Insights into the Properties and Potential Applications of Renewable Carbohydrate-Based Ionic Liquids: A Review

Nano silicated-FeAl2O4 functionalized by DL-alaninium nitrate ionic liquid (FeAl2O4-SiO2@[DL-Ala][NO3]) as versatile promotor for aqua-mediated synthesis of spiro[chromenopyrazole-indene-triones and spiro[chromenopyrazole-indoline-diones

In this work, the spinel FeAl2O4 was prepared and functionalized step-by-step with silica and alaninium nitrate ionic liquid ([DL-Ala][NO3]) to produce a bio-based multi-layered nanostructure (nano FeAl2O4-SiO2@[DL-Ala][NO3]). The obtained magnetized inorganic-bioorganic nanohybrid characterized by Fourier transform infrared spectroscopy (FT-IR), vibrating-sample magnetometry (VSM), field emission scanning electron microscopy (FESEM), energy-dispersive X-ray spectroscopy (EDAX), transmission electron microscopy (TEM), thermogravimetric analysis/differential scanning calorimetry (TGA/DSC), X-ray fluorescence (XRF), and X-Ray diffraction (XRD) analysis. A facile synthesis of some tricyclic dihydro-spiro[chromeno[2,3-c]pyrazole-4,2'-indene]triones and dihydro-spiro[chromeno[2,3-c]pyrazole-4,3'-indoline]diones via domino four-component one-pot reaction of various hydrazine derivatives, ethyl acetoacetate, heterocyclic 1,2-ketones (ninhydrin, isatin, 5-bromoisatin) and cyclic 1,3-diketones (dimedone and 1,3-cyclohexanedine), examined in the presence of nano FeAl2O4-SiO2@[DL-Ala][NO3] nanohybrid in refluxing aqueous media, successfully. The multi-aspect characteristics of the nanohybrid which consist of magnetized inorganic and bioorganic parts, could be the reason of its special catalytic efficacy. The recovery and reusability of the FeAl2O4-SiO2@[DL-Ala][NO3] magnetized nanoparticles (MNPs) were performed in two runs without significant activity loss.

Catalytic Transformation of Carbohydrates into Renewable Organic Chemicals by Revering the Principles of Green Chemistry

Adherence to the principles of green chemistry in a biorefinery setting ensures energy efficiency, reduces the consumption of materials, simplifies reactor design, and rationalizes the process parameters for synthesizing affordable organic chemicals of desired functional efficacy and ingrained sustainability. The green chemistry metrics facilitate assessing the relative merits and demerits of alternative synthetic pathways for the targeted product(s). This work elaborates on how green chemistry has emerged as a transformative framework and inspired innovations toward the catalytic conversion of biomass-derived carbohydrates into fuels, chemicals, and synthetic polymers. Specific discussions have been incorporated on the judicious selection of feedstock, reaction parameters, reagents (stoichiometric or catalytic), and other synthetic auxiliaries to obtain the targeted product(s) in desired selectivity and yield. The prospects of a carbohydrate-centric biorefinery have been emphasized and research avenues have been proposed to eliminate the remaining roadblocks. The analyses presented in this review will steer to developing superior synthetic strategies and processes for envisaging a sustainable bioeconomy centered on biomass-derived carbohydrates.

Rethinking the Esterquats: Synthesis, Stability, Ecotoxicity and Applications of Esterquats Incorporating Analogs of Betaine or Choline as the Cation in Their Structure

Esterquats constitute a unique group of quaternary ammonium salts (QASs) that contain an ester bond in the structure of the cation. Despite the numerous advantages of this class of compounds, only two mini-reviews discuss the subject of esterquats: the first one (2007) briefly summarizes their types, synthesis, and structural elements required for a beneficial environmental profile and only briefly covers their applications whereas the second one only reviews the stability of selected betaine-type esterquats in aqueous solutions. The rationale for writing this review is to critically reevaluate the relevant literature and provide others with a "state-of-the-art" snapshot of choline-type esterquats and betaine-type esterquats. Hence, the first part of this survey thoroughly summarizes the most important scientific reports demonstrating effective synthesis routes leading to the formation of both types of esterquats. In the second section, the susceptibility of esterquats to hydrolysis is explained, and the influence of various factors, such as the pH, the degree of salinity, or the temperature of the solution, was subjected to thorough analysis that includes quantitative components. The next two sections refer to various aspects associated with the ecotoxicity of esterquats. Consequently, their biodegradation and toxic effects on microorganisms are extensively analyzed as crucial factors that can affect their commercialization. Then, the reported applications of esterquats are briefly discussed, including the functionalization of macromolecules, such as cotton fabric as well as their successful utilization on a commercial scale. The last section demonstrates the most essential conclusions and reported drawbacks that allow us to elucidate future recommendations regarding the development of these promising chemicals.

