Synthesis Of Ionic Liquids Research Articles

Synthesis of chiral phosphine-functionalized ionic liquids and their application in asymmetric hydrogenation

Abstract The present report prepared three novel chiral phosphine-functionalized polyetherimidazolium ionic liquids through ion-exchange reactions of chiral sulfonated BINAP ligands and hydroxyl-functionalized polyetherimidazolium ionic liquids grounded on the phosphine ligand-ionic liquid integration. Using these synthetics, methyl acetoacetate was subjected to asymmetric homogeneous hydrogenation catalyzed by ruthenium. The structural characterization of the three chiral phosphine-functionalized polyetherimidazolium ionic liquids was conducted using 1H NMR, 13C NMR, and 31P NMR in combination with HR-MS. Compared with their precursor sulfonated BINAP, the prepared chiral phosphine-functionalized ionic liquids exhibited comparable or better catalytic activity and enantioselectivity.

The use of green protic ionic liquids in the crystallization of isoniazid: Evaluation of physicochemical and biological properties of drug

This study evaluated the synthesis of protic ionic liquids (PILs), 2-hydroxy ethylammonium formate (2-HEAF) and 2-hydroxy ethylammonium acetate (2-HEAA), and their applicability in the crystallization process of the active pharmaceutical ingredient isoniazid (INH) as anti-solvent. Isoniazid is an antibiotic used in the treatment of tuberculosis infections, being used as a first-line chemotherapeutic agent against Mycobacterium tuberculosis. Futhermore, this investigation was conducted in order to evaluate how these PILs can influence the habit, solubility, stability, and therapeutic efficiency of the obtained isoniazid crystals. The 2-HEAF and 2-HEAA PILs were easily formed in reactions between ethanolamine and carboxylic acids (formic or acetic acid), and they have no toxicity against Artemia salina. The PILs were able to crystallize isoniazid, influencing the crystal habit and size. The greatest variations in the hydrogen signals of the NH2 and NH groups of the amine and low variations in the chemical shifts of the hydrogens of the cation of the ethanolamine group from 2-HEAA and 2-HEAF indicate that PILs establish possibly weak interactions with INH. The obtained crystals were amorphous and showed higher solubility in water than standard INH. Moreover, these crystals showed therapeutic efficiency inantimycobacterial activity to inhibit the growth of Mycobacterium tuberculosis. The INH:2-HEAF only degraded 5.1 % (w/w), however, INH:2-HEAA degraded 32.8 % (w/w) after 60 days in an accelerated atmosphere. Then, the 2-HEAA and 2-HEAF were able to crystallize isoniazid, being a new application for these PILs. The used PILs also influenced the characteristics of isoniazid crystals.

Role of ionic liquids in the electrodeposition of metals

Green chemistry techniques have gained significant importance in advancing chemical engineering and processes in the modern era, contributing to the implementation of sustainable development strategies. Ionic liquids (ILs) at room temperature have emerged as versatile solvents in catalysis, separation science, and electrochemistry. Conventional synthesis of ILs typically involves a two-step process using refluxing solvents, which is time-consuming and requires large amounts of organic solvents. This study investigates the synthesis of alkylmethylimidazolium salts by the co-heating of haloalkanes and 1-methylimidazole, highlighting the role of ILs in green chemistry, particularly in the electrodeposition of metals. The objective of this research is to explore the impact of ILs on the electrodeposition process, aiming to develop environmentally friendly and efficient metal deposition methods. The methodology involves the preparation of ILs through a facile and sustainable approach, followed by the characterization of their physicochemical properties. The ILs are then utilized as electrolytes for metal electrodeposition, and the resulting metal films are analyzed for their morphology, structure, and properties. The findings of this study demonstrate the significant influence of ILs on metal electrodeposition. The ILs exhibit excellent solvation properties, facilitating the reduction and deposition of metals with improved control over morphology and structure. Additionally, the ILs offer the advantage of reduced environmental impact compared to traditional organic solvents. The main innovation lies in the application of ILs as green solvents in metal electrodeposition, contributing to the development of sustainable and efficient processes in the field of green chemistry.

