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A series of task-specific ionic liquids (TSILs) based on glycerylimidazolium cations have been prepared by reaction of 1-chloropropanediol, a compound obtainable from glycerol (a widely available and in-expensive waste product), with the appropriate base (1-H-imidazole, 1,2-dimethylimidazole and 1-methyl-1-H-imidazole). The reaction of 3-(1H-imidazol-1-yl)propane-1,2-diol with chloroalkanes, bromoalkanes and alkyl mesylates gave the corresponding salts which were characterized. The possibility to use these ILs in palladium catalyzed reactions was evaluated, evidencing good catalyst stability and a high recyclability. [ABSTRACT FROM AUTHOR]

Room temperature ionic liquids (ILs) are stable liquids composed of anions and cations. 1-ethyl-3-methyl-imidazolium (EMIm, EMI) is a popular and important cation that produces thermally stable ILs with various anions. In this study two amide-type anions, bis(trifluoro-methanesulfonyl)amide [N(SO2CF3)2, TFSA, TFSI, NTf2, or Tf2N] and bis(fluorosulfonyl)amide [(N(SO2F)2, FSA, or FSI] were investigated by multinuclear NMR spectroscopy. In addition to EMIm-TFSA and EMIm-FSA, lithium-salt-doped binary systems were prepared (EMIm-TFSA-Li and EMIm-FSA-Li). The spin-lattice relaxation times (T1) were measured by 1H, 19F, and 7Li NMR spectroscopy and the correlation times of 1H NMR, τc(EMIm) (8 × 10-10 to 3 × 10-11 s) for the librational molecular motion of EMIm and those of 7Li NMR, τc(Li) (5 × 10-9 to 2 × 10-10 s) for a lithium jump were evaluated in the temperature range between 253 and 353 K. We found that the bulk viscosity (η) versus τc(EMIm) and cation diffusion coefficient DEMIm versus the rate 1/τc(EMIm) have good relationships. Similarly, linear relations were obtained for the η versus τc(Li) and the lithium diffusion coefficient DLi versus the rate 1/τc(Li). The mean one-jump distances of Li were calculated from τc(Li) and DLi. The experimental values for the diffusion coefficients, ionic conductivity, viscosity, and density in our previous paper were analyzed by the Stokes-Einstein, Nernst-Einstein, and Stokes-Einstein-Debye equations for the neat and binary ILs to clarify the physicochemical properties and mobility of individual ions. The deviations from the classical equations are discussed. [ABSTRACT FROM AUTHOR]

Owing to their favorable properties, ionic liquids have recently gained recognition as possibly environmentally benign solvents. Now among the most promising industrial chemicals, they have already been labeled “green”, but this appellation seems due entirely to their very low vapor pressure. This growing interest in the various applications of ionic liquids will soon result in their presence in the environment. Therefore, reliable analytical tools for the environmental analysis of ionic liquids need to be developed urgently. This paper presents a newly developed analytical procedure for the enrichment of 1-alkyl- and 1-aryl-3-methylimidazolium ionic liquids from water samples. The method is based on cation exchange solid-phase extraction followed by selective elution. Pre-concentrated samples are subjected to high-performance liquid chromatography (HPLC) with an advanced methodology for qualitative and quantitative analysis. The overall procedure was verified by using standard spiked samples of tap water, seawater, and freshwater. [ABSTRACT FROM AUTHOR]

The present paper discusses the electrodeposition of nano-Aluminum using aromatic cation based ionic liquids. Three imidazolium chloride salts were employed, in ultrapure quality: l-ethyl-3-methyl-imidazolium chloride [EMIm]Cl, l-benzyl-3-methyl-imidazolium chloride [BzMIm]Cl and l,3-dibenzyl-imidazolium chloride [DBzIm]Cl, respectively. Anhydrous Aluminum chloride (AlCl 3 ) salt was used as a source of Aluminum ions in the ionic liquids. This research aims to achieve this goal by investigating the Aluminum coatings on gold substrate and study the effect of changing the organic cation on the properties of the resulting Al-coatings. SEM-EDAX analyses were used to determine the film composition. It was found that the particle size of the Al-deposites was dramatically reduced from the micrometer regime down to the nanometer regime with a change in the substituents of the imidazolium cations from EMIm to DBzIm, respectively. This means that the more the aromatic rings in the cation, the finer the particle size. Thickness and adhesion of the Al-deposits were decreased in the presence of the aromatic rings. [ABSTRACT FROM AUTHOR]

