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Highlights: [•] The microemulsions composed of cholinium-based ionic liquid, Triton X-100 and water have been prepared and characterised. [•] Ternary phase diagrams of the microemulsions have been established at T =298.15K. [•] The microemulsions exhibit IL-in-water, bicontinuous and water-in-IL microstructures. [•] Droplets with the size smaller than 20nm are formed in these IL-based microemulsions. [ABSTRACT FROM AUTHOR]

Abstract: Densities, conductivity, fluorescence and UV–vis absorption spectroscopy of glycyl dipeptide+ionic liquid (1-dodecyl-3-methylimidazolium bromide ([C12mim]Br))+water mixtures have been measured at different temperatures. From density data, the standard partial molar volume , standard partial molar volume of transfer for three glycyl dipeptides from water to aqueous [C12mim]Br solutions (Δt V o), partial molar expansibility and Hepler's constant have been calculated. Through the electrical conductivity measurements, the critical micellar concentration (c cmc) and a series of thermodynamic parameters of micellization of [C12mim]Br in aqueous glycyl dipeptide solutions are evaluated. Effects of temperature and hydrocarbon chain length of the glycyl dipeptides on the volumetric properties of dipeptides and critical micelle concentration (c cmc) of [C12mim]Br were examined. The pyrene fluorescence spectra were used to study the change of micropolarity produced by the interactions of [C12mim]Br with glycyl dipeptides, and the aggregation behavior of [C12mim]Br. From the results of UV–vis absorption spectra, the binding constant between dipeptide and [C12mim]Br above the c cmc was determined. [Copyright &y& Elsevier]

Highlights: [•] The values of and Δt V° are positive. [•] Interactions of Triton X-100 with charged and polar groups of dipeptides dominate. [•] Addition of dipeptide in water decreases the c cmc and the aggregation number of Triton X-100. [•] The affinity between dipeptide and Triton X-100 micelle increases with the increase in the length of alkyl chain of peptides. [•] Triton X-100 interacts with dipeptides more weakly than SDS. [ABSTRACT FROM AUTHOR]

Nanoplasmonic sensors based on the localized surface plasmon resonance (LSPR) of noble metal nanoparticles have many advantages, such as real-time detection, no need for reagent labelling, and no use of complicated equipment. However, the nanoplasmonic sensors with two dimensional structures usually suffer from a low LSPR signal and thus low sensitivity due to the low density of the nanoparticles. In addition, complicated surface functionalization is always required to suppress the non-specific binding of the analyst to the substrate of the sensor, because the two types of surface, that is, metal and substrate surfaces, are simultaneously exposed to the reaction medium. To overcome these problems, an innovative thermal-induced method has been proposed in the present work, to construct three dimensional (3D) nanostructure of Ag nanocubes on both surfaces of the substrate by using the unique amphiphilic property of 2-diethylaminoethanethiol. The prepared nanoplasmonic sensor is highly sensitive due to the high density of 3D structure of the nanoparticles and the low non-specific binding since only one type of surface is exposed. To enhance the stability of the sensor, a thin SiO2 overlayer was formed on the surface without using an additional coupling agent. Furthermore, the NiII-nitriloacetic acid (NiII-NTA) complex was covalently bound on the surface, so that the regeneration and reuse of the sensor becomes easy. Therefore, the easy fabrication, high stability, and good reusability of this 3D LSPR sensor makes our method competitive for the development of nanoplasmonic sensors. [ABSTRACT FROM AUTHOR]

Highlights: [•] C8mim[Cl] up-regulates the expressions of CYP1A1, CYP2E1, or CYP3A in EMT6 cells. [•] CYPs may be involved in the metabolization of imidazolium-based ionic liquids. [•] C8mim[Cl]-mediated CYP3A induction may be PXR-dependent. [ABSTRACT FROM AUTHOR]

Inthis work, four 1-butyl-3-methylimidazolium carboxylate ionicliquids (ILs) with different substituent groups in anions, including1-butyl-3-methylimidazolium glycollate [C4mim][HOCH2COO], 1-butyl-3-methylimidazolium lactate [C4mim][CH3CHOHCOO], 1-butyl-3-methylimidazolium benzoate [C4mim][C6H5COO], and 1-butyl-3-methylimidazoliumglycinate [C4mim][H2NCH2COO], havebeen synthesized and characterized. Their densities (ρ) andsurface tensions (γ) have been determined experimentally inthe temperature range of (298.15 to 343.15) K. By using thermodynamicand empirical equations, molar volume (Vm), isobaric expansivity (αp), standardentropy (S°), lattice energy (UPOT), surface excess entropy (Ss), vaporization enthalpy (ΔlgHm0) and Hildebrand solubility parameter(δH) of these ILs have been derived from densityand surface tension data. The effects of substituent groups in carboxylateanions on densities and surface tensions of these ILs have been assessedfrom the analysis of the structure–property relationship. [ABSTRACT FROM AUTHOR]

A newly designed surface molecularly imprinted polymer (MIP) was developed using 4-methylimidazole as the template and ethylenediaminepoly (styrene-divinylbenzene) particles as the support material. The resulting MIP material was characterized with scanning electron microscopy, infrared spectrum, surface area, pore-size and thermal property measurements. Static adsorption, solid-phase extraction (SPE) and high-performance liquid chromatography were combined to study the adsorption characteristics and selective recognition performance of the polymer for 4-methylimidazole and its structural analogues. It was shown that the maximum binding capacities of 4-methylimidazole on the MIP and the non-imprinted polymer (NIP) were 416 and 227 μmol g-1, respectively. The binding process could be described by pseudo-second-order kinetics, and the adsorption equilibrium was achieved in 40 minutes. Compared with the corresponding NIP, the MIP exhibited much higher adsorption performance and selectivity for the template. After the separation of a mixture of 4-methylimidazole, benzimidazole and nitrophenol on the MIP-SPE and the NIP-SPE columns, the recoveries of 4-methylimidazole on the MIP-SPE and NIP-SPE columns were 96-102% and 34-39%, respectively, whereas those of benzimidazole and nitrophenol were below 19% on the two columns. In addition, more than 99% of 4-methylimidazole could be obtained on the MIP-SPE column from water and soil samples. [ABSTRACT FROM AUTHOR]