Tracheal regeneration and mesenchymal stem cell augmenting potential of natural polyphenol-loaded gelatinmethacryloyl bioadhesive

Hydrogels incorporating natural biopolymer and adhesive substances have extensively been used to develop bioactive drugs and to design cells encapsulating sturdy structure for biomedical applications. However, the conjugation of the adhesive in most hydrogels is insufficient to maintain long-lasting biocompatibility inadequate to accelerate internal organ tissue repair in the essential native cellular microenvironment. The current work elaborates the synthesis of charged choline-catechol ionic liquid (BIL) adhesive and a hydrogel with an electronegative atom rich polyphenol (PU)-laden gelatinmethacryloyl (GelMA) to improve the structural bioactivities for in vivo tracheal repair by inducing swift crosslinking along with durable mechanical and tissue adhesive properties. It was observed that bioactive BIL and PU exhibited potent antioxidant (IC 50 % of 7.91 μg/mL and 24.55 μg/mL) and antibacterial activity against E. coli, P. aeruginosa and S. aureus. The novel integration of photocurable GelMA-BIL-PU revealed outstanding mechanical strength, biodegradability and sustained drug release. The in vitro study showed exceptional cell migration and proliferation in HBECs, while in vivo investigation of the GelMA-BIL-PU hydrogel on a rat's tracheal model revealed remarkable tracheal reconstruction, concurrently reducing tissue inflammation. Furthermore, the optimized GelMA-BIL-PU injectable adhesive bioink blend demonstrated superior MSCs migration and proliferation, which could be a strong candidate for developing stem cell-rich biomaterials to address multiple organ defects.

Design and synthesis of SO3H-based ionic liquids for direct catalytic conversion of straw to levulinic acid

The utilization of ionic liquids (ILs) in the conversion of lignocellulose to levulinic acid (LA) is a significant pathway in the field of bio-refinery. In this study, a series of sulfonic-based ILs with elongated alkyl chains were synthesized using density functional theory. These ILs were then utilized for the conversion of straw into LA in a single reaction vessel. The yield of LA was compared between a single solvent (water) and a biphasic system comprising water and methyl isobutyl ketone (MIBK). Among the investigated ILs, [C3SO3HEim]Cl exhibited a higher yield of LA, reaching up to 11.3 wt% in the aqueous phase and 17.8 wt% in the MIBK-water biphasic system. Furthermore, [C3SO3HEim]Cl displayed a high catalytic efficiency (90.4%) and a yield of LA (16.3 wt%) after 5 cycles. These findings suggest that the elongation of alkyl side chains in ILs enhances the solubility of cellulose and increases the yield of LA. The MIBK-water biphasic system promotes the rehydration of hydroxymethylfurfural (HMF) and reduces the residence time of LA in the aqueous phase, thereby optimizing its yield. This innovative approach involving ILs and the MIBK-water biphasic system presents a novel perspective for the production of LA from biomass.

Tris(2-hydroxyethyl)ammonium-Based Protic "Ionic Liquids": Synthesis and Characterization.

The proton transfer associated with the synthesis of protic ionic liquids (PILs) is often incomplete, meaning that the parent compounds may coexist with the ionic species. However, PILs are proposed for many applications as pure compounds without analysis of their ionicity. This work focuses on tris(2-hydroxyethyl)ammonium-based PILs with lactate, hydrogen succinate, hydrogen malate, and dihydrogen citrate anions. The interest of these anions lies in their low toxicity and capacity to disrupt the hydrogen-bonding network inherent to biopolymers. To improve current synthesis methods of this kind of PILs, which frequently lead to impurities derived from decomposition of reactants, working in the absence of solvents and at moderate temperatures is proposed. Through NMR studies, the ionicity of these systems was found to be low, from 20% to 86%, so the widely used term "ionic liquid" is not rigorous and must be used with caution. The un-ionized acid and base species coexist with the corresponding ionic forms, and this has to be considered in the studies involving these chemicals. The thermal characterization of the PILs was carried out. The influence of the anion on the thermal stability was found to be low. Isothermal thermogravimetric analysis showed that mass loss of these PILs starts at temperatures close to 350 K.