Description of the local microscopic structure in ionic liquids (ILs) is a prerequisite to obtain a comprehensive understanding of the influence of the nature of ions on the properties of ILs. The local structure is mainly determined by the spatial arrangement of the nearest neighboring ions. Therefore, the main interaction patterns in ILs, such as cation-anion H-bond-like motifs, cation-cation alkyl tail aggregation, and ring stacking, were considered within the framework of the nearest-neighbor approach with respect to each particular interaction site. We employed classical molecular dynamics (MD) simulations to study in detail the spatial, radial, and orientational relative distribution of ions in a set of imidazolium-based ILs, in which the 1-butyl-3-methylimidazolium (C4mim+) cation is coupled with the acetate (OAc-), chloride (Cl-), tetrafluoroborate (BF4 -), hexafluorophosphate (PF6 -), trifluoromethanesulfonate (TfO-), or bis(trifluoromethanesulfonyl)amide (TFSA-) anion. It was established that several structural properties are strongly anion-specific, while some can be treated as universally applicable to ILs, regardless of the nature of the anion. Namely, strongly basic anions, such as OAc- and Cl-, prefer to be located in the imidazolium ring plane next to the C-H2/4-5 sites. By contrast, the other four bulky and weakly coordinating anions tend to occupy positions above/below the plane. Similarly, the H-bond-like interactions involving the H² site are found to be particularly enhanced in comparison with the ones at H4-5 in the case of asymmetric and/or more basic anions (C4mimOAc, C4mimCl, C4mimTfO, and C4mimTFSA), in accordance with recent spectroscopic and theoretical findings. Other IL-specific details related to the multiple H-bond-like binding and cation stacking issues are also discussed in this paper. The secondary H-bonding of anions with the alkyl hydrogen atoms of cations as well as the cation-cation alkyl chain aggregation turned out to be poorly sensitive to the nature of the anion. [ABSTRACT FROM AUTHOR]

A range of ionic liquids containing dialkylimidazolium cations and halobismuthate anions ([BiBrxClyIz]- and [Bi2BrxClyIz]-) were synthesised by combining dialkylimidazolium halide ionic liquids with bismuth(III) halide salts. The majority were room temperature liquids, all with very high densities. The neat ionic liquids and their mixtures with 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide were characterised using Densitometry, Viscometry, NMR Spectroscopy, Electrospray Ionisation Mass Spectrometry (ESI), Liquid Secondary Ion Mass Spectrometry (LSIMS), Matrix-assisted Laser Desorption/Ionization Mass Spectrometry (MALDI), X-Ray Photoelectron Spectroscopy (XPS) and Thermogravimetric Analysis (TGA), to establish their speciation and suitability for high-temperature applications. [ABSTRACT FROM AUTHOR]

Supportedionic liquid membranes (SILMs) are promising tools for the separationof carbon dioxide from other gases. In this paper, new imidazolium,pyrrolidinium, piperidinium, and morpholinium ionic liquids with atriethylene glycol side chain and tosylate anions, as well as theirsymmetrical dicationic analogues, have been synthesized and incorporatedinto SILMs. The selectivities for CO2/N2andCO2/CH4separations have been measured. Theselectivities exhibited by the dicationic ionic liquids are up totwo times higher than the values of the corresponding monocationicionic liquids. Quantum chemical calculations have been used to investigatethe difference in the interaction of carbon dioxide with monocationicand dicationic ionic liquids. The reason for the increased gas separationselectivity of the dicationic ionic liquids is two-fold: (1) a decreasein permeance of nitrogen and methane through the ionic liquid layer,presumably due to their less favorable interactions with the gases,while the permeance of carbon dioxide is reduced much less; (2) anincrease in the number of interaction sites for the interactions withthe quadrupolar carbon dioxide molecules in the dicationic ionic liquids,compared to the monocationic analogues. [ABSTRACT FROM AUTHOR]

