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Since the 21st century, transparent flexible sensors (TFSs) have been widely employed in abundant fields, such as smart glasses, intelligent watches, robots, electronic skin, especially biomedicine. Presently, various materials have been developed, such as metal‐based, carbon‐based, conductive polymer‐based, and ionic liquid‐based (IL‐based) materials. Compared with the first three materials, IL, as a novel material, with the tendency of green chemistry development, has a high application prospect in TFSs. Based on this, this paper mainly discusses recent advances in TFSs based on ILs, with special emphasis on the role of ILs and the factors influencing transparency as well as electricity. The current challenges and opportunities for each type of sensors based on IL are also studied. [ABSTRACT FROM AUTHOR]

Significant progress has been made in the past decades in the capture, storage, and utilization of greenhouse gases, particularly CO2. In general, the synthesis of most of the available CO2 sorbents is not ecofriendly and can require multistep synthesis in order to prepare and/or activate, which is considered a strict violation of green chemistry principles (GCPs). Therefore, thinking of green frameworks to design chemical products and processes becomes essential to mitigate these challenges. This paper provides an in‐depth review of available green sorbents for CO2 capture with an emphasis on those prepared from biorenewable materials and ionic liquids. A new metric is presented to classify these sorbents based on their degree of compliance to the GCPs, which could be a useful tool in selection of green alternatives. Due to the interdisciplinary nature of this research topic, a wide range of literature is available in multiple areas including but not limited to chemistry and engineering. Hence, this review targets a wide range of scientists including chemists, biotechnologists, material scientists, and meteorologists, as well as green industrial corporations. [ABSTRACT FROM AUTHOR]

Natural auxins are a group of plant hormones that affect plant growth and development. The most common auxin is indole‐3‐acetic acid (IAA), which is mainly synthesized from tryptophan. Since converting synthetic auxins into an ionic liquid increases their herbicidal activity, an attempt was made to synthesize new amino acid ionic liquids (AAILs) with l‐tryptophanate anions. As a result of the synthesis, two homologous series, tetraalkylammonium l‐tryptophanates and dialkyldimethylammonium l‐tryptophanates, were obtained with yields exceeding 95 %. For the obtained AAILs, basic physicochemical properties (solubility in solvents of different polarity, thermal stability, phase changes, and surface activity) were determined, and whether the obtained salts act as growth stimulants for lettuce (Lactuca sativa L.) was evaluated. The transformation of l‐tryptophan into AAILs improved the physicochemical properties and increased the auxin activity. In addition, the higher content of nutrients (micro‐ and macroelements) made lettuce a healthier food product. [ABSTRACT FROM AUTHOR]

BACKGROUND Due to environmental concerns, there is a need to eliminate or drastically reduce the use of conventional organic solvents, as these are environmentally harmful. This paper reports on a novel one-pot synthesis of tetrabromoethylcyclohexane ( TBECH) in aqueous medium, using amino-functionalized ionic liquids, which catalyze the reaction and make it more environmentally friendly. RESULTS Compared with the traditional synthesis, tetrabromoethylcyclohexane is obtained with equivalent yield (90%), at room temperature, in a short reaction time (∼2 h compared with the previous 17 h) and with a strong reduction of the use of organic solvents; finally two isomers are obtained instead of four. Furthermore, a novel procedure to prepare the ionic liquids has been designed and two new ones have also been synthesised. The calculated environmental factors ( EFs), which measure the environmental sustainability, showed a strong reduction of the use of organic solvents for all syntheses of ionic liquids and TBECHs. CONCLUSIONS The excellent properties of amino-functionalized ionic liquids as solvents and catalysts for chemo- and diastereo-selective bromination of C  C bonds in water were confirmed with the synthesis of tetrabromoethylcyclohexane. Given the wide use of brominated compounds in the chemical industry, this procedure could be of wide interest. © 2015 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Sustainable ionic liquids are promising compounds in green chemistry applications. While using them as solvent or reaction media is an important step towards more environmentally friendly chemistry, their synthesis is usually expensive and not green at all. Herein, a benign route to synthesize task ‐ specific ionic liquids is presented, offering several possible functionalities in the cation and anion (artwork by D. Kraban). More information can be found in the Full Paper by C. Liedel et al. on page 11810. [ABSTRACT FROM AUTHOR]