• Pd-CoO∙TiO 2 /TiO 2 and Pd-CoO x /TiO 2 represent high catalytic activity and selectivity in CO 2 transformations. • CO is a good prober toward Lewis acidic centers for the reaction intermediates of methoxy species. • Lewis acidity and alkalinity are readily controllable on the catalysts surfaces. • High catalytic performances are derived from the cooperation of Lewis acid/base on the interfaces. • The studies provide an alternative solution to relate the catalytic activity with the strengths of Lewis acids and bases. A highly attractive aim is to turn CO 2 into useful chemicals selectively and efficiently, but it still retains great challenging to understand the relations between catalytic performances and interface properties. Here, we report an alternative solution to relate the catalytic activity with the strengths of Lewis acids and bases on the Pd-CoO x interfaces. CoO∙TiO 2 /TiO 2 and CoO x /TiO 2 possess the wide spectrum of Lewis acid/base centres, and give the low selectivity and conversion. The introduction of Pd can focus them on the intrinsic centres, and makes Pd-CoO∙TiO 2 /TiO 2 and Pd-CoO x /TiO 2 represent the ideal catalysis. With temperature-programmed desorptions of CO 2 , CO and NH 3 , it is evidenced that the catalytic hydrogenations of CO 2 to CO, CH 4 and CH 3 OH depend on the cooperation of the Lewis acidic/alkaline centres on the interfaces. The studies provide guidelines for rational design and synthesis of heterogeneous catalysts including but not limited to CO 2 hydrogenation. [Display omitted] [ABSTRACT FROM AUTHOR]

• Pd-CoO∙TiO 2 /TiO 2 and Pd-CoO x /TiO 2 represent high catalytic activity and selectivity in CO 2 transformations. • CO is a good prober toward Lewis acidic centers for the reaction intermediates of methoxy species. • Lewis acidity and alkalinity are readily controllable on the catalysts surfaces. • High catalytic performances are derived from the cooperation of Lewis acid/base on the interfaces. • The studies provide an alternative solution to relate the catalytic activity with the strengths of Lewis acids and bases. A highly attractive aim is to turn CO 2 into useful chemicals selectively and efficiently, but it still retains great challenging to understand the relations between catalytic performances and interface properties. Here, we report an alternative solution to relate the catalytic activity with the strengths of Lewis acids and bases on the Pd-CoO x interfaces. CoO∙TiO 2 /TiO 2 and CoO x /TiO 2 possess the wide spectrum of Lewis acid/base centres, and give the low selectivity and conversion. The introduction of Pd can focus them on the intrinsic centres, and makes Pd-CoO∙TiO 2 /TiO 2 and Pd-CoO x /TiO 2 represent the ideal catalysis. With temperature-programmed desorptions of CO 2 , CO and NH 3 , it is evidenced that the catalytic hydrogenations of CO 2 to CO, CH 4 and CH 3 OH depend on the cooperation of the Lewis acidic/alkaline centres on the interfaces. The studies provide guidelines for rational design and synthesis of heterogeneous catalysts including but not limited to CO 2 hydrogenation. [Display omitted] [ABSTRACT FROM AUTHOR]

[Display omitted] • Pyridinolate-based functional ILs with different structures were designed for SO 2 capture. • Anion order of SO 2 capacity is [4-PyO] > [3-PyO] > [2-PyO]. • Cation order of SO 2 capacity is [P 66614 ] > [P 4442 ] > [TMG]. • Viscosity of system increased first and then decreased with the increase of absorption capacity. A series of pyridinolate anion-functional ionic liquids (ILs) containing different kinds of cations were designed and prepared, including tri- n -hexyltetradecylphosphonium [P 66614 ], tri- n -butylethylphosphonium [P 4442 ], and 1,1,3,3-tetramethylguandinium [TMG] cations and pyridinolate [PyO] anions with different N positions. Densities and viscosities at different temperatures were measured because of their importance for the absorption of SO 2. Effect of different structures on the absorption of SO 2 was studied, including the type and the alkyl chain length of cations, and the N positions of [PyO] anions (2-, 3-, and 4-). Additionally, effects of SO 2 concentration and temperature for absorption were investigated. Especially, up to 6.00 and 2.53 mol SO 2 per mole IL could be obtained by [P 66614 ][4-PyO] at 1 bar and 0.1 bar of SO 2 , respectively, when absorptions performed at 20 °C. The results indicate that (1) the aprotic cations weakened the cation⋯anion interaction and resulted in the released active sites on the anions, and (2) N position has an influence on charge distribution of [PyO] anions and resulted in the tunable absorption of SO 2. Reversible SO 2 absorption and [P 66614 ][4-PyO] regeneration could be performed several times without losing efficiency. Furthermore, the mechanism of absorption was studied through FT-IR and NMR methods and the results showed that the absorption of SO 2 by [P 66614 ][4-PyO] includes physisorption and chemisorption. [ABSTRACT FROM AUTHOR]

In many practical processes, separation of aliphatic amines from aromatic amines in water is imperative to obtain the desired products. In this work, a novel strategy was proposed for selective separation of aliphatic amines from aromatic amines with CO2 switchable ionic liquids (ILs) aqueous two-phase systems (ATPSs). It was shown that upon introduction of CO2 into an aqueous solution containing the IL, aliphatic amine and aromatic amine at 25 °C and atmospheric pressure, an ATPS could be formed with an IL-rich top phase and an ammonium-salt-rich bottom phase. Under these circumstances, the aromatic amine was largely partitioned in the IL-rich phase, while the aliphatic amine was transformed into the ammonium salt by the reaction with CO2. Thus the aliphatic amine was well separated from the aromatic amine in aqueous solution. The distribution ratios of aromatic amines between the two phases were found to increase with increasing hydrophobicity of ILs and aromatic amines, pKa values of aliphatic amines and tie-line length of the systems. Moreover, aliphatic amines retained in the ammonium-salt-rich phases were regenerated by bubbling N2 under heating, while aromatic amines in the IL-rich phases were removed by simple steam distillation. The recovery efficiency for aliphatic amines was as high as 99.0%. The regenerated ILs could then be reused in the next separation process, and no decrease in the distribution ratios of aromatic amines was observed after six cycles. [ABSTRACT FROM AUTHOR]

