氯化胆碱/尿素和氯化胆碱/甘油的性质与应用

作为绿色溶剂,离子液体在化学和物理学科引起广泛关注.低共融溶剂,如氯化胆碱/尿素和氯化胆碱/甘油,不仅被认为是一类新型的离子液体,还具有价格低廉、环境友好及合成简便等优势.为了促进氯化胆碱/尿素和氯化胆碱/甘油这两种低共融溶剂的应用,本文考察了氯化胆碱/尿素和氯化胆碱/甘油的微观结构、物理化学性质及水分对其物性的影响,并将其与传统离子液体进行了比较.此外,还分析了氯化胆碱/尿素和氯化胆碱/甘油在摩擦学及CO2分离中的潜在应用.已有研究结果表明,氯化胆碱/尿素和氯化胆碱/甘油有希望应用于摩擦学及CO2分离中,但是在大规模工业应用之前依然存在很多不确定性和瓶颈,还需要进一步在其纳米结构、实验测定及模型等方面进行研究.     

Evaluation of green and efficient deep eutectic solvents as media for extracting alkaloids from lotus leaf

Deep eutectic solvents (DESs) were applied as eco-friendly solvents in this study for the extraction of alkaloids from lotus leaf, including O-nornuciferine, N-nornuciferine, nuciferine and roemerine. A series of hydrophilic and hydrophobic DESs with different hydrogen bond donors and a acceptors were synthesized and screened for a suitable DESs for extraction of alkaloids from lotus leaf. The study results showed that the hydrophilic DES with choline chloride and propanediol had the highest extraction yield. The main factors affecting the extraction efficiency—choline chloride–propanediol ratio, water content in deep eutectic solvents, solid–liquid ratio and extraction time—were investigated via a single-factor experiment. The optimized extraction conditions were 30% of water in choline chloride–propanediol (1:4) for heated extraction for 30 min and solid–liquid ratio 1:100 g/ml. Under optimum conditions, the extraction yields of O-nornuciferine, N-nornuciferine, nuciferine and roemerine were 0.069, 0.152, 0.334 and 0.041 g/100 g respectively, which were higher than those of methanol in acidified aqueous solution. This study suggests considerable potential for DESs as promising materials for the green and efficient extraction solvents for bioactive alkaloids from natural sources.     

Deep eutectic solvents as green media for efficient extraction of terpene trilactones from Ginkgo biloba leaves

Deep eutectic solvents (DESs)-based ultrasonic extraction of terpene trilactones (TTLs) from Ginkgo biloba leaves was efficiently developed. Sixteen DESs were prepared, and DESs composed of choline chloride-urea (ChCl-U) and betaine-ethylene glycol (BE-EG) gave higher TTL extraction yields than the present, most efficient solvent 70% ethanol. The extraction conditions were further optimized, and the optimum conditions were as follows: taking BE-EG containing 40% (w/w) water as the extraction solvent, 1:10 of G. biloba leaves powder-to-solvent ratio, and ultrasonic treatment at 45°C and 100?W for 20?min. A total extraction yield of 1.94?±?0.03?mg/g was obtained under the optimum conditions, which indicated that 99.37% of TTLs could be extracted from the G. biloba leaves powder by a single extraction. Moreover, the polyamide resin was used to recover the TTLs in DES extracting solution, and recovery yield of 95.1% was attained. Therefore, BE-EG containing 40% (w/w) water was a potential alternative solvent for TTLs extraction from G. biloba leaves.     

One-pot rapid synthesis of 4H-1-benzopyran derivatives in a deep eutectic solvent

A method for introducing a biologically active heterocycle, 2-methylquinoline into the 4-position of a 2-amino-4H-1-benzopyran skeleton is described. Choline chloride/glucose (1:1 molar ratio) was used as both the solvent and catalyst in the reaction of a salicylaldehyde, methylquinoline, and cyanoacetate to obtain 2-amino-4H-1-benzopyran derivatives in 48%–80% yields after short reaction times. The effects of the deep eutectic solvent type, substrate molar ratio, cosolvent, temperature, and reaction time were examined. The method has the advantages of simple steps, environmental friendliness, mild conditions, and wide substrate applicability. This is the first attempt to synthesize methylquinoline derivatives of 4H-1-benzopyran.     