Deep eutectic solvents (DESs) are formed by mixing quaternary ammonium salts (e.g., choline chloride) and hydrogen-bond donors (e.g., glycerol or urea), which leads to biodegradable and readily available ionic solvents at room temperature. Analogous to other ionic liquids, DESs represent a promising reaction media if hydrophobic and hydrophilic substrates need to be combined. This paper assesses DESs as reaction media for chymotrypsin-catalyzed peptide synthesis. After careful determination of the reaction conditions (e.g., water content, enzyme loading), α-chymotrypsin displayed high activity for peptide synthesis in choline chloride/glycerol mixtures to afford productivities of ca. 20 g L-1 h-1 and with complete selectivity for the peptide, which is in contrast to the detrimental hydrolysis pathway observed in aqueous media. The nonimmobilized suspended enzyme could be reused several times by simple filtration with excellent to moderate activities. Overall, the results reported suggest that choline chloride based DESs may become promising neoteric solvents for peptide synthesis through biocatalysis. [ABSTRACT FROM AUTHOR]

There will be common challenges to scaling‐up any ionic liquids separations technologies which require very large volumes of ionic liquid. Some of these challenges are illustrated in this personal account which chronicles the extraction of chitin from shrimp shell from discovery to current commercialization efforts. The road being taken from discovery in an academic laboratory, through attempts to navigate the scaling‐up to commercial scale using the vehicle of a faculty startup company is rewarding, but fraught with roadblocks, detours, and unexpected challenges. The differences in 'technically feasible' and 'commercially viable' are not always evident from the beginning of the journey, however, one wonders what achievements we miss as a Society because it was assumed to not be commercially viable. [ABSTRACT FROM AUTHOR]

We report the synthesis of task-specific imidazolium ionic compounds and ionic liquids with key functionalities of organic molecules from electro-, polymer-, and coordination chemistry. Such products are highly functional and potentially suitable for technology applications even though they are formed without elaborate reactions and from cheap and potentially green reagents. We further demonstrate the versatility of the used synthetic approach by introducing different functional and green counterions to the formed ionic liquids directly during the synthesis or after metathesis reactions. The influence of different cation structures and different anions on the thermal and electrochemical properties of the resulting ionic liquids is discussed. Our goal is to make progress towards economically competitive and sustainable task-specific ionic liquids. [ABSTRACT FROM AUTHOR]

Ionic liquids (ILs) and deep eutectic solvents (DESs) are designable solvents having widespread applications. They have gained tremendous attention in the last few decades due to their inherent physicochemical properties, making them distinctive solvents from technological point of view. There are a large number of research articles published on physicochemical properties and applications of ILs and DESs, however, limited research work is available on the phytotoxic effect of ILs and DESs. They are considered as environmentally friendly greener solvents, however, during experimental work, it has been found that they are not always as green as desired. It has been reported that ILs and DESs have phytotoxic properties and effect both aquatic and terrestrial plants. Here the phototoxic problems of ILs and DESs are reviewed. Similar to the traditional solvents, the aforementioned solvents are not safe, and it is important to determine their phytotoxicity prior to highlighting their potential applications. This review will help researchers to design new eco‐friendly ILs and DESs, which can fulfil the twelve principles of green chemistry. [ABSTRACT FROM AUTHOR]

Ionic liquids (ILs) and deep eutectic solvents (DESs) debuted with a promise of a superior sustainability footprint due to their low vapor pressure. However, their toxicity and high cost compromise this footprint, impeding their real‐world applications. Fortunately, their property tunability through a rational selection of precursors, including bioderived ones, provides a strategy to ameliorate toxicity, lower cost, and endow new functions. This Review discusses whether ILs and DESs are sustainable solvents and how they contribute to sustainable chemical processes. [ABSTRACT FROM AUTHOR]

5‐Hydroxymethylfurfural (HMF) is identified as an important bio‐based platform chemical to bridge petroleum‐based and biomass‐based resources. It can be obtained through dehydration of various carbohydrates as well as converted to value‐added fuels and chemicals. As designer solvents, ionic liquids (ILs) and deep eutectic solvents (DESs) have been widely used in catalytic transformation of biomass derivatives to various chemicals. This Review summarizes recent progress in experimental and theoretical studies on dehydration of carbohydrates such as fructose, glucose, sucrose, cellobiose, chitosan, cellulose, inulin, and even raw biomass to generate HMF using ILs and DESs as catalysts/cocatalysts and/or solvents/cosolvents. It also gives an overview of IL and DES‐involved catalytic transformation of HMF to downstream products via oxidation, reduction, esterification, decarboxylation, and so forth. Challenges and prospects of ILs and DESs are also proposed for further production of HMF and HMF derivatives from biomass in green and sustainable processes. [ABSTRACT FROM AUTHOR]