Excellence in Acrylation - Scope and Limitation of Glucosyl Imidazolium-coated Novozym 435 Catalyzed (Meth)acryl Ester Synthesis

The incorporation of carbohydrate based ionic liquids as a support for Novozym 435 was previously studied by the authors for the acrylation of n-butanol as the target substrate, which was used as the foundation for the design of experiments. The combination of carbohydrate based ionic liquids and Novozym 435 remains a key aspect of this work. Building upon this, the reaction parameters were optimized for the Novozym catalyst. Substrate screening was performed to explore the scope and limitations of room temperature acrylation reactions. Herein, different alcohols and reaction conditions were screened extensively for the different acrylate products with yields of up to 99.9 % determined via gas chromatography (GC). Standard straight chain alcohols, 2-functionalized ethanol derivatives with electron donating and withdrawing groups, and more sterically challenging substrates were investigated over a broad concentration region. To further underline the applicability of the modified biocatalyst, two alcohols were converted with methacrylic acid. The presented method offers a greener pathway for acrylate synthesis, which eliminates the need for high reaction temperatures, strongly acidic catalysts and/or polymerization inhibitors as used in non-biocatalytic acrylate synthesis.

Upcycling of Poly(lactic acid) Waste: A Valuable Strategy to Obtain Ionic Liquids

With the aim to investigate new strategies for upcycling of plastic waste, we performed aminolysis of poly(lactic acid) (PLA), using N,N-dimethylethylenediamine (DMEDA), N,N-dimethylpropylenediamine (DMPDA), and 3-aminopropylimidazole (API) as nucleophiles. The N-substituted lactamides obtained were alkylated by using alkyl halides differing in alkyl chain length, obtaining organic salts that in most cases behaved as ionic liquids (ILs). Both aminolysis of PLA and alkylation of amides were carried out taking into consideration the basic principles of the holistic approach to green chemistry, applied at a laboratory scale, and carefully selecting the nature of the reaction solvent, temperature range, and amount of reagents. Organic salts obtained from the alkylation of N-substituted lactamides were investigated to determine their glass or solid-liquid transitions and their thermal stability. Furthermore, cytotoxicity toward normal lung fibroblasts was also assessed. Data collected show that the proposed strategy represents a valuable protocol to upcycle plastic waste, using it as starting material to obtain alternative solvents of potential industrial relevance.

A comprehensive study demonstrating the influence of the solvent composition on the phytotoxicity of compounds, as exemplified by 2,4-D-based ILs with a choline-type cation

BACKGROUND

Growing concern for the protection of the environment and existing ecosystems has resulted in increasing consideration of phytotoxicity tests as valid ecotoxicological indicators of the potential hazards of the use of ionic liquids (ILs) or any other chemical. The objective of this study was to gain a detailed understanding of the influence of the solvent composition of spray solutions on the phytotoxic effect of foliar application of ionic pairs with weak (choline 2,4-dichlorophenoxyacetate, [Chol][2,4-D]), medium (N-hexylcholine 2,4-dichlorophenoxyacetate, [C6 Chol][2,4-D]) and good (N-dodecylcholine 2,4-dichlorophenoxyacetate, [C12 Chol][2,4-D]) surface-active properties.

RESULTS

Experimental results unambiguously demonstrated that the biological activity of the test salt solutions, particularly [Chol][2,4-D] and [C6 Chol][2,4-D], can be strongly affected by the addition of an organic solvent, such as methanol, ethanol, dimethylformamide (DMF) or dimethylsulfoxide (DMSO) compared to solutions in pure water. However, the observed tendency is less pronounced for the compound exhibiting good surface activity, [C12 Chol][2,4-D].

CONCLUSIONS

The collected findings show that caution is warranted in the exploitation or modification of methodologies for assessing phytotoxicity to ensure the reliable interpretation of obtained results for environmental risk assessment or building quantitative structure-activity relationship (QSAR) models. © 2023 Society of Chemical Industry.