Abstract: In this work, a series of novel room temperature ionic liquids (ILs) have been synthesized with cheap, naturally α-amino acid ester as cations and bis(trifluoromethylsulfonyl)imide as anion. The glass transition temperature and thermal decomposition temperature of these ILs, partition coefficients of some coumarins and purine alkaloids between water and the amino acid ester-based ILs at T =298.15K, and Gibbs energy, enthalpy and entropy changes for the transfer of caffeine and 6,7-dihydroxycoumarin from water to [LeuC2][Tf2N] have been determined. It is shown that these ILs are highly effective materials for the extraction of drug compounds like coumarin, 4-hydroxycoumarin, 7-hydroxycoumarin, 3-aminocoumarin, coumarin-3-carboxylic acid, 6,7-dihydroxycoumarin, 6,7-dihydroxy-4-methylcoumarin, caffeine, theobromine, theophylline, inosine, and 2,6-diaminopurine. The partition process is driven by enthalpy term, and partition coefficients of the drug molecules increase with the increase of hydrophobicity of both the drug molecules and the ILs. Furthermore, the possible partition mechanism has been investigated from 13C NMR measurements. [Copyright &y& Elsevier]

Abstract: Ionic liquids (ILs) have potential applications in many areas of chemical industry because of their unique properties. However, it has been shown that the ILs commonly used to date are toxic and not biodegradable in nature, thus development of efficient chemical methods for the degradation of ILs is imperative. In this work, degradation of imidazolium, piperidinium, pyrrolidinium and morpholinium based ILs in an ultrasound and zero-valent iron activated carbon (ZVI/AC) micro-electrolysis system was investigated, and some intermediates generated during the degradation were identified. It was found that more than 90% of 1-alkyl-3-methylimidazolium bromide ([C n mim]Br, n = 2, 4, 6, 8, 10) could be degraded within 110 min, and three intermediates 1-alkyl-3-methyl-2,4,5-trioxoimidazolidine, 1-alkyl-3-methylurea and N-alkylformamide were detected. On the other hand, 1-butyl-1-methylpiperidinium bromide ([C4mpip]Br), 1-butyl-1-methylpyrrolidinium bromide ([C4mpyr]Br) and N-butyl-N-methylmorpholinium bromide ([C4mmor]Br) were also effectively degraded through the sequential oxidization into hydroxyl, carbonyl and carboxyl groups in different positions of the butyl side chain, and then the N-butyl side chain was broken to form the final products of N-methylpiperidinium, N-methylpyrrolidinium and N-methylmorpholinium, respectively. Based on these intermediate products, degradation pathways of these ILs were suggested. These findings may provide fundamental information on the assessment of the factors related to the environmental fate and environmental behavior of these commonly used ILs. [Copyright &y& Elsevier]

A series of choline-based ionic liquids (CIL) have been synthesized in this work. The results suggested that both the cations and the anions have significant influences on their properties such as thermostabilities, acidities and their performances for the synthesis of 3,4-dihydro-2(H)-pyrimidinones. The optimized catalytic system based on the CIL [DMEA][HSO] for the Biginelli reactions benefits from the wide substrates tolerance, benign reaction conditions, easy work-up procedures, and the feasible reusability of the ionic liquid. Graphical Abstract: The thermostabilities, acidities, and the catalytic activities for the Biginelli reactions are all follows the sequence of [DMEA][HSO] > [Choline] [HSO] > [DMEA][HPO] > [Choline] [HPO][Figure not available: see fulltext.]. [ABSTRACT FROM AUTHOR]

Abstract: Searching for environmentally friendly aqueous two-phase systems is imperative for the sustainable development of bioseparation technologies. In the present work, (liquid+liquid) equilibrium data have been determined experimentally for aqueous two-phase systems formed by the cholinium-based ionic liquids (cholinium glycollate, cholinium propionate, cholinium lactate, and choline chloride) and polymers {polypropylene glycol 400 (PPG400), polypropylene glycol 1000 (PPG1000), and poly(ethylene glycol)-block-poly(propylene glycol)-poly(ethylene glycol) (EO10PO90)}. The effects of anion type of the ionic liquids, the nature of the polymers and temperature of the systems are examined on the phase-forming capacity of the systems. Then the binodal results have been satisfactorily fitted to a three-parameter empirical equation. The tie-line data are well described by the Othmer–Tobias and Bancroft equations. [Copyright &y& Elsevier]

Abstract: Ionic liquids (ILs) are promising in the capture and separation of CO2. In this work, IL 1-n-butyl-3-methylimidazolium heptafluorobutyrate, [C4mim][CF3CF2CF2COO], has been synthesized and characterized by 1H, 13C and 19F NMR spectra. Solubilities of CO2, H2, N2 and O2 in this IL have been determined at the temperature range from (303.15 to 333.15)K and the pressure up to 8.9MPa. From these data, the Henry’s constant, the standard state solution Gibbs energy, standard state solution enthalpy and standard state solution entropy of these gases in [C4mim][CF3CF2CF2COO] were derived and analyzed from molecular interactions. It was shown that the solubility of CO2 is obviously higher than that in [C4mim][CF3COO] and [C4mim][CF3SO3] reported in literature, which makes this IL an attractive solvent for gas separation processes. Furthermore, these solubility data were well correlated by Pitzer model. [Copyright &y& Elsevier]

Abstract: It has been reported that ionic liquids (ILs) are commonly toxic in nature, and thus the removal of ILs in various environmental systems would be of great significance. In this work, an ultrasonic irradiation and zero-valent iron activated carbon (ZVI/AC) micro-electrolysis system was applied to degradation of 1-butyl-3-methylimidazolium chloride ([C4mim]Cl) residues in water. The experimental conditions were optimized, and the degradation processes were investigated by using UV, HPLC and GC–MS techniques. It was found that more than 95% of [C4mim]Cl could be degraded in aqueous solution and 81% of [C4mim]Cl could be mineralized within 110min, and the degradation could be described by a pseudo-first-order kinetics. The presence of hydroxyl radical scavenger can greatly reduce the reaction rate but could not prevent degradation of [C4mim]Cl. GC–MS analyses demonstrated that this degradation led to the formation of 1-butyl-3-methyl-2,4,5-trioxoimidazolidine, 1-butyl-3-methylurea and N-butylformamide. On the basis of these intermediates, degradation pathway was also suggested. These results indicate that ZVI/AC micro-electrolysis with ultrasonic irradiation degradation could serve as an efficient treatment technology for removing [C4mim]Cl from wastewater. [Copyright &y& Elsevier]

