Basic Ionic Liquid Research Articles

Assessing [DMAP-DABCO]AcO as an effective dual basic ionic liquid for the synthesis of Chromeno[2,3-d]pyrimidine derivatives and Exploring their Anti-Cancer activity through computational analysis

Here, we report the synthesis of a new dual basic ionic liquid viz. 1-[3-(dimethylamino)propyl]-1,4-diazabicyclo[2.2.2]octan-1-ium acetate [DMAP-DABCO]AcO, and its use as a catalyst for the synthesis of chromeno[2,3-d]pyrimidine derivatives through multi-component reaction approach involving salicylaldehyde derivatives, secondary amines and malononitrile. The ionic liquid and the chromeno[2,3-d]pyrimidine derivatives were characterized using IR, NMR, and mass spectrometry techniques. The synthesized derivatives were evaluated for their in vitro anti-cancer activity against the MCF7 cell line. The compound 4a showed the highest anti-cancer activity with an IC50 value of 65.25 µg/mL compared with the standard drug 5-FU. The anti-cancer activity of synthesized derivatives was additionally validated through computational studies, including molecular docking, density functional study (DFT), and absorption, distribution, metabolism, excretion, and (toxicity) ADME(T) analysis.

Palladium‐Catalyzed Denitrogenative Coupling of Aryldiazonium Salts with Terminal Alkynes for the Assembly of Internal Alkynes

AbstractAn N‐heterocyclic carbene palladium (NHC‐palladium)‐catalyzed denitrogenative coupling of aryldiazonium salts with terminal alkynes in ionic liquids has been accomplished. This catalytic strategy provides an effective and green synthetic protocol for the assembly of structurally diverse internal alkynes with excellent functional group compatibility and mild conditions. In the presence of 1 mol % of IMes‐Pd‐Im‐Cl2 as the catalyst, a wide range of terminal alkynes and aryldiazonium salts could be excellently tolerated. Basic ionic liquid plays a crucial role in this catalytic system, which not only acts as the green solvent, but also provides basic environment for the carbon‐carbon bond formation process. Notably, this catalytic system could be recycled up to six times and reused without significant loss of catalytic activity.

Technoeconomic and environmental impact assessment of industrial scale biodiesel production process from algal oil using a reusable basic ionic liquid magnetic nanocatalyst

A unique magnetically reusable basic ionic liquid nanocatalyst was designed to convert algal oil into biodiesel. The imidazolium-based basic ionic liquid (BIL) was immobilized onto the magnetic nanocomposite (Fe3O4-SiO2), resulting in Fe3O4-SiO2-BIL nanocatalyst with notable properties of large surface area (21.963 m2/g), high saturation magnetization (28.78 emu/g) and high thermal stability. The nanocatalyst effectively facilitated algal oil transesterification with 96.94 % biodiesel yield under methanol: oil ratio of 8.58:1 and a catalyst dosage of 4.59 % at 60.60 °C for 87.42 min. The transesterification reaction proceeded with pseudo-first-order kinetics, featuring a relatively low activation energy. The nanocatalyst showed excellent reusability for eight recycles. A techno-economic analysis demonstrated that industrial-scale biodiesel production from algal feedstock was economically viable with a minimum payback of 2.25 years. The environmental analysis revealed a low carbon footprint with the emission of 0.074 kg CO2 per kg of biodiesel produced. This research presents a sustainable approach for biodiesel production from algal feedstock facilitated by Fe3O4–SiO2–BIL nanocatalyst, offering both environmental and economic benefits.

[Triazolamine][Acetate] as a novel basic ionic liquid catalyze green synthesis of new (methylsulfonyl)benzo[h]chromen-2-amine derivatives

A new functionalized stable ionic liquid as [Triazolamine][Acetate] was prepared for the first times. The novel catalyst was well characterized by various techniques and confirmed molecular structure. The ionic liquid as a novel catalyst was carried out for the green synthesis of new (methylsulfonyl)benzo[h]chromen-2-amine derivatives via three components reaction of aldehydes, alpha-naphthol, and (methylsulfonyl)acetonitrile. A simple and an efficient procedure for the synthesis of new un-known compounds using a green and novel reusable ionic liquid as catalyst under thermal conditions in ethanol as solvent was reported. The easy preparation of ionic liquids without any toxic solvent, short reaction times, and simple work-up with excellent yields are advantages of the present research. [Triazolamine][Acetate] as new green catalyst can be reused several times without significant loss of its catalytic activity.