Research on synthesis of imidazole-based ionic liquids as metal corrosion inhibitors

Ionic liquids (ILs) have gained significant attention in recent years as potential corrosion inhibitors to various applications. Traditional corrosion inhibitors, such as organic compounds and inorganic salts, have limitations in terms of toxicity, volatility, and environmental impact. However, ionic liquids offer a promising alternative. Ionic liquids are salts that exist in a liquid state at or below 100 degrees Celsius. They typically comprise an organic cation and an inorganic or organic anion. The unique combination of a liquid state and ionic nature gives them several advantageous properties, such as high thermal stability, low vapor pressure, and tunable physicochemical properties. Additionally, the charged nature of the ionic liquid allows for electrochemical interactions with the metal surface, further enhancing corrosion inhibition. In this paper, imidazole-based ionic liquids were synthesized by alkylation of imidazole derivatives using 1-bromohexadecane. The anti-corrosion properties of the material were evaluated using the weight method and potentiodynamic polarization method. Results showed that the synthesized ILs are good corrosion inhibitor for CT3 steel.

Cover Feature: Ionic liquid templated synthesis of cobalt‐substituted mesoporous aluminophosphates: A novel heterogeneous catalyst for selective oxidation of cyclohexane to cyclohexanol (ChemCatChem 8/2024)

Cover Feature: Ionic liquid templated synthesis of cobalt‐substituted mesoporous aluminophosphates: A novel heterogeneous catalyst for selective oxidation of cyclohexane to cyclohexanol (ChemCatChem 8/2024)

New Insights into the Hygroscopic Character of Ionic Liquids: Study of Fourteen Representatives of Five Cation and Four Anion Families.

Over the past three decades, the synthesis of new ionic liquids (ILs) and the expansion of their use in newer applications have grown exponentially. From the beginning of this vertiginous period, it was known that many of them were hygroscopic, which in some cases limited their use or altered the value of their measured physical properties with all the problems that this entails. In an earlier article, we addressed the hygroscopic grade achieved by the ILs 1-ethyl-3-methylimidazolium chloride, 1-ethyl-3-methylimidazolium bromide, 1-ethyl-3-methylimidazolium methyl sulfate, 1-ethyl-3-methylimidazolium ethyl sulfate, 1-ethyl-3-methylpyridinium ethyl sulfate, 1-ethyl-3-methylimidazolium tosylate, 1-ethyl-3-methylimidazolium tetrafluoroborate, 1-butyl-3-methylimidazolium tetrafluoroborate, 1-dodecyl-3-methylimidazolium tetrafluoroborate, 1-butyl-3-methylpyridinium tetrafluoroborate, 1-butyl-1-methylpiperidinium bis(trifluoromethyl sulfonyl)imide, 1-methyl-1-propylpyrrolidinium bis(trifluoromethyl sulfonyl)imide, 1-butyl-1-methylpyrrolidinium bis(trifluoromethyl sulfonyl)imide, and methyl trioctyl ammonium bis(trifluoromethyl sulfonyl)imide. The objective was to determine the influence of the chemical nature of the compounds, exposed surface area, sample volume, agitation, and temperature. For this purpose, we exposed the samples to abrupt increases in relative humidity from 15 to 100% for days in an atmosphere chamber and then proceeded with the reverse process in a gentle manner. The results show that the sorption of water from the atmosphere depends on the nature of the IL, especially the anion, with the chloride anion being of particular importance (chloride ≫ alkyl sulfates~bromide > tosylate ≫ tetrafluoroborate). It has also been proven for the EMIM-ES and EMIM-BF4 samples that the mechanism of moisture capture is both absorption and adsorption, and that the smaller the exposed surface area, the higher the ratio of the mass of water per unit area.

Synthesis of polymer ionic liquids of the ionene type

New regularities have been discovered in the synthesis of polymer ionic liquids and ionene-type ionic liquids based on polyionenes derived from tetrahydro-1,4-oxazine. The methods for regulating the molecular weight of the synthesized polymers have been improved by varying the nature and composition of the solvent, as well as the concentration of the starting monomers. These improvements have resulted in the creation of new and promising materials. For the first time, we investigated the effects of temperature, solvent type and composition, chemical structure, and concentration of polyionenes derived from tetrahydro-1,4-oxazine on their behavior in water and water-ethanol solutions, as well as the shape of macromolecules in different solvents. Newly synthesized polymeric ionic liquids and ionene ionic liquids with an ionic conductivity of 10–2–10–5 S•cm–1 and a glass transition temperature range of –1500С–150С exhibit five to six orders of magnitude higher ionic conductivity compared to known analogues.