Abstract: The interactions of glycyl dipeptides (glyglycine, glycyl-l-valine and glycyl-l-leucine) with sodium perfluorooctanoate (SPFO) in aqueous solutions have been investigated by means of density, conductivity, fluorescence spectroscopy, and UV–vis spectroscopy. The standard partial molar volume (), standard partial molar volume of transfer for dipeptide from water to aqueous SPFO solutions (Δt V o), partial molar expansibility () and Hepler’s constant have been calculated from density data. Electrical conductivity was used to estimate the critical micellar concentration (ccmc) and the thermodynamic parameters of micellization of SPFO in aqueous glycyl dipeptide solutions. Effects of temperature and hydrocarbon chain length of the glycyl dipeptides on the volumetric properties of dipeptides and critical micelle concentration (ccmc) of SPFO were examined. The pyrene fluorescence spectra were used to study the change of micropolarity produced by the interactions of SPFO with glycyl dipeptides, and the aggregation behaviour of SPFO. From the results of UV-vis absorption spectra, the binding constant between dipeptide and SPFO above the ccmc was determined. [Copyright &y& Elsevier]

Abstract: In this work, the hydrogen bond formation ability of cation and anion of the ILs was determined by using the solvatochromic method and was found to be responsible for their catalytic activity in the Knoevenagel reactions. The enhancement in the hydrogen bond donor ability of the cations and the hydrogen bond acceptor ability of the anions can both lead to the increase in the catalytic activity of the ILs. From the proposed reaction mechanism, it was deduced that the cations of the ILs can form hydrogen bond with aldehyde to activate the C electrophile, and the anions of the ILs can promote active methylene compound to produce carboanion as nucleophile, showing dual function activation effect in the catalytic processes. In addition, the optimized N,N-dimethylethanolamnium acetate as dual function activator for the Koevenagel reactions benefits from wide substrates tolerance, ambient reaction temperature, easy work-up procedure, and easy reuse of the IL. [Copyright &y& Elsevier]

Ionic liquids have gained more attention due to their excellent properties in many different scientific fields. However, previous researches indicated that ionic liquids have adverse effects on organisms. The objective of this study was to evaluate the effects of 1-octyl-3-methylimidazolium bromide ([Cmim]Br) on the aquatic plant duckweed ( Lemna minor) by exposure of the plant to 0.25 to 2 mg L of [Cmim]Br for 28 days. Exposure to [Cmim]Br significantly decreased the photosynthetic pigment contents at 21 and 28 days. The activities of superoxide dismutase and catalase and the total antioxidant capacity level increased at 7 days of exposure and decreased at the termination of exposure. In contrast, the HO content and peroxidase activity in all treatments increased during the period of exposure. Furthermore, marked increase of malondialdehyde content occurred in duckweed after 21 to 28 days of exposure. In addition, reactive oxygen species (ROS) scavenger dimethyl thiourea prevents duckweed from oxidative damage caused by [Cmim]Br. These results suggest that ROS might be involved in the mechanism of ionic liquid-induced toxicity in L. minor. [ABSTRACT FROM AUTHOR]

Abstract: Highly effective cellulose solvents for the dissolution of cellulose at ambient temperature have been designed by adding any aprotic polar solvent to 1-butyl-3-methylimidazolium acetate ([C4mim][CH3COO]). The effects of molar ratio of the aprotic polar solvents to [C4mim][CH3COO], anionic structure of the ionic liquids (ILs) and nature of the co-solvents on cellulose solubility have been studied in detail. The enhanced dissolution of cellulose is suggested to be mainly resulted from the preferential solvation of cations of the ILs by the aprotic polar solvents, and this has been supported by our conductivity measurements. [Copyright &y& Elsevier]

Abstract: Micellization and related thermodynamic parameters of a conventional anionic surfactant sodium dodecyl sulfonate (C12SO3Na) in various compositions of water–dipeptide mixed media have been studied by means of conductivity and fluorescence spectroscopy at five temperatures ranging between 298.15K and 318.15K. The electrical conductivity data have been utilized to calculate the values of critical micelle concentration (c cmc) and the counterion binding constant (β) of C12SO3Na. From c cmc values, it is observed that the micellization tendency of the surfactant increases in the presence of dipeptides. Thermodynamic parameters (ΔG m o, ΔH m o and ΔS m o) of micellization of C12SO3Na in aqueous dipeptide solutions have been obtained by applying the mass action model and an enthalpy–entropy compensation effect was observed. The effect of dipeptides on the micellar properties of C12SO3Na depends upon their nature and concentration, as well as the temperature. The pyrene fluorescence spectra were used to study the change of micropolarity produced by the interaction of C12SO3Na with dipeptides, and the aggregation behavior of C12SO3Na. The results have been interpreted in terms of solute–solvent interactions and structural changes in the mixed solutions. The interaction difference of C12H25SO3Na/C12H25SO4Na with dipeptides was also studied and it was found that C12H25SO3Na were seen to interact more weakly than their sulfate analogues. [Copyright &y& Elsevier]

Abstract: The feasibility of the newly synthesized ionic associates L1 and L2 formed by ionic liquid [C4mim][PF6] and cationic dyes (malachite green and methylene blue) has been tested as a novel ionophore for the preparation of anion-selective polymeric membrane electrodes. The electrode exhibits Nernstian response and enhanced potentiometric selectivity towards [PF6]− compared to many other anions. The influence of some experimental parameters such as membrane composition, nature of plasticizer and amount of additive on the potential response of the [PF6]− sensor are investigated. Under the optimized conditions, the response slopes of the membrane electrodes towards [PF6]− are 59.7±0.5 and 58.1±0.5mV/decade based on ionophore L1 and L2, respectively, in 1.0×10−5–1.0×10−1 or 1.0×10−6–1.0×10−1 mol/L concentration range. Interestingly, the optimized electrodes based on ionophores L1 and L2 also exhibit Nernstian response characteristics (60.3±0.5 and 56.0±0.5mV/decade) for tetrafluoroborate anion [BF4]− in a wide concentration range. Thus, the proposed sensor has been used for the determination of [PF6]− and [BF4]− in aqueous ionic liquids samples and the solubility of the [PF6]− and [BF4]− based ionic liquids in water. The satisfactory results are obtained. [Copyright &y& Elsevier]