Pyrimidines and their hybrid molecules have continued to be a favorable area for organic chemists owing to their richness in natural and synthetic compounds with multifarious involvement in pharmaceuticals and polymers and act as ligands. Different novel and greener synthetic protocols were developed in the last decades, but microwave‐assisted synthetic protocols played a significant role in constructing pyrimidine and its derivatives. In this article, we summarized the microwave‐supported strategy for the construction of pyrimidine fused or linked/tethered with other heterocycles, polysubstituted pyrimidines, solid‐supported synthesis of pyrimidines, and ionic liquid‐catalyzed strategies for the synthesis of pyrimidine and its derivatives reported in the last decade. Solid‐supported protocols using resins and ionic liquid‐catalyzed strategies afforded the corresponding products with excellent yield by dual activation. In most of the reports, the microwave‐irradiated approach was compared with conventional/traditional heating and found better in terms of reaction time, yield, atom economy, adherence with green chemistry principles, and reduction in purification wastage. Various authors evaluated the in vitro potential of synthesized pyrimidine derivatives for antimicrobial and antimalarial potential, and found moderate to excellent biological activity. [ABSTRACT FROM AUTHOR]

Adaptation of all‐in‐one ionic systems with ionic liquids (ILs) serving as solvent, reactant, and catalyst is an innovative approach in the organic synthesis. Mild and bio clean choline based ILs as all‐in‐one systems (solvent, reagent, and catalyst) were developed via a simple metathesis approach and were applied on the ring‐opening reaction of epoxides. Sustained transformation of various epoxides using choline cyanide, azide, and hydroxide ILs delivered a neat, efficient and convenient protocol for the synthesis of β‐substituted alcohols in moderate to high yields (64‐97 %) with excellent activity and selectivity as confirmed by nuclear magnetic resonance (NMR) spectroscopic data. [ABSTRACT FROM AUTHOR]

Cover Feature: Enhancing the Antioxidant Activity of Technical Lignins by Combining Solvent Fractionation and Ionic-Liquid Treatment (ChemSusChem 21/2019) B The Cover Feature b shows a cascade biorefinery process for the upgrading of technical lignins and sustainable production of phenolic oligomers of interest as substitutes for commercial antioxidants. A grass soda technical lignin undergoes a process combining solvent fractionation and treatment with an ionic liquid, and a comprehensive investigation of the structural modifications is performed. [Extracted from the article]

Asymmetric organocatalysis is becoming one of the main tools for the synthesis of chiral compounds that are needed as medicines, crop protection agents, and other bioactive molecules. It can be effectively combined with various green chemistry methodologies. Intensification techniques, such as ball milling, flow, high pressure, or light, bring not only higher yields, faster reactions, and easier product isolation, but also new reactivities. More sustainable reaction media, such as ionic liquids, deep eutectic solvents, green solvent alternatives, and water, also considerably enhance the sustainability profile of many organocatalytic reactions. [ABSTRACT FROM AUTHOR]

Acid‐catalysed conversion of biomass, specifically cellulose, holds promise to create value‐added, renewable replacements for many petrochemical products. We investigated an unusual acid‐catalysed transformation of cellulose and cellobiose in the biphasic solvent system zinc chloride hydrate (ionic liquid)/anisole. Here, furyl hydroxymethyl ketone and furfural are obtained as major products, which are valuable but less commonly formed in high yields in transformations of cellulosic substrates. We explored this chemistry in small‐scale model reactions and applied the optimised methods to the conversion of cellulose in bench‐scale processes. The optimum reaction system and preferred reaction conditions are defined to select for highly desirable furanoid products in the highest known yields (up to 46 %) directly from cellulose or cellobiose. The method avoids the use of added catalysts: the ionic solvent zinc chloride hydrate possesses the intrinsic acidity required for the hydrolysis and chemical transformation steps. The process involves inexpensive media for the catalytic conversion of cellulose into high‐value products under mild processing conditions. [ABSTRACT FROM AUTHOR]

The use of safe and sustainable solvents able to solvate reagents and to catalyze their reactions at temperatures below 100 °C is an innovative strategy to develop future lignocellulosic biorefineries. Many low‐transition‐temperature mixtures (LTTMs) have been investigated for this purpose. Among them, natural deep eutectic solvents (NADESs) have been proposed as cheap and renewable alternatives to ionic liquids for the synthesis of bio‐based chemical building blocks. We compare herein the ability of several organic acids/choline chloride/water LTTMs to perform D‐fructose dehydration to 5‐hydroxymethylfurfural (5‐HMF). The addition of chloride salts as well as an increased proportion of choline chloride promotes 5‐HMF formation, which seems to indicate a beneficial effect of chloride anions on D‐fructose dehydration. Besides improving selectivity by at least 10 %, increasing the choline chloride/acid ratio could enhance the biodegradability of the LTTMs. Unlike other acidic components, maleic and citric acids are especially selective at early D‐fructose conversion. Maleic acid was the most selective acidic component among the tested chemicals, achieving an 80 % 5‐HMF molar yield in 1 h at 90 °C. It's in the mix: Mixtures of organic acids and choline chloride can catalyze the dehydration of D‐fructose to 5‐hydroxymethylfurfural. The ratio between the mixture components can be used to optimize selectivity. The amount of water in the mixture is also crucial and impacts the temperature required for the dehydration reaction. [ABSTRACT FROM AUTHOR]