Facile synthesis of magnetic ionic liquid with magnetic tuning electrochemical performance

Facile synthesis of magnetic ionic liquid with magnetic tuning electrochemical performance

Construction of trifloaluminate ionic liquid catalyst on the silica surface dedicated for continuous flow Diels-Alder synthesis

Supported ionic liquid phases (SILP) are efficiently use for the construction of highly active, heterogeneous and recyclable catalysts. In this study, three strategies towards chemical immobilization of trifloaluminate ionic liquid catalyst into microporous/mesoporous silica support were investigated. The order of silica surface modification with trifloaluminate ILs components had crucial influence on the catalytic activity and stability which was tested in the model Diels-Alder reaction between isoprene and maleic anhydride in acetonitrile at room temperature. The best catalytic performance (maleic anhydride conversion > 97% in ten reaction cycles) was achieved for catalyst created through the synthesis of trifloaluminate ionic liquid in the first step with further bounding to the silica surface using 25 wt% of ionic liquid loading. The effective transformation of the Diels-Alder reaction to continuous flow synthesis led to 97% maleic anhydride conversion over 432 h with a TOF of 104.3 h−1 and significantly improved process sustainability.

Catalytic One-pot Solvent Free Synthesis, Biological Activity, and Docking Study of New Series of 1, 3-thiazolidine-4-one Derivatives Derived from 2- (P-tolyl) Benzoxazol-5-amine.

In this study, a simple triethylammonium salt of phosphoric acid (triethylammonium dihydrogen phosphate) (4) in the liquid state was utilized as an inexpensive, efficient one-pot three components, solvent-free synthesis of thiazolidine-4-one derivatives, with good to excellent yields. Techniques such as FT-IR, 1H-NMR, 13C-NMR, 13C-NMR-DEPT-135, and MS. were used for the structural elucidation. The high biotic efficiency of the newly obtained compounds was confirmed by in vitro antimicrobial action against Gram-positive (S. Aureus), Gram-negative bacteria (P. Aeruginosa and E. Coli) and antifungal activity (C. Albicans) via microplate titer dilution technique. Finally, a molecular docking study was performed with a resolved crystal structure of S. Aureus D-alanine alanyl carrier protein ligase (PDB ID: 7VHV). This investigation aimed to synthesize a new series of thiazolidine-4-one derivatives combined with benzoxazole moiety. Ionic liquid assistance one-pot solvent-free synthesis method used to synthesize a new series of thiazolidine-4-one derivative 10(a-e). Structural identification of new synthesis and biological evaluation via techniques of (IR, 1H-NMR, 13C-NMR, 13C-NMR-DEPT-135, and MS). Ionic liquid is utilized as an inexpensive, efficient one-pot three-component solvent-free synthesis of thiazolidine-4-one derivatives with good to excellent yields. Most of the synthesized compounds showed high biological and anti-fungal activity, in line with the docking study against mentioned microorganism and crystal structure of PDB (ID: 7VHV), respectively.

Synthesis and characterization of a di-methacrylated polymerizable ionic liquid through two-step esterification and ion exchange process

An effective two-step synthesis for the di- methacrylation of 2-hydroxylethylammonium chloride ionic liquid was developed in the presence of methacrylic anhydride. The esterification process was performed through the hydroxyl moiety and the side product methacrylic acid was effectively captured through an ion exchange process via sodium bicarbonate to yield a polymerizable di- methacrylate monomer. The esterification and ion exchange processes were monitored via titrations and spectroscopy. This low viscosity (62 cP) di- functional modified ionomer is thermally homo-polymerized and co-polymerized with 55 wt% bis-GMA as a nonvolatile reactive diluent yielding impressive glass transition temperature (Tg) values up to 157 °C and 170 °C for homo- and co- polymer respectively as determined via differential scanning calorimetry method.