Deep eutectic solvents as both active fillers and monomers for frontal polymerization

The deep eutectic solvents (DESs) based on the mixtures of a variety of ammonium salts and hydrogen bond donors containing acrylic acids and acrylamides are capable of sustaining frontal polymerization (FP). The selection of ammonium salt affects the reactivity and allows FP at relatively low temperature but with full conversion. Also, full conversion allows us to use these polymers for biomedical applications (e.g., drug delivery systems) as the unreactive ammonium salts can be released from the resulting polymer without by‐products. We call these components “active fillers,” which can be ammonium salts with biological or pharmaceutical importance. For instance, we prepared poly(acrylic acid) loaded with lidocaine hydrochloride (a common anesthetic), the release of which was found to occur in a controlled fashion. The ammonium salts also create a sufficiently high viscosity to suppress buoyancy‐driven convection without additional materials. The DES here described played an all‐in‐one role, providing the monomer, the active filler, and the polymerization medium for FPs. © 2013 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013     

Deep eutectic silsesquioxane hybrids with quaternary ammonium/urea derivatives: synthesis and physicochemical and ion-conductive properties

We report the synthesis of deep eutectic silsesquioxane hybrids (DE-SQs) by simple mixing of quaternary-ammonium-containing SQ and urea derivatives. Cationic SQ, which was prepared by the hydrolytic condensation of a triethoxysilane precursor derived from 2-(dimethylamino)ethyl acrylate, followed by a quaternization reaction with methyl iodide, was used as a quaternary-ammonium-containing SQ component. Cationic SQ reacted with urea at a 1:2 M ratio at 80 °C for 48 h to yield a viscous DE-SQ (2Urea) liquid with a low glass transition temperature (T_g = ?11 °C). Urea derivatives—1,3-dimethylurea (DMU) and 1,3-dimethylthiourea (DMTU)—were additionally used as hydrogen bond donors to form low-T_g DE-SQs. The thermal, physical, and ion-conductive properties of the DE-SQ family of organic–inorganic hybrids were investigated and characterized, and the influences of the nature of the urea derivative and their feed ratios on DE-SQ formation were evaluated. Among the DE-SQs developed in this study, DE-SQ (2Urea) and DE-SQ (2DMTU) achieved the highest ionic conductivity, with DE-SQ (2Urea) exhibiting 2.35 × 10^?6 and 6.63 × 10^?4 S cm^?1 at 25 and 75 °C, respectively, under anhydrous conditions. This is the first report on the synthesis of DE-SQs by simple mixing of two solids, wherein the resulting compounds exhibit low T_g, thermal stability, and characteristic ionic conductivity. The ability to incorporate unique DE units into the SQ structure facilitates the development of advanced organic–inorganic hybrid materials possessing a wide range of functions and applications.     

Deep eutectic solvents for the purification of chloromycetin and thiamphenicol from milk

Deep eutectic solvents were used in both dispersive liquid–liquid microextraction and solid‐phase extraction for the purification of chloromycetin and thiamphenicol from milk. In the dispersive liquid–liquid microextraction procedure, deep eutectic solvents mixed with chloroform at different ratios (0:1–5:1, v/v) were used as the extraction agent to optimize the procedure, and the ratio of 2:1 v/v was found to be the best extraction agent with 87.23 and 83.17% recoveries of chloromycetin and thiamphenicol, respectively. Furthermore, deep eutectic solvents were also used to modify molecular imprinted polymers in solid‐phase extraction procedure, and the polymers were used to purify chloromycetin and thiamphenicol from milk. Fourier transform infrared spectroscopy, and nuclear magnetic resonance spectroscopy were used to characterize the polymers. The solid‐phase extraction recoveries with deep eutectic solvents with molecularly imprinted polymers (chloromycetin and thiamphenicol, two templates), molecularly imprinted polymers (without deep eutectic solvents), and nonimprinted polymers (without a template) for chloromycetin were 91.23, 82.64, and 57.3%, respectively, and recoveries for thiamphenicol were 87.02, 79.03, and 52.27%, respectively. The recoveries of chloromycetin and thiamphenicol from milk in the solid‐phase extraction procedure were higher than using deep eutectic solvents mixed with chloroform as the extraction agent in the dispersive liquid–liquid microextraction procedure.     

Glycerol and Glycerol-Based Deep Eutectic Mixtures as Emerging Green Solvents for Polyphenol Extraction: The Evidence So Far

The acknowledgement that uncontrolled and excessive use of fossil resources has become a prime concern with regard to environmental deterioration, has shifted the orientation of economies towards the implementation of sustainable routes of production, through the valorization of biomass. Green chemistry plays a key role in this regard, defining the framework of processes that encompass eco-friendly methodologies, which aim at the development of highly efficient production of numerous bioderived chemicals, with minimum environmental aggravation. One of the major concerns of the chemical industry in establishing sustainable routes of production, is the replacement of fossil-derived, volatile solvents, with bio-based benign ones, with low vapor pressure, recyclability, low or no toxicity, availability and low cost. Glycerol is a natural substance, inexpensive and non-toxic, and it is a principal by-product of biodiesel industry resulting from the transesterification process. The ever-growing market of biodiesel has created a significant surplus of glycerol production, resulting in a concomitant drop of its price. Thus, glycerol has become a highly available, low-cost liquid, and over the past decade its use as an alternative solvent has been gaining unprecedented attention. This review summarizes the utilization of glycerol and glycerol-based deep eutectic mixtures as emerging solvents with outstanding prospect in bioactive polyphenol extraction.     