In this paper, a catalyst-free synthesis of diversely substituted 6H-benzo[c]chromenes and 6H-benzo[c]chromen-8-ols via cascade reactions of 2-(2-(allyloxy)phenyl)furan and 2-(2-(prop-2-ynyloxy)phenyl)furan, featured with intramolecular Diels–Alder reactions of furan with unactivated alkene/alkyne in aqueous media under MWI, was developed. In addition, an environmentally friendly oxidation of 6H-benzo[c]chromenes into the corresponding benzo[c]chromen-6-ones using aqueous H2O2 as an oxidant, in the absence of any activator/catalyst, was also revealed. [ABSTRACT FROM AUTHOR]

Abstract: A novel method was proposed for successful fabrication of CuS nanostructures with various morphologies. At the ionic liquids (ILs)-modulated CHCl3–H2O interface, copper cupferronate [Cu(cup)2] in CHCl3 reacted with thiourea in water to generate CuS nanostructures via a solvothermal reaction process. The effects of alkyl chain length of imidazolium cations and nature of anions of the ILs, molar ratio of Cu(cup)2 to thiourea, the reaction temperature and time on the morphology of the products were studied systematically. It was shown that by changing alkyl chain length of imidazolium cations and nature of anions of the ILs, CuS nanostructures with various morphologies, including flowers, urchins, large nanodisks and nanoparticles, could be obtained at the liquid–liquid interface, and the ILs played important template roles in directing the formation of CuS nanostructures. Furthermore, the as-prepared CuS samples exhibited high catalytic activity for photodegradation of methyl orange and thermal decomposition of ammonium perchlorate. [Copyright &y& Elsevier]

Density functional theory calculations were performed to investigate the structural and energetic properties of NO adsorption on small bimetallic AgCu clusters ( n + m ≤ 5). Generally NO is adsorbed in bridge configuration. The adsorbates prefer Cu sites when both Ag and Cu co-exist in the clusters. The adsorption energies and the dissociation energies of the complex clusters increase as the Cu content increases for the given cluster size. Our calculation suggests that the bimetallic AgCu may react with NO dissociatively by way of Ag atom, Ag or AgCu loss. The N-O vibrational properties of the complex clusters were also discussed and analyzed. [ABSTRACT FROM AUTHOR]

Ionic liquids (ILs) have numerous applications in industrial processes as a benign alternative to conventional volatile organic solvents. However, many of them are toxic to organisms and are poorly biodegradable. In this work, a series of environmentally friendly cholinium ILs have been designed and synthesized. It was found that these ILs could form aqueous two-phase systems (ATPSs) with polypropylene glycol 400 (PPG400) which is thermo-sensitive, non-toxic and biodegradable. In order to understand the phase formation processes and possible application of these ATPSs for extraction/separation of proteins, the binodal curves and tie lines of these ATPSs were measured at 25 °C, and the effects of anionic structure of the ionic liquids, nature of the proteins and difference in the concentration of top- and bottom-phases on the partitioning behavior of some typical proteins were investigated systematically. It was shown that bovine serum albumin (BSA), trypsin, papain and lysozyme could be enriched effectively into the ionic liquid-rich phase of the ATPSs, and single-step extraction efficiency could be as high as 86.4–99.9% under the optimized conditions. Furthermore, enzyme activity of the native trypsin in water and in aqueous ionic liquid solutions was determined by using N-a-benzoyl-l-arginine ethyl ester as a substrate, and activity increases to about 127% was observed after 13 months storage. In addition, PPG400 has been recovered simply by heating and reused in the next extraction processes. This avoids the non-sustainable issue of highly salty water produced in the application of the polyethylene glycol (PEG) + salt and ionic liquid + salt ATPSs. [ABSTRACT FROM AUTHOR]

Abstract: The interactions of glycyl dipeptides (glycylglycine, glycyl-l-valine and glycyl-l-leucine) with sodium caprylate (NaC8) in aqueous solution have been investigated by a combination of density, conductivity and fluorescence methods. Apparent molar volumes (V 2, ϕ ), standard partial molar volumes (), and standard partial molar volumes of transfer from water to aqueous NaC8 solutions (Δ t V o) are evaluated using density data. The limiting molar conductivity of sodium caprylate (Λ o) and its anion contribution , as well as the Stokes’ radii of caprylate anion in aqueous glycyl dipeptide solutions have been calculated using conductivity data. Pyrene fluorescence spectra were used to estimate the critical micellar concentration (c cmc) of NaC8 in aqueous dipeptide solutions. The analysis shows that the interactions of sodium caprylate with charged and polar groups of glycyl dipeptides are dominating over the sodium caprylate-non-polar group interactions over the entire concentration range of sodium caprylate. From the volumetric data, it is suggested that the glycyl dipeptides are solubilized in the palisade layer of sodium caprylate micelles. The decrease in Λ o values of sodium caprylate with an increase in dipeptide concentration is attributed to the interaction of sodium caprylate with the dipeptides and increasing viscosity of solvent. The addition of dipeptide in water decreases the c cmc of NaC8. The interactions of glycyl dipeptides with sodium caprylate increase with the increase in the size of side chain of carboxylate anions and of glycyl dipeptides. [Copyright &y& Elsevier]