Novel Glucosylimidazolium Ionic-Liquid-Supported Novozym 435 Catalysts - A Proof of Concept for an Acrylation Reaction

A series of novel ionic liquids based on glucose was synthesized in high yields in simple two or three-step reaction procedures. These carbohydrate-based ionic liquids were studied and compared to commercially available imidazolium-based ionic liquids as supports for Novozym 435 in the acrylation of n-butanol. A direct correlation between the availability of hydroxy groups and the overall activity as well as an enhanced recyclability of the biocatalyst has been found for the glucose-based ionic liquids.

Fabrication and Model Characterization of the Electrical Conductivity of PVA/PPy/rGO Nanocomposite

Owing to the numerous advantages of graphene-based polymer nanocomposite, this study is focused on the fabrication of the hybrid of polyvinyl alcohol (PVA), polypyrrole (PPy), and reduced graphene-oxide. The study primarily carried out the experimentation and the mathematical analysis of the electrical conductivity of PVA/PPy/rGO nanocomposite. The preparation method involves solvent/drying blending method. Scanning electron microscopy was used to observe the morphology of the nanocomposite. The electrical conductivity of the fabricated PVA/PPy/rGO nanocomposite was investigated by varying the content of PPy/rGO on PVA. From the result obtained, it was observed that at about 0.4 (wt%) of the filler content, the nanocomposite experienced continuous conduction. In addition, Ondracek, Dalmas s-shape, dose–response, and Gaussian fitting models were engaged for the analysis of the electrical transport property of the nanocomposite. The models were validated by comparing their predictions with the experimental measurements. The results obtained showed consistency with the experimental data. Moreover, this study confirmed that the electrical conductivity of polymer-composite largely depends on the weight fraction of fillers. By considering the flexibility, simplicity, and versatility of the studied models, this study suggests their deployment for the optimal characterization/simulation tools for the prediction of the electrical conductivity of polymer-composites.

Ultrastable Conjugated Microporous Polymers Containing Benzobisthiadiazole and Pyrene Building Blocks for Energy Storage Applications

In recent years, conjugated microporous polymers (CMPs) have become important precursors for environmental and energy applications, compared with inorganic electrode materials, due to their ease of preparation, facile charge storage process, π-conjugated structures, relatively high thermal and chemical stability, abundance in nature, and high surface areas. Therefore, in this study, we designed and prepared new benzobisthiadiazole (BBT)-linked CMPs (BBT-CMPs) using a simple Sonogashira couplings reaction by reaction of 4,8-dibromobenzo(1,2-c;4,5-c')bis(1,2,5)thiadiazole (BBT-Br2) with ethynyl derivatives of triphenylamine (TPA-T), pyrene (Py-T), and tetraphenylethene (TPE-T), respectively, to afford TPA-BBT-CMP, Py-BBT-CMP, and TPE-BBT-CMP. The chemical structure and properties of BBT-CMPs such as surface areas, pore size, surface morphologies, and thermal stability using different measurements were discussed in detail. Among the studied BBT-CMPs, we revealed that TPE-BBT-CMP displayed high degradation temperature, up to 340 °C, with high char yield and regular, aggregated sphere based on thermogravimetric analysis (TGA) and scanning electron microscopy (SEM), respectively. Furthermore, the Py-BBT-CMP as organic electrode showed an outstanding specific capacitance of 228 F g-1 and superior capacitance stability of 93.2% (over 2000 cycles). Based on theoretical results, an important role of BBT-CMPs, due to their electronic structure, was revealed to be enhancing the charge storage. Furthermore, all three CMP polymers featured a high conjugation system, leading to improved electron conduction and small bandgaps.