Behavior, synthesis, and effectiveness of an activity of anilinium-based Ionic Liquids (AnILs) as a hardeners and modifiers for epoxy-coatings of flax biocomposites

This paper presents a comprehensive investigation of the synthesis and properties of anilinium-based ionic liquids (AnILs) incorporating dicyanamide [DCA] and trifluoromethanesulfonate [OTf] anions. This study systematically examines the thermal behavior of these AnILs, highlighting the influence of cation size on distinct thermal transitions. Crucially, detailed thermal analyses were conducted for both AnILs and their corresponding epoxy resin systems. AnILs featuring [DCA] anion exhibited lower enthalpy values, indicative of a gradual polymerization process with potential energy inefficiency. In contrast, AnILs with [OTf] anion displayed elevated enthalpy values, signifying accelerated polymerization and significant potential for crosslinking. The resulting epoxy coatings were subjected to meticulous mechanical analyses. Notably, AnILs with a dicyanamide anion exhibited a noteworthy correlation between increased strength, enhanced crosslinking, and heightened structural complexity. Conversely, anilinium-based ionic liquids with [OTf] anion displayed distinctive polymerization behavior, even at lower temperatures. Investigation of the curing mechanics uncovered distinct polymerization pathways influenced by factors such as anion strength, dealkylation initiation temperature, and structural branching. Tensile strength assessments of coatings with trifluoromethanesulfonate anion revealed intriguing behavior, indicating that additional reinforcement during curing, is essential for maintaining structural integrity in impact-prone scenarios. Moreover, this study proposed a novel mechanism involving residual aniline molecules that influence structural outcomes. Overall, this research provides valuable insights into the intricate interplay of AnILs structures, polymerization dynamics, and mechanical properties, providing a foundational understanding for future advancements in functional coating applications.

Ionic liquid templated synthesis of cobalt‐substituted mesoporous aluminophosphates: A novel heterogeneous catalyst for selective oxidation of cyclohexane to cyclohexanol

AbstractOrdered hexagonal mesoporous aluminophosphate and its cobalt‐substituted analogue were successfully synthesized using ionic liquid as a structure‐directing agent. The resulting materials were systematically characterized by various analytical, spectroscopic, and imaging methods, confirming the presence of divalent cobalt in the tetrahedral framework of the matrix. Further, the high surface area, pore volume, and thicker mesopore walls of these materials impart good thermal and hydrothermal stability. The mesoporous catalysts showed excellent activity towards the oxidation of cyclohexane reactions using hydrogen peroxide as an oxidant, with 98.5 % conversion and 90.4 % selectivity towards cyclohexanol.

Coupling effect of ionic liquids on the mechanical, thermal, and chemical properties of polymer composites: A succinct review

AbstractThe growing study of polymer composites has motivated scientists to explore more methodologies to enhance the final demanding properties of polymer composites. Polymer composites have commonly been fabricated using thermosets or thermoplastics with synthetic or natural fillers. Lately, ionic liquids have been applied as coupling agents for polymer composites. In this succinct review, two types of ionic liquids, specifically imidazolium‐ and phosphonium‐based ionic liquids that are applied as coupling agents, are identified. Additionally, the synthesis of ionic liquids with different precursors and reactions is explained. The coupling effect of ionic liquids on the mechanical, thermal, and chemical properties of polymer composites is also succinctly reviewed. The knowledge shown in this review gives a more transparent comprehension of the fabrication of polymer composites coupled with ionic liquids and the essential properties of polymer composites. In conclusion, most imidazolium‐ and phosphonium‐based ionic liquids can improve several mechanical, thermal, and chemical properties of thermoset and thermoplastic composites.