Dilution enthalpies and mixing enthalpies of sodium halideandsome saccharides (glucose, galactose, xylose, arabinose, fructose,and sucrose) in aqueous solution were determined by calorimetric measurementsat 298.15 K. The values were used to determine enthalpic pair interactionparameters. Combined with Gibbs energy pair parameters, entropic pairinteraction parameters were also obtained. Theoretical calculationsat the B3LYP/6-311(d,p) level were carried out to provide the informationof structures and thermodynamic functions. The information revealsthe thermodynamic essence of the interactions between sodium halideand saccharides in aqueous solutions. The experimental results andtheoretical calculations show that the sign of enthalpic pair interactionparameter 2υhESis determined bythe direct interaction between saccharides and ions, whereas the differencein value of 2υhESfor differentsaccharides or electrolytes depends on the partial dehydration ofsaccharides or anions in aqueous solution. The difference in valueof entropic pair interaction parameters depends partly on the differentdominant interactions in the process of partial dehydration of saccharidesor ions. An enthalpy–entropy compensation relationship wasobserved for the sodium bromide–aldopyranose–water systems.Remarkably, it can be conjectured that the hydration entropy of glucoseis lower than for other monosaccharides. Perhaps it is one of thereasons why glucose plays an important role in living organisms ratherthan other monosaccharides. [ABSTRACT FROM AUTHOR]

A simple method was developed for selective para-cyanation of alkoxy- and benzyloxy-substituted benzenes with 0.5 equivalents of potassium ferricyanide, 0.8 equivalants of copper(II) nitrate and 0.5 equivalents of iodine in acetonitrile. Among various phenyl carbon-hydrogen bonds, those at the para-position with regard to the alkoxy or benzyloxy groups were selectively cyanated in 20% to 87% yields (23 examples). The present method uses commercially available reagents, and can be performed on a ten gram-scale. Interestingly, methoxybenzene was cyanated in 32% yield in the absence of potassium ferricyanide, which suggests that the nitrile group of a part of the product is possibly from the solvent acetonitrile. [ABSTRACT FROM AUTHOR]

Abstract: In this paper, the interactions between cationic dyes and the ionic liquids (ILs) have been studied by 31P nuclear magnetic resonance (NMR), UV–Vis spectroscopy and conductometric measurements at different temperatures. It was shown that a decrease in the measured specific conductance of the (dye+IL) mixtures was caused by the formation of non-conducting or less conducting (dye+IL) associates. The associates were formed by 1:1 ratio of cation of the cationic dyes and anion of the ILs by using the 31P NMR and UV–Vis spectroscopy methods. The association constants were calculated by theoretical model based on the deviation from linear behavior, and the association constants were as high as 106 (L·mol−1)2. Thermodynamic results imply that the formation process of association was exothermic nature. It is expected that the associates reported here would have promising application as active materials for the preparation of ion-selective electrode used in the determination of ILs concentrations. [Copyright &y& Elsevier]

Abstract: Partition coefficients of amino acids, including glycine, alanine, 2-aminobutyric acid, valine, leucine, threonine, methinoine, tryptophan and tyrosine, in [C n mim]Br (n =4, 6, 8)+K2HPO4 aqueous two-phase systems (ATPSs) have been determined, and the relative hydrophobicity of the equilibrium phases in the ionic liquids-based aqueous two-phase systems has been characterized by the Gibbs energies of transfer for methylene group from the bottom salt-rich phase to the top ionic liquid-rich phase. Based on these results, factors affecting the partitioning behavior of the amino acids have been investigated. It is shown that partition coefficients of the amino acids increase with the increase of hydrophobicity of the amino acids and the ionic liquids, solution pH value, tie-line length of the ATPSs and temperature of the systems. The possible driving forces and the thermodynamic parameters for the partitioning of amino acids in the ionic liquids-based ATPSs have also been discussed. [Copyright &y& Elsevier]

Understanding the structure of ionic liquids under external electric field (EEF) is very important for their applications in many fields, such as cells, electrowetting and electrospray. An all-atom molecular dynamic simulation was performed under EEF for [C2MIM][BF4] in order to explore the structure and properties of ionic liquids. It is found that EEF can change the distribution from disorder to order and influence the shape of cations. We investigated the hydrogen bond further and found that the hydrogen bond network can be destroyed when EEF reaches a critical value (1.14 V/Å). Due to the order's arrangement of ions under EEF, it is found that the diffusion coefficient of solute in the direction of electric field is greatly enhanced. However, the ions are diffused slowly in the perpendicular direction to the electric field when EEF exceeds the critical value. [ABSTRACT FROM PUBLISHER]

Bi-based oxyhalide Bi4TaO8X (X=Cl, Br, I) photocatalysts have been prepared by the combined method of liquid phase and solid state reactions and characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and Ultraviolet-visible diffuse reflectance spectroscopy (UV-vis DRS). Using the azo dye wastewater simulated by aqueous methyl orange (MO) solutions, photocatalytic activity of these catalysts was studied under ultraviolet light, visual light, and solar irradiation. All of the samples had high photocatalytic activity. After 2 h of ultraviolet radiation, the degradation efficiency of methyl orange by Bi4TaO8X (X=Cl, Br, I) was as high as 100%. Under visible-light and solar irradiation, the photocatalytic activity decreased in the order Bi4TaO8I>Bi4TaO8Br>Bi4TaO8Cl. More than 90% degradation efficiency was observed for Bi4TaO8I after 12 h of solar irradiation. Furthermore, the photocatalytic degradation kinetics of methyl orange have been investigated under different types of light irradiation. [ABSTRACT FROM AUTHOR]

The recovery of wastewater proteins is gaining more attention in environmental protection. In the present work, phase diagram of the [Cnmim]X (n = 4, 6, 8; X = Cl and Br) + K2HPO4 aqueous two-phase systems have been determined, and the aqueous two-phase systems have been used to remove bovine serum albumin (BSA), lysozyme, and hemoglobin from the simulated wastewater. The influence of pH value, the composition of the aqueous two-phase systems, and the temperature of the systems on the partitioning of the proteins has been studied. It has been found that 76–100% of the proteins could be extracted into the ionic liquid-rich phase in a single step partition. The partition coefficients of lysozyme slightly increases but those of BSA and hemoglobin decrease with increasing tie line length (TLL). The higher extraction efficiency of the proteins is achieved at the pH value close to their isoelectric point and under higher temperatures. The results indicate that the IL-based aqueous two-phase systems have the potential for the separation of wastewater proteins. [ABSTRACT FROM AUTHOR]