Relaxation processes for imidazolium-based ionic liquids (ILs) were investigated by means of an incoherent quasielastic neutron scattering technique. In order to clarify the cation and anion effects on the relaxation processes, ten samples were measured. For all of the samples, we found three relaxations at around 1 ps, 10 ps, and 100 ps-10 ns, each corresponding to the alkyl reorientation, the relaxation related to the imidazolium ring, and the ionic diffusion. The activation energy (Ea) for the alkyl relaxation is insensitive to both anion and alkyl chain lengths. On the other hand, for the imidazolium relaxation and the ionic diffusion processes, Ea increases as the anion size decreases but is almost independent of the alkyl chain length. This indicates that the ionic diffusion and imidazolium relaxation are governed by the Coulombic interaction between the core parts of the cations (imidazolium ring) and the anions. This is consistent with the fact that the imidazolium-based ILs have nanometer scale structures consisting of ionic and neutral (alkyl chain) domains. It is also found that there is a clear correlation between the ionic diffusion and viscosity, indicating that the ionic diffusion is mainly associated with the glass transition which is one of the characteristics of imidazolium-based ILs. [ABSTRACT FROM AUTHOR]

Owing to their ease of synthesis, diffuse positive charge, and chemical stability, 1‐alkyl‐3‐methylimidazolium cations (i.e. [Cnmim]+) are one of the most routinely utilized and historically important components in ionic liquid (IL) chemistry. However, while this is a routinely encountered member of the IL family as cations, relatively few workers have explored the versatile chemistry of azoles to allow their use as an anionic component in ILs, as azolates. Azolate anions possess many of the desired properties for IL formation, including a diffuse ionic charge, tailorable asymmetry, and synthetic flexibility, with the added advantages of not relying on halogen atoms for electron‐withdrawing effects, as is commonly encountered with IL anions such as hexafluorophosphate. This review explores the 122 azolate‐containing ILs known in the literature (prepared from only 39 disparate azolate anions), with a view to highlighting not only their demonstrated utility as an IL component, but the ways in which the larger scientific community may utilize their advantageous properties for new tailored materials. Overlooked but not forgotten! Versatile azolate anions as a promising ionic liquid component for new tailored materials. Azolate anions possess many of the desired properties for IL formation, including a diffuse ionic charge, tailorable asymmetry, and synthetic flexibility. [ABSTRACT FROM AUTHOR]

Liquid-liquid extraction of Eu3+ from aqueous solution with 4-oxaheptanediamides (OHAs) as extractant into room temperature ionic liquids (RTILs) of 1-alkyl-3-methylimidazolium hexafluorophosphate (Cnmim+PF6-, n = 4, 6 and 8) was investigated. The strong affinity of OHAs to Eu3+ was observed in the present Cnmim+PF6- system. The extraction was assumed to proceed by cation-exchange mechanism and formed a 4:1 complex of the OHA extractants and Eu3+ in C4mim+PF6- system. The preferable composition of extracted species was presumed to be Eu(OHA)4(H2O)4(PF6)3 by ESI-MS. [ABSTRACT FROM AUTHOR]

Ionic liquids with imidazolium as cation are usually synthesized with different types of imidazolium cations, substituents, and anions. This review mainly focuses on of imidazolium-based ionic liquids in the field of modifying functional materials applied on separation of active compounds, especially on chromatographic separations ((high performance liquid chromatography (HPLC) and gas chromatograph (GC)) using materials based on imidazolium functionality as stationary phase. In addition, the preparation, classification, and physicochemical properties of various types of imidazolium-based ionic liquids are described. Although further studies are still much required, applications of imidazolium-based ionic liquids processes has made great progress in recent years and provided a new perspective in many fields. The problems associated with the industrial use of imidazolium-based ionic liquids are still required to further dealt with. [ABSTRACT FROM AUTHOR]