Antimicrobial, Cytotoxic and Mutagenic Activity of Gemini QAS Derivatives of 1,4:3,6-Dianhydro-l-iditol

A series of quaternary diammonium salts derivatives of 1,4:3,6-dianhydro-l-iditol were synthesized, using isommanide (1,4:3,6-dianhydro-d-mannitol) as a starting material. Both aromatic (pyridine, 4-(N,N-dimethylamino)pyridine (DMAP), (3-carboxamide)pyridine; N-methylimidazole) and aliphatic (trimethylamine, N,N-dimethylhexylamine, N,N-dimethyloctylamine, N,N-dimethyldecylamine) amines were used, giving eight gemini quaternary ammonium salts (QAS). All salts were tested for their antimicrobial activity against yeasts, Candida albicans and Candida glabrata, as well as bacterial Staphylococcus aureus and Escherichia coli reference strains. Moreover, antibacterial activity against 20 isolates of S. aureus collected from patients with skin and soft tissue infections (n = 8) and strains derived from subclinical bovine mastitis milk samples (n = 12) were evaluated. Two QAS with octyl and decyl residues exhibited antimicrobial activity, whereas those with two decyl residues proved to be the most active against the tested pathogens, with MIC of 16-32, 32, and 8 µg/mL for yeast, E. coli, and S. aureus reference and clinical strains, respectively. Only QAS with decyl residues proved to be cytotoxic in MTT assay against human keratinocytes (HaCaT), IC₅₀ 12.8 ± 1.2 μg/mL. Ames test was used to assess the mutagenic potential of QAS, and none of them showed mutagenic activity in the concentration range 4-2000 µg/plate.

n-Butane, iso-Butane and 1-Butene Adsorption on Imidazolium-Based Ionic Liquids Studied with Molecular Beam Techniques

The interaction of molecules, especially hydrocarbons, at the gas/ionic liquid (IL) surface plays a crucial role in supported IL catalysis. The dynamics of this process is investigated by measuring the trapping probabilities of n-butane, iso-butane and 1-butene on a set of frozen 1-alkyl-3-methylimidazolium-based ILs [Cn C1 Im]X, where n=4, 8 and X- =Cl- , Br- , [PF6 ]- and [Tf2 N]- . The decrease of the initial trapping probability with increasing surface temperature is used to determine the desorption energy of the hydrocarbons at the IL surfaces. It increases with increasing alkyl chain length n and decreasing anion size for the ILs studied. We attribute these effects to different degrees of alkyl chain surface enrichment, while interactions between the adsorbate and the anion do not play a significant role. The adsorption energy also depends on the adsorbing molecule: It decreases in the order n-butane>1-butene>iso-butane, which can be explained by different dispersion interactions.

Ecotoxicity interspecies study of ionic liquids based on phosphonium and ammonium cations

This work studies the effects of different bromide-based ionic liquids, with phosphonium and ammonium cations, towards several environmental biomodels: Daphnia magna, Allivibrio fischeri, Raphidocelis subcapitata. Results indicate that toxicity clearly depends on the biomodel, Allivibrio fischeri being the least sensitive one while Daphnia magna is more severely affected in the presence of the studied ionic liquids. In most of the cases, phosphonium moieties are less toxic than ammonium ionic liquids. Furthermore, a prediction about the oral toxicity and carcinogenicity of the studied ionic liquids has been also carried out, showing that these chemical structures may suggest significant toxicity but not present genotoxic or nongenotoxic carcinogenicity.

Conformation of poly(ethylene glycol) in aqueous cholinium amino acid hybrid solvents

HYPOTHESIS

Hybrid solvents based on cholinium amino acid ionic liquids ([Ch][AA] ILs) mixed with water are environmentally benign solvents with low toxicity. [Ch][AA] ILs are used in biomass pretreatment processes to dissolve targeted (macro)molecules such as lignin from lingnocellulose. Understanding how [Ch][AA] ILs dissolve polymers is therefore of great interest for the rational design of ILs towards industrial application. Variation of the IL anion and the water concentration are hypothesised to change the solvent properties of [Ch][AA] hybrid solvents. Therefore, we probe the solvent quality of [Ch][AA] aqueous solutions with different anions (glycinate, prolinate and argininate) and water concentration for the simple model solute poly(ethylene glycol) (PEG).

EXPERIMENTS

Partial phase diagrams were produced to probe the salting-out effect of [Ch][AA] ILs towards PEG (M_w = 38 kDa). Small-angle neutron scattering experiments of deuterated PEG in hydrogenous [Ch][AA] aqueous solutions were performed to determine the polymer radius of gyration at infinite dilution (R_g,0) via Zimm-plots. Polymer concentration dependent apparent R_g values were obtained fitting an excluded volume polymer model onto the scattering data. Blends of hydrogenous and deuterated PEG under zero average contrast conditions were analysed to probe R_g at high polymer concentrations.