Boosting Visible‐Light Carbon Dioxide Reduction with Imidazolium‐Based Ionic Liquids

AbstractEfficiently generating C1 building blocks from environmentally friendly carbon sources, such as through photocatalytic CO2 reduction, is essential for fostering a sustainable circular economy. The pursuit of mild catalytic activation methods has yielded powerful catalysts that can be synergistically employed alongside various reaction media to enhance overall performance. Herein, we elucidate the influence of diverse imidazolium‐based ionic liquids as additives for visible‐light‐driven CO2 reduction with ruthenium(II)‐ and rhenium(I)‐bipyridine complexes. Our investigation reveals that incorporating ionic liquids into traditional solvents at concentrations below 10 % can markedly boost CO production while suppressing H2 generation. The best results were obtained for the highly basic ionic liquid [C2mim][OAc], resulting in a substantial rise in CO formation from 0.3 μmol/h to 5.4 μmol/h and an increase in turnover number from 3 to 59. This study underscores the cooperative influence of imidazolium‐based ionic liquids on CO2 photoreduction while circumventing their use as primary solvents, thus offering a promising avenue for sustainable chemical synthesis.

Evaluation on the recovery of lignin from basic [Ch][Lys] systems using low-cost alcohols as anti-solvents under acid-free conditions

An acid-free, high efficiency, and mild method of precipitating and separating lignin from basic ionic liquids (BIL) such as choline lysinate ([Ch][Lys]) by using alchohols (such as tert-butanol) as anti--solvents.

Solvent-free chemical upcycling of poly(bisphenol A carbonate) and poly(lactic acid) plastic waste using SBA-15-functionalized basic ionic liquids

An efficient and solvent-free chemical upcycling of polycarbonate and polylactic acid plastic waste into valuable monomers to promote a circular and resource-efficient economy using SBA-15 functionalized basic ionic liquid catalysts is presented.

Enhancement of CO2 adsorption and separation in basic ionic liquid/ZIF-8 with core-shell structure.

A novel strategy was proposed to improve the performance of gas separation in nano-materials, by fabricating a core-shell structure out of the basic ionic liquid ([Emim]2[IDA]) and zeolitic imidazolate framework (ZIF-8). The [Emim]2[IDA]/ZIF-8 exhibits a remarkable CO2 adsorption capacity of 14 cm3 g-1 at 298 K and 20 kPa, the ideal selectivity of CO2/N2 is as high as 104 and CO2/CH4 is 348 at 298 K and 100 kPa, which are much higher than the CO2 adsorption capacity (4.3 cm3 g-1) and the selectivity (SCO2/N2 = 7.4, SCO2/CH4 = 2.7) of ZIF-8. This work could pave the way for designing advanced nanostructures tailored for gas separation.

(EtO)3Si(CH2)3N+H3][CH3COO−] as Basic Ionic Liquid Catalyst Promoted Green Synthesis of Benzo[a]pyrano[2,3-c]phenazine Derivatives in Homogenous Solution

(EtO)3Si(CH2)3N+H3][CH3COO−] as Basic Ionic Liquid Catalyst Promoted Green Synthesis of Benzo[a]pyrano[2,3-c]phenazine Derivatives in Homogenous Solution

Direct Air Capture and Integrated Conversion of Carbon Dioxide into Cyclic Carbonates with Basic Organic Salts.

Direct air capture and integrated conversion is a very attractive strategy to reduce CO2 concentration in the atmosphere. However, the existing capturing processes are technologically challenging due to the costs of the processes and the low concentration of CO2. The efficient valorization of the CO2 captured could help overcome many techno-economic limitations. Here, we present a novel economical methodology for direct air capture and conversion that is able to efficiently convert CO2 from the air into cyclic carbonates. The new approach employs commercially available basic ionic liquids, works without the need for sophisticated and expensive co-catalysts or sorbents and under mild reaction conditions. The CO2 from atmospheric air was efficiently captured by IL solution (0.98 molCO2/molIL) and, subsequently, completely converted into cyclic carbonates using epoxides or halohydrins potentially derived from biomass as substrates. A mechanism of conversion was evaluated, which helped to identify relevant reaction intermediates based on halohydrins, and consequently, a 100% selectivity was obtained using the new methodology.

Diversification of product-derived ionic liquids and application in DMC synthesis without introducing any impurities

Various strongly basic ionic liquids with distinctive structures, including single and double ended quaternary ammonium and phosphorus salts, were first synthesized based on hydroxyethoxy anion (HOCH2CH2O–) from the product ethylene glycol. Nature was characterized by NMR, FTIR, TG and acid-base titration. Its alkali strength was equivalent to that of sodium methoxide, demonstrating superior alkalinity. Influences of cation structures and C1-C4 alcohols structures on transesterification efficiency were investigated. Under mild conditions (68 °C for 5 min), DMC yield was 42.8% with a TOF value of 2853.6 h−1 when [TBAB]OCH2CH2OH as catalyst with only 0.18% EC molar content, indicating good catalytic performance. Comparison was made for reaction results between the synthesized catalysts and reported catalysts in literatures. The reaction mechanism was further deduced. Activation energies of positive and reverse reactions were determined as Ea+=32.0 kJ·mol−1 and Ea-=15.3 kJ·mol−1 through kinetics calculation. Relying on its decomposability and recyclability of decomposition products, a new catalyst circulation process without introducing any impurities was proposed and verified.

