst partition coefficient (K N) reached as high as 2.41. • The extraction mechanism was investigated by experimental and theoretical analysis. As promising green alternative solvents for ionic liquids, deep eutectic solvents (DESs) have been widely used in separation, catalysis, synthesis, etc. Most of the researches have focused on the application of DESs formed by hydrogen bonding interaction. In this paper, amide-based type IV DESs were synthesized from metal chloride and amides with coordination interaction, and they were used for extractive desulfurization of fuels. The experimental results showed the DES ZnCl 2 /N-methylformanilide (ZnCl 2 /MFA) had the highest desulfurization efficiency with the Nernst partition coefficient (K N) as 2.41. The extraction mechanism was firstly explored by Fourier transform infrared spectrometer (FT-IR) and 1H nuclear magnetic resonance (1H NMR). Then density functional theory (DFT) study suggested that π-π interactions and C H···π interactions contribute mainly to effective removal of DBT from fuel oil by DESs. [ABSTRACT FROM AUTHOR]

Developing an adsorbent with optimal absorption capacity for SO 2 elimination has been an important issue, yet a great challenge remains. Herein, we initiated a series of ternary deep eutectic solvents (DESs), consisting of diethylenetriamine (DETA), ethylene glycol (EG) and 1-ethyl-3-methylimidazolium chloride ([Emim]Cl) with various molar ratio for the systematical investigation of SO 2 absorption. It was found that DES with the molar ratio of 2: 1: 2 (DETA: EG: [Emim]Cl) exhibits remarkable absorption capacity (1.02 g SO 2 /g DES) and robust reusability for SO 2 at room temperature and ambient pressure, which is distinctively higher than most of the reported binary DESs so far. Moreover, FT-IR, 1H NMR, 13C NMR together with DFT calculations were adopted to clarify the absorption mechanism for SO 2. It indicates that the remarkable absorption capacity might be ascribed to the existence of multiple absorption sites. Therefore, this study offers a promising alternative for the design and preparation of highly effective absorbents for gas elimination. Highly efficient and reversible capture of SO 2 by facile synthesized ternary deep eutectic solvents with multiple absorption sites. [Display omitted] • Green DESs can be obtained through a facile procedure with relatively lower cost. • Enhanced absorption capacity and desired cycling performance can be received. • Multiple absorption sites in DES were proved by experiments and DFT calculations. [ABSTRACT FROM AUTHOR]

In this work, solubility of musk ketone in four binary solvents (methanol + ethyl acetate, isopropanol + ethyl acetate, n-hexane + ethyl acetate, n-heptane + ethyl acetate) was experimentally studied by employing the isothermal saturation method at (273.15 to 313.15) K under 101.3kPa. The results show that the solubility of musk ketone increases with the increase of temperature and the mole fraction of ethyl acetate. Hansen solubility parameter was used to reveal the solubility behavior of musk ketone. The experimental solubility data in binary solvents were correlated by the λh equation, modified Apelblat equation, Van't Hoff equation, Jouyban−Acree model, Sun model. The values of RD and RMSD indicated that these models fit the solubility data well in binary solvents. The thermodynamic properties (Δ sol H°, Δ sol S° , Δ sol G° , %ξ H and %ξ TS) were discussed by van't Hoff equation. The results show that the force for the dissolution process was entropy-driven and the dissolution process was endothermic. • The solubility of musk ketone in four binary mixed solvents was measured. • Analysis of musk ketone by DSC and XRD. • Five models were used to correlate the solubility date. • Hansen solubility parameter was used to reveal the miscibility of musk ketone. • The thermodynamic properties were discussed by van't Hoff equation. [ABSTRACT FROM AUTHOR]