FINDINGS

Hydrogen bond capacity of the anion is key to the salting-out effect of [Ch][AA] ILs on PEG. R_g,0 depends on anion species and water concentration. At IL:water = 1:30 (mole:mole) and 37 °C, cholinium argininate and cholinium glycinate are close to theta solvents while cholinium prolinate and dilute cholinium argininate (IL:water = 1:100) are between theta and good solvents.

Toward the Proactive Design of Sustainable Chemicals: Ionic Liquids as a Prime Example

The tailorable and often unique properties of ionic liquids (ILs) drive their implementation into a broad variety of seminal technologies. The modular design of ILs allows in this context a proactive selection of structures that favor environmental sustainability─ideally without compromising their technological performance. To achieve this objective, the whole life cycle must be taken into account and various aspects considered simultaneously. In this review, we discuss how the structural design of ILs affects their environmental impacts throughout all stages of their life cycles and scrutinize the available data in order to point out knowledge gaps that need further research activities. The design of more sustainable ILs starts with the selection of the most beneficial precursors and synthesis routes, takes their technical properties and application specific performance into due account, and considers its environmental fate particularly in terms of their (eco)toxicity, biotic and abiotic degradability, mobility, and bioaccumulation potential. Special emphasis is placed on reported structure-activity relationships and suggested mechanisms on a molecular level that might rationalize the empirically found design criteria.

Bioderived Ionic Liquids and Salts with Various Cyano Anions as Precursors for Doped Carbon Materials

Carbohydrate moieties were combined with various cross-linkable anions (thiocyanate [SCN], tetracyanoborate [TCB], tricyanomethanide [TCM], and dicyanamide [DCA]) and investigated as precursors for the synthesis of nitrogen-doped and nitrogen-/sulfur-co-doped carbons. The influence of the molecular structures of the precursors on their thermophysical properties and the properties of the derived carbon materials was elucidated and compared to petroleum-derived analogs. A carbohydrate-based ionic liquid featuring an [SCN] anion yielded more carbon residues upon carbonization than its 1-ethyl-3-methylimidazolium analog, and the resulting dual-doping of the derived carbon material translated to enhanced catalytic activity in the oxygen reduction reaction.

Effects of ionic liquid [N4444] AOT on rice seedling growth cytomembrane damage and rhizobacteria resistance

Ionic liquids (ILs) are solvents composed of ions, containing a large asymmetric cation with an anion. With increasing and widespread applications, the toxic effects of ILs have been considerable in recent years. This study explained the effects of the new functional ionic liquids [N₄₄₄₄] bis(2-ethylhexyl) sulfonyl succinate (AOT) on rice seedling and the growth of rhizobacteria. The rice seeds pretreated by [N₄₄₄₄] AOT revealed that it exhibited a significant negative impact on rice seedlings. The inhibition of rice growth increased with increasing concentration. When the concentration of [N₄₄₄₄] AOT increased to 0.25 and 0.5 mL L^-1, the germination potential decreased by 40.0% and 86.3%, respectively, compared with the control. The germination potential and germination rate of rice were reduced, and the stress effect of ionic liquid on the root parts was higher than the aerial parts. The biomass of rice seedlings was decreased by 34.8 to 91.2%. Iodinic propane staining showed that by increasing concentration, the root cell cytomembrane damage level was increased and also changed the cell shapes, especially under 0.25 mg L^-1 concentration stress. However, rhizobacteria of rice showed strong [N₄₄₄₄] AOT-resistant characteristics when the concentration was reached to 120 mg L^-1. The ILs even more promoted the growth of Enterobacter sp. NP1142 and Pantoea sp. BR23. It was indicated that IL [N₄₄₄₄] AOT can be degraded easily by rhizobacteria to eliminate the eco-risk of ILs.

Heterogeneous Catalysis with the Participation of Ionic Liquids

This mini-review briefly describes the recent progress in the design and development of catalysts based on the presence of ionic liquids. In particular, the focus was on heterogeneous systems (supported ionic liquid (IL) phase catalysts (SILPC), solid catalysts with ILs (SCILL), porous liquids), which due to the low amounts of ionic liquids needed for their production, eliminate basic problems observed in the case of the employment of ionic liquids in homogeneous systems, such as high price, high viscosity, and efficient isolation from post-reaction mixtures.