Abstract: In this work, a novel Bi-based oxyhalide Bi4TaO8I was prepared and characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and UV–vis diffuse reflectance spectroscopy. Photocatalytic activity of this material was evaluated by using methyl orange (MO) as a representative azo dye. It was found that Bi4TaO8I had a visible light absorption, and the band-gap energy was estimated to be 2.43eV. This material exhibited good photocatalytic activity under both ultraviolet and visible light irradiation. The effects of initial MO concentration, aqueous pH, catalyst dosage and irradiation time on the photocatalytic activity were studied systematically. The photocatalytic degradation of MO by Bi4TaO8I under visible-light irradiation was found to follow the pseudo first-order reaction at the low initial concentrations of MO. Reuse of the catalyst was also examined, and the degradation efficiency of MO was still as high as 60% after 3cycles of 28h visible-light irradiation. Furthermore, it was found that the degradation of MO was also effective under solar irradiation. Five main degradation products were observed by HPLC/MS and their chemical structures were suggested. In order to exclude the photosensitization effect, the photocatalytic degradation efficiency of pentachlorophenol (PCP) by Bi4TaO8I was also determined under visible light irradiation. It is expected that Bi4TaO8I would have potential application in the degradation of azo dye wastewaters under solar irradiation. [Copyright &y& Elsevier]

Abstract: Alkylimidazolium salts are a very important class of ionic liquids (ILs). The ILs containing long alkyl chains are a kind of model surfactants. In this paper, the aggregation behavior of 1-decyl-3-methylimidazolium chloride ([C10mim]Cl) was investigated for the first time in aqueous monosaccharide (glucose, galactose, xylose and arabinose) solutions by conductivity, fluorescence, NMR and dynamic light scattering (DLS). Thus a series of physico-chemical parameters for the aggregation of [C10mim]Cl—the critical aggregation concentration (CAC), ionization degree of the aggregates (α), the standard Gibbs energy of aggregation (), and the aggregation number (N) were derived from the experimental data. The results show that addition of small amounts of monosaccharides in aqueous solution can cause a variation in aggregation properties of the IL. The CAC values decrease with increasing molality of monosaccharides. In particular for different kinds of monosaccharides, we found that the CAC values are in the order: glucose>galactose (hexoses), xylose>arabinose (pentoses); xylose>glucose (1e2e3e4e), arabinose>galactoses (1e2e3e4a). These trends may be attributed to the slight difference in the stereo-structure of monosaccharide molecules. Finally a mechanism for the interaction of these monosaccharides with [C10mim]Cl was proposed. [Copyright &y& Elsevier]

An efficient and sustainable synthesis of the otherwise difficult to obtain 1,3,4′-tricarbonyl compounds through a water mediated, TBAF·3H2O promoted unprecedented tandem reaction of 1,2-allenic ketone with α-halo ketone or α-halo ester has been developed. Remarkably enhanced reactivity and improved chemoselectivity by using water as the reaction medium was observed. The 1,3,4′-tricarbonyl compounds facilitate further versatile transformations, which underscores the importance of these products as synthetic intermediates. [ABSTRACT FROM AUTHOR]

Abstract: Densities, conductivities, and fluorescence spectra of {sodium dodecyl sulfate (SDS)+glutamine dipeptide+water} mixtures were measured as a function of temperature. The density data have been utilized to calculate apparent molar volumes, standard partial molar volumes (), standard partial molar volumes of transfer from water to aqueous SDS solutions (Δt V o), the hydration number, partial molar expansibility (), and Hepler’s constant of glutamine dipeptides. The critical micellar concentration (c cmc) and the degree of counterion dissociation of SDS micelles obtained from electrical conductivity data have been estimated at various concentrations of glutamine dipeptide. Thermodynamic parameters of micellization of SDS in aqueous dipeptide solutions have been determined from c cmc values and an enthalpy–entropy compensation effect was observed for the ternary systems. The pyrene fluorescence spectra were used to study the change of micropolarity produced by the interaction of SDS with glutamine dipeptide, and the aggregation behavior of SDS. The results have been interpreted in terms of solute–solvent interactions and structural changes in the mixed solutions. [Copyright &y& Elsevier]

Small AgPd ( n = 5) clusters and their hydrides AgPdH ( n = 5) have been studied by density functional theory calculations. For bare clusters, the structures in which the Pd atom has a maximum number of neighboring Ag atoms tend to be energetically favorable. Hydrogen prefers binding to AgPd bridge site of AgPd clusters except for AgPd. The binding energy has a strong odd-even oscillation. The electron transfers are from Ag atoms to Pd in bare clusters and are from metal clusters to H in cluster hydrides. © 2010 Wiley Periodicals, Inc. Int J Quantum Chem, 2011 [ABSTRACT FROM AUTHOR]

Abstract: The effect of glycyl dipeptides (glycylglycine, glycyl-L-valine, and glycyl-L-leucine) on the micellar properties of gemini surfactant pentamethylene-1,5-bis(dodecyldimethylammonium bromide) (12-5-12) has been investigated by means of conductivity and fluorescence spectroscopy. The results obtained from conductivity show that the effect of glycyl dipeptides depends upon their nature and concentration, as well as the temperature. The values of critical micelle concentration (cmc) of 12-5-12 have been estimated in water+glycyl dipeptide media at various concentrations of dipeptide in the 293.15–318.15K temperature range at 5K intervals. From cmc values, it is observed that the micellization tendency of the surfactant increases in the presence of glycyl dipeptides. Thermodynamic parameters (ΔG m o , ΔH m o , and ΔS m o ) of micellization of 12-5-12 in aqueous glycyl dipeptide solutions have been obtained by applying the mass action model and an enthalpy–entropy compensation effect was observed. The pyrene fluorescence spectra were used to study the change of micropolarity produced by the interaction of 12-5-12 with glycyl dipeptides, and the aggregation behavior of 12-5-12. [Copyright &y& Elsevier]