The nanostructure of a series of choline chloride/urea/water deep eutectic solvent mixtures was characterized across a wide hydration range by neutron total scattering and empirical potential structure refinement (EPSR). As the structure is significantly altered, even at low hydration levels, reporting the DES water content is important. However, the DES nanostructure is retained to a remarkably high level of water (ca. 42 wt % H2O) because of solvophobic sequestration of water into nanostructured domains around cholinium cations. At 51 wt %/83 mol % H2O, this segregation becomes unfavorable, and the DES structure is disrupted; instead, water–water and DES–water interactions dominate. At and above this hydration level, the DES–water mixture is best described as an aqueous solution of DES components. [ABSTRACT FROM AUTHOR]

New conjugated materials, based on the triphenylamine- thiophene moiety and integrating azomethine bonds with a dibenzofuran unit or a cyanovinyl bond with a phenylthiophene or bithiophene unit, have been synthesized by using a wide range of green reactions such as direct heteroarylation coupling reactions, Knoevenagel and Schiff-base condensations and Stille cross-coupling reactions using ionic-liquid-supported thiophenylstannane. The electronic properties of the new molecules were analyzed by UV/Vis spectroscopy and cyclic voltammetry. The potential use of the molecules as donor materials for photovoltaic conversion were evaluated in simple bilayer solar cells using C60 as the acceptor material. [ABSTRACT FROM AUTHOR]

Ionic liquids can both act as a solvent and mediate esterification to valorize low-titer volatile fatty acids and generate organic solvents from renewable carbon sources including biowaste and CO2. In this study, four phosphonium ionic liquids were tested for single-stage extraction of acetic acid from a dilute stream and esterification to ethyl acetate with added ethanol and heat. The esterification proceeded with a maximum conversion of 85.9±1.3 % after 30 min at 75 °C at a 1:1 stoichiometric ratio of reactants. Extraction and esterification can be tailored using mixed-anion ionic liquids; this is demonstrated herein using a common trihexyl(tetradecyl)phosphonium cation and a mixed chloride and bis(trifluoromethylsulfonyl)imide anion ionic liquid. As a further proof-of-concept, ethyl acetate was generated from an ionic liquid-driven esterification of an acetic acid extractant generated using CO2 as the only carbon source by microbial electrosynthesis. [ABSTRACT FROM AUTHOR]

Nanometer-sized metal particles constitute an unavoidable family of catalysts, combining the advantages of molecular complexes in regards to their catalytic performances and the ones of heterogeneous systems in terms of easy recycling. As part of this research, our group aims at designing well-defined metal nanoparticles based-catalysts, in non-conventional media (ionic liquids or water), for various catalytic applications (hydrogenation, dehalogenation, carbon-carbon coupling, asymmetric catalysis) in mild reaction conditions. In the drive towards a more eco-responsible chemistry, the main focuses rely on the search of highly active and selective nanocatalysts, in association with an efficient recycling mainly under pure biphasic liquid-liquid conditions. In this Personal Account, we proposed our almost fifteen-years odyssey in the world of metal nanoparticles for a sustainable catalysis. [ABSTRACT FROM AUTHOR]

Developing new green solvents in designing chemical products and processes or successfully employing the already existing ones is one of the key subjects in green chemistry and is especially important in organometallic chemistry, which is an interdisciplinary field. Can we advantageously also use unconventional reaction media in place of current harsh organic solvents for polar organometallic compounds? This microreview critically analyses the state of the art with regard to this topic and showcases recent developments and breakthroughs that are becoming new research directions in this field. Because metals cover a vast swath of the Periodic Table the content is organised into three sections discussing the reactivity of organometallic compounds of s-, p- and d-block elements in unconventional solvents. [ABSTRACT FROM AUTHOR]

Data on various specific aspects of the synthesis of polymeric materials under microwave irradiation and on the use of such specific class of solvents as ionic liquids as the reaction medium, are analyzed in this review. Chemistry and chemical technology should be considered as a powerful means to achieve sustainable development goals, so the characteristics of microwave-induced processes and processes using ionic liquids have been discussed in relation to the 12 principles of green chemistry. These processes are shown to possess high resource efficiency and energy efficiency potential. Copyright © 2015 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