Synthesis of imidazolium ionic liquid immobilized on magnetic mesoporous silica: A sorbent material in a green micro-solid phase extraction of multiclass pesticides in water

In this study, we synthesized an imidazolium ionic liquid immobilized on magnetic mesoporous silica (IL-MMS) and evaluated its performance as a sorbent material for a green micro-solid phase extraction (μ-SPE) of multiclass pesticides in water. The synthesized IL-MMS was characterized by various analytical techniques, including Fourier-transform infrared spectroscopy (FTIR), Brunauer–Emmett–Teller (BET) and Barrett–Joyner–Halenda (BJH) analyses (N2 adsorption/desorption), Vibrating Sample Magnetometer (VSM), energy-dispersive spectroscopy (EDS) and Field emission scanning electron microscopy (FESEM). Our synthesized IL-MMS demonstrated excellent magnetic properties (31.5 emu/g), high surface area (1177.4 m2/g), proper pore size (⁓4.2 nm) and volume (1.80 cm3/g). Under optimized extraction conditions, the IL-MMS exhibited a high adsorption capacity for a variety of pesticides, including organophosphates, carbamates, and pyrethroids. The proposed μ-SPE method using IL-MMS showed good linearity (R2 > 0.99), low limits of detection (LODs) ranging from 0.04 to 1.63 ng/L, and suitable recovery rate was between 82.4% and 109.8% for different pesticides. In addition, the method also exhibited excellent reproducibility, with relative standard deviations (RSDs) of less than 8% for both intra and inter-day precision. In overall, the synthesized IL-MMS has proven to be a highly promising material for sorbent-based micro-solid phase extraction (μ-SPE) of multiclass pesticides in water. With its simple, efficient, and eco-friendly approach to pesticide analysis, this method shows great potential for future pesticide detection and monitoring efforts due to its sensitivity, accuracy, and adaptability to various environmental conditions.

Synthesis and characterization of a novel ionic liquid for preconcentration of Brilliant Blue FCF (E 133) from some foods by ultrasound assisted temperature controlled ionic liquid dispersive liquid liquid microextraction method prior to spectrophotometric analysis; A comparative study

In this study, a novel ionic liquid (3-(3-chloro-2-hydroxypropyl)-1-butyl-1H-imidazol-3-ium hexafluorophosphate, (IL-2) was synthesized and characterized by FT-IR, NMR (1H,13C,31P) spectroscopy, and TGA. Two microextraction methods, ultrasonic assisted ionic liquid dispersive liquid liquid microextraction (USA-IL-DLLME) and ultrasonic assisted-temperature controlled ionic liquid DLLME, have been developed for preconcentration of Brilliant Blue FCF (E133) from some food products by the sythesized IL-2. For optimization of the both methods, several parameters such as volume of IL-2, pH, temperature, ultrasonication time, extraction time, centrifugation time, and salt effect were investigated. The obtained results for both methods under optimum conditions were compared. According to these results, the best limit of detection (4.55 µg L -1), enrichment factor (58), preconcentration factor (50), linear range (15–80 µg L -1), relative standard deviation % (1.15 %) were obtained by use of USA-TC-IL-DLLME method. Furthermore, the developed USA-TC-IL-DLLME method was succesfully applied to real samples for the preconcentration of Brilliant Blue FCF.

DABCO-PEG ionic liquid catalyzed synthesis, single-crystal structure, and antioxidant activity of a flavanone derivative

Globally, the occurrence of skin cancers has been increasing day by day due to unprotected skin and exposure to UV radiation. This research is focused toward the evaluation of the antioxidant potential of an OH-free flavanone derivative that was synthesized by using 1,4-diazabicyclo[2.2.2]octane–polyethylene glycol (DABCO-PEG) 400. Ionic liquid was prepared via the alkylation of DABCO using 1-pentyl bromide followed by mixing with PEG 400. The structure of the synthesized molecules was characterized through single-crystal XRD. The target flavanone, viz., 2-(4-isobutylphenyl)chroman-4-one, was subjected to free radical activity. In addition, in silico studies were carried out with proteins ribonucleotide reductase and tyrosinase and isobutyl containing flavanone, viz., 2-(4-isobutylphenyl)chroman-4-one. The flavanone 2-(4-isobutylphenyl)chroman-4-one showed significant inhibition at a concentration of 25 μg/ml compared to vitamin C, which was also supported by the molecular docking studies. The flavanones exhibit binding energies of −6.45 and −6.83 kcal/mol for ribonucleotide reductase and tyrosinase, respectively. The results were further validated by molecular dynamic simulations, which recommended that further investigation of this flavanone must be carried out before using it in potent drug discovery in the field of skin cancer.