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Aggregation‐induced emission (AIE) materials have drawn great attention for applications as organic light‐emitting diodes (OLED) and probes. The applications are, however, restricted by the complex syntheses and hydrophobic properties. Herein, a one‐step synthesis of an AIE material based on imidazole hydrazone is assessed. Protonation of the imidazole‐H leads to emission color change from yellow to green in the solid state. The emission color is recovered upon imidazole‐H+ deprotonation. Moreover, the emission wavelength shifts from 532 to 572 nm by anion exchange. In addition, an enhanced emission (ΦF up to 22.6 %) was obtained with the Br− anion compared with NTf2−, SbCl5−, PF6−, and OTf− anions. X‐ray crystallography studies together with theoretical calculations show that the enhanced emission of hydrazone salts arises from strong hydrogen bonding between the hydrazone proton and the halide ion (Cl− or Br−). [ABSTRACT FROM AUTHOR]

To illuminate the influence mechanism of anionic structure of ionic liquids (ILs) on the adsorption performance of surface molecularly imprinted polymers (MIPs), in this work, six newly designed MIPs were prepared on the surface of amino-poly(styrene-divinylbenzene) particles by using imidazolium ILs with the same cation [C 4 mim] + but different anions (Cl, CH 3 SO 3 , PF 6 , BF 4 , C 4 F 7 O 2 , C 4 F 9 SO 3 ) as template molecules, methacrylic acid as functional monomer, and ethylene dimethacrylate as cross-linker. The resulting MIP materials were characterized by IR and SEM, and the influence of hydrogen bond accepting ability of anions on the adsorption performance of the MIPs for the ILs was investigated in acetonitrile. It was found that adsorption capacity of the MIPs towards the ILs decreased in the order MIP [C4mim][Cl]  > MIP [C4mim][C4F7O2]  ≥ MIP [C4mim][BF4] and MIP [C4mim][CH3SO3]  > MIP [C4mim][C4F9SO3]  > MIP [C4mim][PF6] , which is in good agreement with the ability of anions of the ILs to form hydrogen bonds. Ultraviolet, 1 H-NMR and 35 Cl-NMR spectroscopy was then used to study the interactions of anions of the ILs with the functional monomer. It was found that the hydrogen bond interaction between anions of the ILs and acidic proton of the functional monomer was the main driving force for the high adsorption selectivity of the imprinted polymers, and the stronger hydrogen bond interaction indicates higher binding capacity and higher selectivity of the polymers towards the ILs. It was also verified that the ILs with stronger hydrogen bond accepting ability of anions could be selectively extracted by the corresponding IL-MIPs. These results may provide new insight into the recognition mechanism of MIPs for ILs, and are also useful for the rational design of this new class of imprinting materials. [ABSTRACT FROM AUTHOR]

A novel strategy based on the concept of preorganization and cooperation has been designed for a superior capacity to capture low-concentration CO2 by imide-based ionic liquids. By using this strategy, for the first time, an extremely high gravimetric CO2 capacity of up to 22 wt % (1.65 mol mol−1) and excellent reversibility (16 cycles) have been achieved from 10 vol. % of CO2 in N2 when using an ionic liquid having a preorganized anion. Through a combination of quantum-chemical calculations and spectroscopic investigations, it is suggested that cooperative interactions between CO2 and multiple active sites in the preorganized anion are the driving force for the superior CO2 capacity and excellent reversibility. [ABSTRACT FROM AUTHOR]

The inherent structure tunability, good affinity with CO2, and nonvolatility of ionic liquids (ILs) drive their exploration and exploitation in CO2 separation field, and has attracted remarkable interest from both industries and academia. The aim of this Review is to give a detailed overview on the recent advances on IL-based materials, including pure ILs, IL-based solvents, and IL-based membranes for CO2 capture and separation from the viewpoint of molecule to engineering. The effects of anions, cations and functional groups on CO2 solubility and selectivity of ILs, as well as the studies on degradability of ILs are reviewed, and the recent developments on functionalized ILs, IL-based solvents, and IL-based membranes are also discussed. CO2 separation mechanism with IL-based solvents and IL-based membranes are explained by combining molecular simulation and experimental characterization. Taking into consideration of the applications and industrialization, the recent achievements and developments on the transport properties of IL fluids and the process design of IL-based processes are highlighted. Finally, the future research challenges and perspectives of the commercialization of CO2 capture and separation with IL-based materials are posed. [ABSTRACT FROM AUTHOR]

The separation and recycling of catalyst and cocatalyst from the products and solvents are of critical importance. In this work, a class of functionalized ionic liquids (ILs) were designed and synthesized, and by tuning the hydrophilicity and hydrophobicity of cation and anion, respectively, these ILs could reversibly transfer between water and organics triggered upon undergoing a temperature change. From a combination of multiple spectroscopic techniques, it was shown that the driving force behind the transfer was originated from a change in conformation of the PEG chain of the IL upon temperature variation. By utilizing the novel property of this class of ILs, a highly efficient and controllable CuI-catalyzed cycloaddition reaction was achieved wherein the IL was used to entrain, activate, and recycle the catalyst, as well as to control the reaction. [ABSTRACT FROM AUTHOR]

[Display omitted] • Pyridinolate-based functional ILs with different structures were designed for SO 2 capture. • Anion order of SO 2 capacity is [4-PyO] > [3-PyO] > [2-PyO]. • Cation order of SO 2 capacity is [P 66614 ] > [P 4442 ] > [TMG]. • Viscosity of system increased first and then decreased with the increase of absorption capacity. A series of pyridinolate anion-functional ionic liquids (ILs) containing different kinds of cations were designed and prepared, including tri- n -hexyltetradecylphosphonium [P 66614 ], tri- n -butylethylphosphonium [P 4442 ], and 1,1,3,3-tetramethylguandinium [TMG] cations and pyridinolate [PyO] anions with different N positions. Densities and viscosities at different temperatures were measured because of their importance for the absorption of SO 2. Effect of different structures on the absorption of SO 2 was studied, including the type and the alkyl chain length of cations, and the N positions of [PyO] anions (2-, 3-, and 4-). Additionally, effects of SO 2 concentration and temperature for absorption were investigated. Especially, up to 6.00 and 2.53 mol SO 2 per mole IL could be obtained by [P 66614 ][4-PyO] at 1 bar and 0.1 bar of SO 2 , respectively, when absorptions performed at 20 °C. The results indicate that (1) the aprotic cations weakened the cation⋯anion interaction and resulted in the released active sites on the anions, and (2) N position has an influence on charge distribution of [PyO] anions and resulted in the tunable absorption of SO 2. Reversible SO 2 absorption and [P 66614 ][4-PyO] regeneration could be performed several times without losing efficiency. Furthermore, the mechanism of absorption was studied through FT-IR and NMR methods and the results showed that the absorption of SO 2 by [P 66614 ][4-PyO] includes physisorption and chemisorption. [ABSTRACT FROM AUTHOR]