Structure and catalytic performance relationship of ionic liquids as recyclable alcoholysis catalysts for green preparation of ethylene‐vinyl alcohol copolymer

AbstractAlcoholysis is an important reaction for the current industrial production of ethylene‐vinyl alcohol (EVOH) copolymers. Herein, two series of ionic liquids (ILs), acidic and basic ones, were used as eco‐friendly catalysts for alcoholysis of ethylene‐vinyl acetate (EVA) copolymer. The effects of the reaction parameters (catalyst loading, n(CH3OH)/n(Ac) and reaction time), EVA composition, and nitrogen flow on the alcoholysis were systematically investigated. A nearly 100% of alcoholysis degree was achieved using acidic ILs ([BHSO3MIm][HSO4]) under the optimum conditions (3.0 mol% catalyst loading relative to the VA units in EVA, n(CH3OH)/n(Ac) = 30, 70°C, 6 h). Moreover, [BHSO3MIm][HSO4] could be reused at least five times without the decrease of catalytic activity, showing excellent recyclability. The interactions between IL and the substrate methanol and the model compound ethyl acetate were investigated by Fourier transform infrared spectroscopy and proton nuclear magnetic resonance techniques, and on the basis of these results, the plausible mechanisms of acidic and basic ILs catalyzed alcoholysis of EVA were proposed.

Process optimization and technoeconomic assessment of biodiesel production by one-pot transesterification of Ricinus communis seed oil

In the present study, Ricinus communis seed oil with high free fatty acid content was utilized for the one-pot biodiesel production using 1-(2,3-dihydroxy)-propyl-3-methylimidazolium hydroxide, a basic ionic liquid catalyst. The 97.83% biodiesel yield was obtained at the optimized conditions of 6.26 % (w/w) of catalyst concentration, 10.51:1 M ratio of methanol to oil, 57.87 °C temperature and reaction time of 61.01 min. The transesterification of Ricinus communis seed oil to biodiesel exhibited an activation energy of 37.60 kJ/mol. The technoeconomic analysis, the profitability and the sensitivity analysis were investigated for the simulated process design. The technoeconomic analysis reported a total revenue of 20,455,431 $/yr, with gross margins, ROI, payback period, IRR, and NPV of 23.54%, 35.72%, 2.8 years, 28.20%, and 19,287,000 $, respectively. According to the sensitivity analysis, the two most important factors determining the economic viability of the simulated process are Ricinus communis seed oil cost and biodiesel selling price.

Fischer Esterification of Benzoic Acid and Polyhydric Alcohols Catalyzed by Basic Ionic Liquids of Bisimidazolium Tungstates

AbstractFischer esterification referred to the reaction of carboxylic acids and alcohols, which was generally catalyzed by Brönsted or Lewis acidic catalysts. Basic ionic liquids with the nucleophilic anion were generally considered incapable of catalyzing this reaction due to sufficiency of electrons or the lack of ionizable protons. Herein, bisimidazolium tungstates were found be able to catalyze Fischer esterification of ethylene glycol (EG) and benzoic acid relying on the nucleophilic WO42− anion. The mechanism studies indicated that C6H5COO− and H−WO42− anionic intermediate was formed between benzoic acid and WO42− via hydrogen‐bond interaction under the influence of hydroxyl of EG. This intermediate could further release H atom to accelerate the reaction speed of Fischer esterification, which was similar catalytic process to that of Brönsted acidic catalysts. Furthermore, other nucleophilic anions (CO32−, OH−, OAc−, C6H5COO−) had little catalytic capacity in the reaction. This suggested that the strength of anionic nucleophilic ability played an important role in the esterification reaction.

Aryloxy Ionic Liquid-Catalyzed Homogenous Esterification of Cellulose with Low-Reactive Acyl Donors.

Ionic liquids (ILs) are recyclable, non-volatile, and can dissolve cellulose, a natural polymer that is insoluble in versatile solvents. Therefore, ILs have been used to modify cellulose. However, 1-ethyl-3-methylimidazolium acetate (EmimOAc), a commercially available IL often used to dissolve and modify cellulose to prepare cellulose-based materials, causes the undesired introduction of an acetyl group derived from the acetate anion of EmimOAc onto the hydroxy group of cellulose during esterification. In this study, for cellulose esterification, we prepared aryloxy ILs as non-carboxylate-type and basic ILs, which can theoretically prevent the undesired introduction of an acyl group from the IL onto the hydroxy group of cellulose. The optimized 1-ethyl-3-methylimidazolium 2-pyridinolate (Emim2OPy) and mixed solvent system achieved rapid cellulose esterification (within 30 min) with an excellent degree of substitution (DS) value (up to >2.9) derived from the employed low-reactive vinyl esters and bio-based unsaturated aldehydes, without any undesired substituent introduction from side reactions.