Abstract: A surface molecularly imprinted polymer (MIP) was synthesized by using imidazole as the template and modified silica particles as the support material. The static adsorption, solid phase extraction (SPE) and high-performance liquid chromatography (HPLC) experiments were performed to investigate the adsorption properties and selective recognition characteristics of the polymer for imidazole and its structural analogs. It was shown that the maximum binding capacities of imidazole on the MIP and the non-imprinted polymer (NIP) were 312 and 169μmolg−1, respectively. The adsorption was fast and the adsorption equilibrium was achieved in 30min. The binding process could be described by pseudo-second order kinetics. Compared with the corresponding non-imprinted polymer, the molecularly imprinted polymer exhibited much higher adsorption performance and selectivity for imidazole. The selective separation of imidazole from a mixture of 1-hexyl-3-methylimidazolium bromide ([C6mim][Br]) and 2,4-dichlorophenol could be achieved on the MIP–SPE column. The recoveries of imidazole and [C6mim][Br] were 97.6–102.7% and 12.2–17.3%, respectively, but 2,4-dichlorophenol could not be retained on the column. The surface molecularly imprinted polymer presented here may find useful application as a solid phase absorbent to separate trace imidazole in environmental water samples. This may also form the basis for our research program on the preparation and application of alkyl-imidazolium imprinted polymers. [Copyright &y& Elsevier]

Abstract: A combination of CuI (10mol%) and [bmim]OAc (20mol%) in [bmim]PF6 was found to be a highly efficient and readily recyclable catalytic system for the synthesis of 2,3-disubstituted benzo[b]furans via three-component tandem reactions of 2-hydroxybenzaldehydes, amines and alkynes. Remarkable advantages of this new strategy include high efficiency, convenient recovery and efficient reuse of the catalytic system. [Copyright &y& Elsevier]

In this work, ionic liquids/water distribution ratios (D) of azo dyes, including 1-(phenylazo)-2-naphthol, 1-(2-pyridylazo)-2-naphthol, 4-(nitrophenylazo)resorcinol, 4-(2-pyridylazo) resorcinol, and 2-(4-dimethylaminophenylazo) benzoic acid, have been determined experimentally. It was found that the D values are highly influenced by the pH of the water phase and the type of salts added. They increase with increasing alkyl chain length on the cations of the ionic liquids, and the anionic effect follows the order [BF4]- > [PF6]-. Possible extraction mechanism and selective separation of some azo dyes are also investigated. The results suggest that ionic liquids have potential applications in the removal and selective separation of azo dyes from water. [ABSTRACT FROM AUTHOR]

Abstract: The apparent molar volume (V 2,ϕ ) of glutamine dipeptides (glycyl-l-glutamine and l-alanyl-l-glutamine) and the molar conductivity (Λ) of sodium caproate (NaC6) have been determined from density and conductance measurements, respectively. The values of V 2,ϕ were utilized to deduce the standard partial molar volumes , standard partial molar volumes of transfer for glutamine dipeptides from water to aqueous sodium caproate solutions (Δt V o), hydration number (n H) and volumetric interaction coefficients. An increase in transfer volumes and a decrease in hydration numbers of the glutamine dipeptides with increasing sodium caproate concentration have been explained due to stronger interactions of sodium caproate with the charged center and polar groups of the glutamine dipeptides compared to the sodium caproate-nonpolar group of dipeptide interactions. From the molar conductivity of sodium caproate, the limiting molar conductivity of sodium caproate (Λ 0) and Walden products (Λ 0 η 0) were calculated. The decrease in Λ 0 and Walden products with increase in glutamine dipeptide concentration is attributed to the interactions of sodium caproate with glutamine dipeptides and the friction resistance of the solvent medium. Both the hydration number for glutamine dipeptides and Walden products values in peptide–sodium carboxylate–water systems are in the order: sodium acetate>sodium butyrate>sodium caproate. This can be ascribed to the fact that the interactions of dipeptides with sodium carboxylate increase with the increase in the size of side chain of carboxylate anions. [Copyright &y& Elsevier]

Abstract: A novel methodology for the synthesis of 2-benzoylbenzothiazoles and 2-benzylbenzothiazoles through FeCl3·6H2O catalyzed, air oxidized tandem process from commercially available 2-aminothiophenols and phenylacetaldehydes by using an ionic liquid as both reaction medium and co-catalyst was developed. [ABSTRACT FROM AUTHOR]

Abstract: As a new separation technology, ionic liquid (IL)-based aqueous two-phase systems (ATPSs) are attracting the attention of a growing number of scientists and engineers. This article reviews the significant progress that has been made in the field and highlights the possible directions of future developments. We focus on the effects of inorganic salts and ILs on the phase equilibrium of ATPSs, the microstructure of the ATPSs, and their applications in extraction and separation (e.g., small organic molecules, biochemicals, and radiological isotopes). We also address the recovery and the reuse of ILs and the work needed in future. [Copyright &y& Elsevier]

Abstract: Density functional theory calculations were carried out for CO binding on small Ag n Pd m clusters (n + m ⩽4). CO binds to Pd sites much stronger than Ag sites. Generally the CO binding energy increases with the Pd content increasing for the given cluster size. The binding site is the most sensitive factor to the C–O stretching frequency shifts. The binding energy correlates roughly with the magnitude of the metal–C–O frequency. Our calculation suggests that Ag n Pd m may react with CO dissociatively by ejecting Ag monomer or dimer. [Copyright &y& Elsevier]

Abstract: In this work, aggregation behavior of [C12mim]Br in acetonitrile, ethylene glycol, N,N-dimethylformamide, formamide and dimethylsulfoxide solvents was investigated by conductivity and volume measurements. The critical aggregation concentration CAC, degree of anion binding β, and the standard Gibbs energy of aggregation ΔG o have been derived from the experimental data. Solvophobic parameters have been introduced to account for the interaction between alkyl chain of the IL and the solvents. It is shown that solvophobic effect and the hydrogen-bonding interaction between the IL anion and the solvents are the main factors affecting the aggregation of ILs in non-aqueous solvents. The aggregation of ILs in non-aqueous solvents can be controlled and regulated by solvent properties. [ABSTRACT FROM AUTHOR]

Abstract: An efficient, practical and environmentally benign synthesis of 2-substituted benzothiazoles was developed through RuCl3-catalyzed oxidative condensation of 2-aminothiophenol with aldehyde in ionic liquid by using air as the oxidant. With this procedure, a series of 2-substituted benzothiazoles and benzothiazole/pyrimidine nucleoside hybrids with antimicrobial activities were efficiently prepared from easily accessible starting materials. [Copyright &y& Elsevier]