This article describes a pioneering ion-pair chromatography with indirect ultraviolet detection with imidazolium ionic liquids (ILs) as ultraviolet absorption reagent and eluting agent for determination of pyrrolidinium cations. Three pyrrolidinium cations were analyzed on a reversed-phase silica-based monolithic column by isocratic elution with imidazolium ILs-ion-pair reagents-methanol mixtures. The effects of the ultraviolet absorption reagents, detection wavelength, ion-pair reagents, imidazolium ILs, organic solvents, column temperature and flow rate on the separation and determination of pyrrolidinium cations were investigated. Under the selected chromatographic conditions, the separation time was reduced to <2.5min while maintaining excellent peak shapes and sufficient resolution. The detection limits for N-methyl-N-ethylpyrrolidinium cation, N-methyl-N-propylpyrrolidinium cation and N-methyl-N-butylpyrrolidinium cation were 0.12, 0.08 and 0.19mg/L, respectively. Relative standard deviations for peak area were <0.59%. This simple and practical method has been successfully applied to the determination of three IL samples synthesized by the chemistry laboratory. The method is accurate, reliable and meets the requirements for quantitative analysis. In general, the analytical system and its associated methods appear to be widely applicable to determination of pyrrolidinium cations. [ABSTRACT FROM AUTHOR]

We report the very first application of a Transient 1D 1H{19F} NOE NMR experiment in neat ionic liquids. In comparison with classical 2D HOESY NMR spectroscopy, a substantial reduction in measurement time is gained with comparable quality and information content of the spectra. In combination with classical X‐ray crystallography, we have applied this technique for the determination of inter‐ionic distances (i.e. probabilities of presence) utilizing an ionic liquid containing a monofluorinated imidazolium cation. Copyright © 2017 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Magnetic carbon nanotube-supported imidazolium ionic liquid (CNT-Fe3O4-IL) was synthesized and investigated using various characterization techniques, including Fourier transform infrared and Raman spectroscopies, X-ray diffraction, vibrating sample magnetometry, scanning and transmission electron microscopies, and thermogravimetric and differential thermal analyses. In order to synthesize the CNT-Fe3O4-IL nanocomposites, Fe3O4-decorated multi-walled CNTs were modified with 1-methyl-3-(3-trimethoxysilylpropyl)-1 H-imidazol-3-ium chloride. This catalytic system was found to be a highly stable, active, reusable and solid-phase catalyst for the synthesis of 2-aminothiazoles via the of ketone, thiourea and N-bromosuccinimide under mild conditions. Immobilized magnetic ionic liquid combines the advantages of ionic liquid media with magnetic solid support nanomaterials which enables the application of nanotechnology and in chemical processes. Copyright © 2016 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Polystyrene-supported 1,4-bis(3-methylimidazolium-1-yl)butane dihydroxide basic dicationic ionic liquid was prepared by supporting the ionic liquid onto highly cross-linked chloromethylated polystyrene. FT-IR, SEM, TG-DTA, and elemental analysis were employed to characterize the structure and property of the catalyst. The results suggested that our basic dicationic ionic liquid was supported on the surface of PS-CHCl by a covalent bond. This basic dicationic ionic liquid exhibited high catalytic activity for the one-pot synthesis of chromene derivatives in water. The unique features of the catalyst, such as high thermal stability, recyclability, excellent catalytic activity in terms of yield and reaction time, high turnover number and turnover frequency, and also using water as a solvent, would be potentially important for its applications in industry. [ABSTRACT FROM AUTHOR]

Branching at the alkyl side chain of the imidazolium cation in ionic liquids (ILs) was evaluated towards its effect on carbon dioxide (CO2) solubilization at 10 and 80 bar (1 bar=1×105 Pa). By combining high-pressure NMR spectroscopy measurements with molecular dynamics simulations, a full description of the molecular interactions that take place in the IL-CO2 mixtures can be obtained. The introduction of a methyl group has a significant effect on CO2 solubility in comparison with linear or fluorinated analogues. The differences in CO2 solubility arise from differences in liquid organization caused by structural changes in the cation. ILs with branched cations have similar short-range cation-anion orientations as those in ILs with linear side chains, but present differences in the long-range order. The introduction of CO2 does not cause perturbations in the former and benefits from the differences in the latter. Branching at the cation results in sponge-like ILs with enhanced capabilities for CO2 capture. [ABSTRACT FROM AUTHOR]