Automation of liquid crystal phase analysis for SAXS, including the rapid production of novel phase diagrams for SDS-water-PIL systems.

Lyotropic liquid crystal phases (LCPs) are widely studied for diverse applications, including protein crystallization and drug delivery. The structure and properties of LCPs vary widely depending on the composition, concentration, temperature, pH, and pressure. High-throughput structural characterization approaches, such as small-angle x-ray scattering (SAXS), are important to cover meaningfully large compositional spaces. However, high-throughput LCP phase analysis for SAXS data is currently lacking, particularly for patterns of multiphase mixtures. In this paper, we develop semi-automated software for high throughput LCP phase identification from SAXS data. We validate the accuracy and time-savings of this software on a total of 668 SAXS patterns for the LCPs of the amphiphile hexadecyltrimethylammonium bromide (CTAB) in 53 acidic or basic ionic liquid derived solvents, within a temperature range of 25-75 °C. The solvents were derived from stoichiometric ethylammonium nitrate (EAN) or ethanolammonium nitrate (EtAN) by adding water to vary the ionicity, and adding precursor ions of ethylamine, ethanolamine, and nitric acid to vary the pH. The thermal stability ranges and lattice parameters for CTAB-based LCPs obtained from the semi-automated analysis showed equivalent accuracy to manual analysis, the results of which were previously published. A time comparison of 40 CTAB systems demonstrated that the automated phase identification procedure was more than 20 times faster than manual analysis. Moreover, the high throughput identification procedure was also applied to 300 unpublished scattering patterns of sodium dodecyl-sulfate in the same EAN and EtAN based solvents in this study, to construct phase diagrams that exhibit phase transitions from micellar, to hexagonal, cubic, and lamellar LCPs. The accuracy and significantly low analysis time of the high throughput identification procedure validates a new, rapid, unrestricted analytical method for the determination of LCPs.

A Gemini basic ionic liquid and functionalized cellulose nanocrystal-based mixed matrix membrane for CO2/N2 separation.

Owing to the adverse environmental impact, carbon capture and separation have gained tremendous interest throughout the globe. Herein, a CO2/N2 gas separative mixed matrix membrane containing amine functionalized cellulose nanocrystals and a Gemini basic ionic liquid has been developed, which exhibits the highest permeance of 21 033 GPU and moderate selectivity of 21.3.

Preparation of functionalised heteropolyacid ionic liquids and their application in catalytic degradation of bottle-grade polyester

This research study is related to an environmentally friendly process method for catalytic degradation of bottle-grade PET by using ionic liquid catalysts.

Basic Ionic Liquid [Bmim]OH as Efficient Greener Medium for the Oxidation α-Hydroxy Ketone Compounds and Alcohols to Carbonyl Compounds with Potassium Permanganate

In this work, a convenient and greener procedure for synthesizing 1,2-diarylethane-1,2-dione derivatives as well as the oxidation of primary and secondary alcohols was explored using an oxidizing agent (KMnO4) in a basic ionic liquid of 1-butyl-3-methylimidazolium hydroxide ([Bmim]OH) as greener medium. The selective oxidation of α-hydroxy ketone compounds together with primary and secondary alcohols in the presence of KMnO4 in [Bmim]OH afforded corresponding carbonyl compounds of 1,2-diarylethane-1,2-dione derivatives and aldehydes or ketones in high yields (85-97% and 83-97%, respectively). The reactions are mild, fast, and efficient. Moreover, KMnO4 in [Bmim]OH medium was easily recovered and reused for at least four additional reactions without significant loss of efficiency with a consistent yield of about 80%.

Basic ionic liquid grafted on magnetic nanoparticles: An efficient and highly active recyclable catalyst for the synthesis of β-nitroalcohols and 4H-benzo[b]pyrans

In this study, we have synthesized Fe3O4@SiO2 (FS) immobilized 1,4-diazabicyclo[2.2.2] octane (DABCO) based-basic ionic liquid functionalized magnetic nanoparticles. The synthesized nanocomposite was characterized by various physicochemical and morphological techniques such as - FTIR, Powder-XRD, VSM, BET, CHN, TEM and SEM-EDX. Its application was checked as an active and highly efficient green catalyst by utilizing it in the synthesis of various 4H-benzo[b]pyran and β-nitroalcohol derivatives. The prepared heterogeneous catalyst was found to be thermally stable and highly cost-effective for the base-promoted organic transformation reactions producing excellent yields in short reaction times. In addition to this, the prepared magnetic nanocomposite could be readily recovered by applying a magnetic field and can be recycled up to eight catalytic cycles without any noteworthy loss in its performance.