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Eutectic solvents are tunable for targeted applications through the functional groups in their hydrogen bond acceptor (HBA) and hydrogen bond donor (HBD) components, as well as the HBA : HBD composition ratio. This study examines the properties of choline-based eutectics containing imidazole, phenol, pyrrole-2-carbonitrile, and 1,2,4-triazole HBAs, and ethylene glycol, 1,2-propylene glycol, and ethanolamine HBDs. The viscosity, conductivity, degree of hydrogen bonding, thermal stability, and solvatochromic properties are examined as a function of HBA, HBD, and the composition. These studies revealed a predominant dependence of physical properties on the HBD and determined that the strong hydrogen bonding in phenol and imidazole-based systems lead to higher viscosities and lower conductivities – critical parameters for CO2 capture and electrochemical conversion. The developed eutectic solvents were further evaluated in terms of their CO2 capture capacities and electrochemical stabilities. Solvatochromic properties were found to correlate with CO2 capacities, demonstrating the tunability of these solvents for CO2 capture. The quantitative structure–property relationship (QSPR) analysis demonstrated the ability to predict viscosities and CO2 capture capacities (<25% deviation) through a multi linear regression method utilizing five molecular descriptors. This work highlights the role of functionalized HBAs and HBDs in the physical, thermal, and electrochemical properties of eutectic solvents as they relate to CO2 capture and electrochemical processes. [ABSTRACT FROM AUTHOR]

The development of convenient and practical synthetic strategies for constructing bioactive molecules without metal residues is of great interest in organic synthesis. Herein, a metal-free, operationally simple, and scalable electrooxidation-induced three-component cross-coupling method to access 3-thio/selenophosphorylated imidazole derivatives from readily available isothiocyanates/isoselenocyanates, isocyanates, and H-phosphonates is first reported. More than 30 examples have been provided with good to moderate yields. Importantly, the readily accessible compounds could be used as pesticides (wheat anti-locust) with good biocompatibility (5d-stimulated RAW 264.7 macrophages, IL-6 = 5.3 pg mL−1, THF-α = 79.8 pg mL−1), reiterating the importance of the developed electrochemical methodology. [ABSTRACT FROM AUTHOR]

The simultaneous achievement of large surface areas and high IL contents in porous materials are highly beneficial for efficient carbon dioxide (CO2) capture and atmospheric fixation. Herein, a series of porous hypercrosslinked poly(ionic liquid)s (HPILs) are successfully developed through a two-step synthetic strategy, including free radical self-polymerization of a specific benzyl bromide-tethered imidazole ionic liquid (IL) to fabricate a linear PIL as a precursor, and a subsequent Friedel–Crafts alkylation between the precursor and the crosslinker for hypercrosslinking. The HPILs featured large surface areas of up to 855 m2 g−1 along with a hierarchically nanoporous structure, high IL contents (2.19–2.91 mmol g−1) and satisfactory CO2-philic properties. By virtue of the combined advantages, HPILs served as metal-free heterogeneous catalysts for solvent-additive-free CO2 cycloaddition with epichlorohydrin at 80 °C and 0.1 MPa CO2 for 24 h, presenting high catalytic activity and stable reusability. A high yield of 99.0% coupled with a turnover frequency (TOF) of 6.0 h−1 was achieved, much higher than most of the reported metal-free heterogeneous catalysts, even superior to homogeneous analogues. Furthermore, various epoxides, including large-sized epoxides, were effectively converted into carbonates with high yields, affording good substrate applicability. This work reports a facile and universal approach for the construction of porous HPILs with both great porosities and high IL contents towards efficient chemical fixation of CO2 under mild conditions. [ABSTRACT FROM AUTHOR]

Many studies have been focused on the selective separation of hydrogen chloride (HCl) gas, but its capture and conversion in situ is still at a standstill. Herein, a pioneering attempt to employ a deep eutectic solvent (DES) as a "courier" to combine HCl capture and in situ conversion has been presented. Impressively, the highest HCl absorption capacity is determined to be 3.95 mol/mol, or 0.672 g/g, or 18.4 mol kg-1 at 1.0 bar and 30 °C in a binary DES based on EmimCl/Im. The internal transmission mechanism between imidazole and HCl was revealed by DFT-based theoretical calculations. The reaction between HCl and epoxides achieved 99% conversion under mild conditions in the absence of a solvent, making the entire reaction ecologically benign. Water extraction was used to recycle the DES from the reaction system, and it maintained good catalytic performance after ten cycles. The exhaust HCl-SO2 mixed gases from the sucralose industry were further investigated, which proved the possibility of selective conversion of HCl. Furthermore, a plausible reaction-separation-integration (RSI) strategy was proposed to avoid the high energy consumption of desorption, which provides a novel insight into future applications. It is believed that the good results, combined with the simplicity of operation and the high recyclability of the catalyst, make this green method environmentally friendly and cost-effective. This work reveals an effective approach for the coupling of HCl capture and conversion under mild conditions. [ABSTRACT FROM AUTHOR]

An expeditious one-pot method for the synthesis of highly substituted 5-aminoimidazoles from glyoxals, anilines, and amidines was evaluated under metal/catalyst-free conditions operative at room temperature. The present protocol constitutes an environmentally friendly approach for the synthesis of highly substituted 5-aminoimidazoles, which are important building blocks of several bioactive and medicinal compounds. The readily and commercially available starting materials can be quickly assembled into imidazoles using this protocol and scaling up this process does not require chromatographic purification. Additionally, the reaction of 5-aminoimidazole with 2-bromobenzoyl chloride can provide a novel imidazo[5,1-b]quinazolin-9(4H)-one, thus showcasing the applicability of this protocol. [ABSTRACT FROM AUTHOR]