In recent years, the microwave-assisted ionic-liquid method has been accepted as a promising methodology for the preparation of nanomaterials and cellulose-based nanocomposites. Applications of this method in the preparation of cellulose-based nanocomposites comply with the major principles of green chemistry, that is, they use an environmentally friendly method in environmentally preferable solvents to make use of renewable materials. This minireview focuses on the recent development of the synthesis of nanomaterials and cellulose-based nanocomposites by means of the microwave-assisted ionic-liquid method. We first discuss the preparation of nanomaterials including noble metals, metal oxides, complex metal oxides, metal sulfides, and other nanomaterials by means of this method. Then we provide an overview of the synthesis of cellulose-based nanocomposites by using this method. The emphasis is on the synthesis, microstructure, and properties of nanostructured materials obtained through this methodology. Our recent research on nanomaterials and cellulose- based nanocomposites by this rapid method is summarized. In addition, the formation mechanisms involved in the microwave-assisted ionic-liquid synthesis of nanostructured materials are discussed briefly. Finally, the future perspectives of this methodology in the synthesis of nanostructured materials are proposed. [ABSTRACT FROM AUTHOR]

Rapid progress in the field of ionic liquids in recent decades led to the development of many outstanding energy-conversion processes, catalytic systems, synthetic procedures, and important practical applications. Task-specific optimization emerged as a sharpening stone for the fine-tuning of structure of ionic liquids, which resulted in unprecedented efficiency at the molecular level. Ionic-liquid systems showed promising opportunities in the development of green and sustainable technologies; however, the chemical nature of ionic liquids is not intrinsically green. Many ionic liquids were found to be toxic or even highly toxic towards cells and living organisms. In this Review, we show that biological activity and cytotoxicity of ionic liquids dramatically depend on the nature of a biological system. An ionic liquid may be not toxic for particular cells or organisms, but may demonstrate high toxicity towards another target present in the environment. Thus, a careful selection of biological activity data is a must for the correct assessment of chemical technologies involving ionic liquids. In addition to the direct biological activity (immediate response), several indirect effects and aftereffects are of primary importance. The following principal factors were revealed to modulate toxicity of ionic liquids: i) length of an alkyl chain in the cation; ii) degree of functionalization in the side chain of the cation; iii) anion nature; iv) cation nature; and v) mutual influence of anion and cation. [ABSTRACT FROM AUTHOR]

In the present work, experiments have been carried out with a focus to reduce the volume requirement of solvent by mixing with imidazolium based ionic liquids (ILs) for the solvent extraction of phenol, p-chlorophenol, 2,4-dichlorophenol, 2,4,6-trichlorophenol, and pentachlorophenol from aqueous solutions. The effect of aqueous phase pH (2-12), agitation speed (100-450 rpm), solute concentration in feed (2-50 mg/L), temperature (303-333 K), treat ratio (1-11), and 1-butyl-3-methyl imidazolium tetrafluoroborate [Bmim]+[BF4]− volume in tributyl phosphate (TBP; 0-0.7% v/v) on extraction of phenols has been studied and optimized. Parameters like strip phase pH (3-13) and stripping agent concentration (0.001-0.009 N) have also been studied for stripping of phenols from solvent phase. It has been found that 0.5% v/v of ionic liquid [Bmim]+[BF4]− in solvent TBP extracts more than 97.5% of phenol and chlorophenols from aqueous solutions with a treat ratio (aqueous to solvent phase ratio) of 5. Transport mechanism for extraction and stripping of phenol and chlorophenols using ionic liquid [Bmim]+[BF4]− has been discussed. The results show that by appropriate selection of extraction and stripping conditions, it is possible to remove nearly all phenols with a treat ratio of 5. [ABSTRACT FROM AUTHOR]

Silylamine reversible ionic liquids were designed to achieve specific physical properties in order to address effective CO2 capture. The reversible ionic liquid systems reported herein represent a class of switchable solvents where a relatively non-polar silylamine (molecular liquid) is reversibly transformed to a reversible ionic liquid (RevIL) by reaction with CO2 (chemisorption). The RevILs can further capture additional CO2 through physical absorption (physisorption). The effects of changes in structure on (1) the CO2 capture capacity (chemisorption and physisorption), (2) the viscosity of the solvent systems at partial and total conversion to the ionic liquid state, (3) the energy required for reversing the CO2 capture process, and (4) the ability to recycle the solvents systems are reported. [ABSTRACT FROM AUTHOR]