By means of Raman spectroscopy coupled with density functional theory (DFT) calculations and perturbation correlation moving window two-dimensional correlation spectroscopy intermolecular interactions were assessed in mixtures of ionic liquid (IL) 1- n-butyl-3-methylimidazolium hexafluorophosphate (BmimPF6) with polar aprotic solvent γ-butyrolactone (γ-BL) over the entire range of compositions. The symmetrical P-F stretching vibration of the IL anion was found to be insensitive to the changes in mixture concentration in contrast to the CO stretching vibration of the γ-BL and the imidazolium ring C-H stretching vibrations of the IL cation. Each of these vibrational profiles was decomposed in various spectral contributions, and their number was rationalized by the results of quantum-chemical calculations and/or previous controversial published data. Progressive redshift of the ring C-H stretching wavenumbers was referred to pronounced solvation of the cation at the imidazolium ring site accompanied with H-bond formation. This was especially pronounced at IL mole fraction less than 0.18. Complicated variations in the intensities of the individual contributions of the CO profile were treated as a manifestation of the changing with concentration pattern of the intermolecular interactions. The self-association of γ-BL molecules and distinct cation solvation as dominant intermolecular interactions at low IL content are replaced with weaker cation solvation and ion association at high concentrations of IL. Possible representative molecular structures were proposed on the basis of DFT calculations. Copyright © 2015 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

New salts based on imidazolium, pyrrolidinium, phosphonium, guanidinium, and ammonium cations together with the 5-cyanotetrazolide anion [C2N5]− are reported. Depending on the nature of cation-anion interactions, characterized by XRD, the ionic liquids (ILs) have a low viscosity and are liquid at room temperature or have higher melting temperatures. Thermogravimetric analysis, cyclic voltammetry, viscosimetry, and impedance spectroscopy display a thermal stability up to 230 °C, an electrochemical window of 4.5 V, a viscosity of 25 mPa s at 20 °C, and an ionic conductivity of 5.4 mS cm−1 at 20 °C for the IL 1-butyl-1-methylpyrrolidinium 5-cyanotetrazolide [BMPyr][C2N5]. On the basis of these results, the synthesized compounds are promising electrolytes for lithium-ion batteries. [ABSTRACT FROM AUTHOR]

The terahertz and infrared frequency vibration modes of room-temperature ionic liquids with imidazolium cations and halogen anions were extensively investigated. There is an intermolecular vibrational mode between the imidazolium ring of an imidazolium cation, a halogen atomic anion with a large absorption coefficient and a broad bandwidth in the low THz frequency region (13–130 cm–1), the intramolecular vibrational modes of the alkyl-chain part of an imidazolium cation with a relatively small absorption coefficient in the mid THz frequency region (130–500 cm–1), the intramolecular skeletal vibrational modes of an imidazolium ring affected by the interaction between the imidazolium ring, and a halogen anion with a relatively large absorption coefficient in a high THz frequency region (500–670 cm–1). Interesting spectroscopic features on the interaction between imidazolium cations and halogen anions was also obtained from spectroscopic studies at IR frequencies (550–3300 cm–1). As far as the frequency of the intermolecular vibrational mode is concerned, we found the significance of the reduced mass in determining the intermolecular vibration frequency. [ABSTRACT FROM AUTHOR]