A mini review on synthesis,properties and applications of deep eutectic solvents

Organic solvents have been of great importance for many chemical synthesis, storage and separation processes. The industries and research laboratories are heavily dependent on organic solvents in bulk; are highly volatile, lipophilic, toxic and causes a number of issues to the human health and the environmental fitness. Neoteric solvents have been proposed as a better substitute to these harmful organic solvents, and scientists have come up with several neoteric solvents in the last three decades, to name a few: ionic liquids (ILs), switchable solvents, bio-based solvents and deep eutectic solvents (DESs). These neoteric solvents attract a great deal of interest from the scientific community due to plenty of possibilities, therefore, they have huge impact and novel studies are reported quite frequently on the same. In this review, we intend to focus to brief on deep eutectic solvents, about their properties, synthesis, promising applications, and how they gradually emerged from ILs and later stood out as a different class of neoteric solvent, which overcomes many shortcomings of ILs. DESs are possibly receptive synthetic compounds and their relationship based on the hydrogen bond donor or acceptor restricts their reactivity and allow to explore in different disciplines of science.     

Basic deep eutectic solvents as reactant,template and solvents for ultra-fast preparation of transition metal oxide nanomaterials

Developing a new type of deep eutectic solvents(DESs) is indispensable for expanding their application in various fields.Here,we report a series of new highly basic DESs.FT-IR,quantitative ~1 H NMR,MD simulation and physical properties show that these basic liquids are made up of hydroxide acceptor of alkali metal hydroxides in which the hydrogen bonding interactions coordinate the donor.These DESs can be played three roles as new solvents,template and reactant for facile and ultra-fast preparation of transition metal oxide nanomaterials such as NiCo_2 O_4,MnCo_2 O_4,NiMn_2 O_4,CoCu_2 O_4 and Co_3 O_4 under mild condition.This work shows one of the low energy-intensive methods for nanomaterial preparation.These initial findings of basic deep eutectic solvents provide a potential applicability around the systematic development of transition metal oxide nanosheets.     

Deep eutectic solvent-assisted one-pot synthesis of 2-aminothiazole and 2-aminoxazole derivatives

Choline chloride–urea-based deep eutectic solvent (DES) has been found to be a highly effective catalyst and reaction medium for the one-pot synthesis of 2-aminothiazole and 2-aminoxazole derivatives. Three-component reactions of active methylene compounds, urea or thiourea and N-bromosuccinimide NBS in deep eutectic solvent furnished structurally diverse 2-aminoxazoles and 2-aminothiazoles in good to excellent yields under mild reaction conditions and short reaction times. DES is inexpensive, biodegradable and more accessible in any laboratory and industry.     

低共熔溶剂用于高效可逆捕集二氧化碳的研究

本文通过一步合成法合成了四种不同摩尔比的四乙基氯化胺-乙醇胺低共熔溶剂（TEAC-MEA DES）。红外光谱表征分析表明该DES是依靠氢键作用而形成的;DES的热稳定性高于MEA,且随着MEA的比例的增加而降低;对不同比例的DES进行了四次循环CO₂吸收-解吸实验,发现其吸收容量几乎不变,重复使用性能较好。在不同温度下计算了化学平衡常数,lnK对1/T线性拟合结果表明DES吸收CO₂的反应焓是负值,即吸收CO₂的反应是放热过程。该DES在吸收CO₂方面具有很大的潜力。     

Urea decomposition: Efficient synthesis of pyrroles using the deep eutectic solvent choline chloride/urea

A simple and efficient method is reported for the synthesis of pyrroles via condensation of a series of tricarbonyl compounds with ammonia, which was generated in situ from decomposition of the deep eutectic solvent choline chloride/urea.     