In this work, synthetic layered silicates denoted Somasif ME-100 and Laponite® RD were modified with dialkyl imidazolium and alkyl phosphonium ionic liquids by cationic exchange reaction. In both cases, the phosphonium (P-ME, P-RD) or imidazolium ion (I-ME, I-RD)-treated micas and laponites display an excellent thermal stability compared to commonly used quaternary ammonium salts. To highlight the effect of these ionic liquids, the modified layered silicates were introduced in a high density polyethylene (HDPE). Thus, polyethylene nanocomposites filled with a low amount of nanoparticles (2 wt%) were prepared by twin screw extrusion. Then, transmission electronic microscopy (TEM) analysis has been used to investigate the effect of ILs on the different morphologies of these nanocomposites. In addition, the use or not of compatibilizer such as PEgMA (20% by weight) has been also studied on the mechanical behaviour of these polymer nanocomposites. Even though the thermal stability of polyethylene matrix remains unchanged, a good stiffness-thoughness compromise has been observed. [ABSTRACT FROM AUTHOR]

Thirty six novel ionic liquids (ILs) with 1-butyl-3-methylimidazolium and 3-methyl-1-octylimidazolium cations paired with 2-substitited 4,5-dicyanoimidazolate anions (substituent at C2=chloro, bromo, methoxy, vinyl, amino, methyl, ethyl, propyl, isopropyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl and phenyl) have been synthesized and characterized by using differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and single-crystal X-ray crystallography. The effects of cation and anion type and structure on the thermal properties of the resulting ionic liquids, including several room temperature ionic liquids (RTILs) are examined and discussed. ILs exhibited large liquid and crystallization ranges and formed glasses on cooling with glass transition temperatures in the range of −22 to −68 °C. The effects of alkyl substituents of the imidazolate anion reflected the crystallization, melting points and thermal decomposition of the ILs. The Coulombic packing force, van der Waals forces and size of the anions can be considered for altering the thermal transitions. Three crystal structures of the ILs were determined and the effects of changes to the cations and anions on the packing of the structure were investigated. [ABSTRACT FROM AUTHOR]

The electrochemical behavior and thermodynamic properties of Ln(III) (Ln = Eu, Sm, Dy, Nd) were studied in 1-butyl-3-methylimidazolium bromide ionic liquid (BmimBr) at a glassy carbon (GC) electrode in the range of 293–338 K. The electrode reaction of Eu(III) was found to be quasi-reversible by the cyclic voltammetry, the reactions of the other three lanthanide ions were regarded as irreversible systems. An increase of the current intensity was obtained with the temperature increase. At 293 K, the cathodic peak potentials of −0.893 V (Eu(III)), −0.596 V (Sm(III)), −0.637 V (Dy(III)) and −0.641 V (Nd(III)) were found, respectively, to be assigned to the reduction of Ln(III) to Ln(II). The diffusion coefficients (Do), the transfer coefficients (α) of Ln(III) (Ln = Eu, Sm, Dy, Nd) and the charge transfer rate constants (ks) of Eu(III) were estimated. The apparent standard potential (E0*) and the thermodynamic properties of the reduction of Eu(III) to Eu(II) were also investigated. [ABSTRACT FROM AUTHOR]

The charge scaling effect in ionic liquids was explored on the basis of experimental and theoretical charge-density analyses of [C1MIM][C1SO4] employing the quantum theory of atoms in molecules (QTAIM) approach. Integrated QTAIM charges of the experimental (calculated) charge density of the cation and anion resulted in non-integer values of ±0.90 (±0.87) e. Efficient charge transfer along the bond paths of the hydrogen bonds between the imidazolium ring and the anion was considered as the origin of these reduced charges. In addition, a detailed QTAIM analysis of the bonding situation in the [C1SO4]− anion revealed the presence of negative πO→σ*S-O hyperconjugation. [ABSTRACT FROM AUTHOR]