A simple and efficient sample preparation for taxanes in Taxus chinensis needles with natural menthol‐based aqueous deep eutectic solvent

Taxanes are natural anticancer constituents, and the sample preparation from matrix normally depends on organochlorine solvents. In this study, green and natural menthol‐based aqueous deep eutectic solvent was synthesized and used for sample preparation for taxanes. Five key parameters were optimized and the optimal preparation conditions were as follows: menthol/1‐propanol ratio 1:1 (mol/mol), solid–liquid ratio 1:30 g/mL, extraction time 30 min, ultrasonic power 250 W, and water content 80%. Under the above conditions, the total extraction efficiency of seven main taxanes was 1.25‐ to 1.44‐fold to the conventional methods. In addition, a high‐performance liquid chromatography method with C₁₈ column was established for quantitation of seven main taxanes in <25 min, which had excellent linearity (R² > 0.9986), precision (relative standard deviation < 3.00%), repeatability (relative standard deviation < 3.69%), and recovery (90.26–109.00%). This method performed the extraction, and enrichment processes simultaneously, and it had advantages such as high extraction efficiency, simple operation, low cost, and eco‐friendliness. This work indicated that the natural menthol‐based deep eutectic solvent aqueous could be an excellent alternative to the sample preparation from Taxus or other plants.     

Rapid synthesis of aurones under mild conditions using a combination of microwaves and deep eutectic solvents

The combination of microwave heating and the deep eutectic solvent formed from choline chloride and urea has resulted in a new, essentially neutral, yet rapid method for the synthesis of a wide range of aurone derivatives. While isolated yields remain somewhat variable, in virtually every case, a significant increase in yield has been observed on going from conventional thermal heating to microwave heating. In addition, some compounds inaccessible using prior methods have become reproducibly available using this modification. Further application of the combination of DES and microwave heating is expected to be highly promising and of general utility.     

Novel diethanolamine based deep eutectic mixtures for carbon dioxide (CO2) capture: synthesis and characterisation

In this work, diethanolamine was successfully used as a hydrogen bond donor to prepare three different deep eutectic solvents (DESs) using three quaternary ammonium salts at different molar ratios. Important physical properties of the prepared DESs including melting point, glass transition, crystallisation temperature, density, refractive index and viscosity were measured in temperature ranging from (298.15 to 358.15 K). Moreover, in order to explore the changes in chemical structures of the DESs, FTIR analysis was performed. The developed DESs have melting points lower than 293.15 K, and of significantly low density (close to water) and comparable viscosity. The effect of temperature and molar ratio on physical properties were also discussed. Empirical models were used to correlate the density, refractive index and viscosity data of the DESs as a function of temperature and molar ratio. A quantitative analysis, also called as ANOVA analysis, was conducted to investigate the significance of the experimental physical properties data. The new DESs prepared in this work have a potential to be used in numerous applications including CO₂ capture.     

低共熔溶剂——新型亲水作用色谱流动相改性剂

低共熔溶剂被用作亲水作用色谱流动相的新型改性剂。选用硅胶柱(150 mm×4.6 mm, 3 μm),以乙腈与低共熔溶剂(氯化胆碱-乙二醇(摩尔比为1:3))的混合溶液为流动相,考察了6个碱基与核苷的色谱分离效果,并讨论了低共熔溶剂在流动相中的比例及温度条件对分离的影响。结果表明,与传统的水相流动相条件相比,在加入低共熔溶剂改性后的流动相条件下,碱基与核苷分离效果得到明显的改善,尤其是胞嘧啶与胞苷能达到完全分离;同时,随着低共熔溶剂在乙腈中浓度的增加,6个碱基与核苷在色谱柱上的保留均有不同程度的减小,其中胞苷的保留减小最为显著;随着柱温的升高,碱基与核苷的保留同样有所减小。本文验证了低共熔溶剂作为亲水作用色谱流动相改性剂的可行性,可在一定程度上解决传统亲水作用色谱分离的困难。     

Choline chloride based eutectic solvent for the efficient synthesis of 2-amino-4H-chromen-4-yl phosphonate derivatives via multicomponent reaction under mild conditions

Synthesis of 2-amino-4H-chromen-4-ylphosphonate derivatives has been accomplished by the one-pot three-component reaction of salicylaldehyde, malononitrile/ethylcyanoacetate and dialkyl phosphites in the presence of reusable deep eutectic solvent (DES) under mild conditions. The advantages of this method are mild reaction conditions, simple work-up procedure, use of DES as a green solvent and an economical protocol for the preparation of important biologically active phosphorus-containing compounds.     

Deep eutectic solvent an efficient reaction medium for the synthesis of chromeno pyrazolo and indazolo phthalazine derivatives

The volatile, harmful and hazardous solvents have impact on human health, all organisms and environment. To reduce the use of hazardous volatile solvents, there is need to develop the alternative green reaction medium for organic transformations and is the main goal of green chemistry. The green solvent should be nonvolatile, nontoxic, biodegradable and biorenewable. Considering these parameters, herein, we have reported an efficient and environmentally benign green synthesis of chromeno pyrazolo and indazolo phthalazine derivatives in deep eutectic solvent. The present protocol contains excellent yield of the product, short reaction time, operation simplicity, reusability of solvent and no need of further purification.