The influence of the length of the cation alkyl chain on the dispersibility by ultrasonic treatment of TiO nanopowders in hydrophilic imidazolium-based room temperature ionic liquids was studied for the first time by dynamic light scattering and advanced rheology. TiO nanopowders had been synthesized by chemical vapor synthesis (CVS) under varied conditions leading to two different materials. A commercial nanopowder had been used for comparison. Characterizations had been done using transmission electron microscopy, X-ray diffraction, nitrogen adsorption with BET analysis, and FT-IR spectroscopy. Primary particle sizes were about 6 and 8 nm for the CVS-based and 26 nm for the commercial materials. The particle size distribution in the dispersion was strongly influenced by the length of the cation alkyl chain for all the investigated powders with different structural characteristics and concentrations in the dispersion. It was found that an increase of the alkyl chain length was beneficial, leading to a narrowing of the particle size distribution and a decrease of the agglomerate size in dispersion. The smallest average nanoparticle sizes in dispersion were around 30 nm. Additionally, the surface functionality of the nanoparticles, the concentration of the solid material in the liquid, and the period of ultrasonic treatment control the dispersion quality, especially in the case of the ionic liquids with the shorter alkyl chain. The influence of the nanopowders characteristics on their dispersibility decreases considerably with increasing cation alkyl chain length. The results indicate that ionic liquids with adapted structure are candidates as absorber media for nanoparticles synthesized in gas phase processes to obtain liquid dispersions directly without redispergation. [ABSTRACT FROM AUTHOR]

Following the development in the synthesis of subvalent cluster compounds, we report on the use of three different classes of room-temperature ionic liquids for the synthesis of the pentabismuth-tris(tetragallate) salt, Bi[GaCl], characterized by X-ray diffraction. The Bi[GaCl] salt was prepared by reduction of BiCl using gallium metal in ionic liquid reaction media containing a strong Lewis acid, GaCl. The ionic liquids; trihexyltetradecyl phosphonium chloride [Th-Td-P]Cl, 1-dodecyl-3-methylimidazolium chloride [Dod-Me-Im]Cl and N-butyl- N-methylpyrrolidinium chloride [Bu-Me-Pyrr]Cl from three of the main classes of ionic liquids were used in synthesis. Reactions using ionic liquids composed of the trihexyltetradecyl phosphonium cation [Th-Td-P] and the anions; tetrafluoroborate [BF], bis(trifluoro-methyl sulfonyl) imide [(Tf)N] and hexafluorophosphate [PF] were also investigated. [ABSTRACT FROM AUTHOR]

A series of hydroxy I-functionalized imidazolium bis (trifluoromethylsulfonyl) imide ionic liquids (ILs) with alkyl chain lengths ranging from CI to C10 were successfully synthesized and systematically investigated as lubricants for steel-steel contacts at room temperature and three different lu-bricating conditions. The effect of either hydroxy ethyl group or alkyl chain length on physicochemical and tribological prop-erties of the ILs was discussed at length, and the optimum chemical structure was also obtained. It was found that in-corporation of a hydroxyethyl group to the imidazolin cation had a great impact on thermal stability, frictionai coefficient, and wear but less impact on viscosity and corrosivity. It is also found that increasing alkyl chain length in the imidazolin cation had a significant influence on corrosion, the frictionai coefficient, and wear but the effect dropped rapidly from CI to C6 and progressively recovered as it increased from C6 to C10. To a much lesser extent, a similar effect was seen on thermal stability. As expected, increasing alkyl chain length monotonically increased viscosity. Furthermore, the lubrica-tion mechanism in the friction process was explored in depth by means of scanning electron microscopy (SEM) and X-ray photoelectron spectrometry (XPS), and a proposed inter-action model between the ILs and the friction surfaces was provided. [ABSTRACT FROM AUTHOR]

For the first time, the anodic behavior of platinum and titanium in ionic liquids (ILs) based on the imidazolium cation was investigated. ILs were established to possess a set of advantages compared with the traditional sulfuric acid electrolytes. It isn't necessary to maintain both a particular temperature and to use environmentally-harmful reagents, such as methanol or hydrofluoric acid, when electropolishing metals in IL media. The addition of propylene glycol to BMImCl (1 : 1) results in the formation of layers of titanium dioxide nanotubes on the metal surface. [ABSTRACT FROM AUTHOR]

This work aims at identifying, amongst extreme soil biotypes at locations of high salinity and high hydrocarbon load, microbial strains able to survive short or long-term exposure to the presence of selected ionic liquids. We have evaluated the impact of ionic liquids on the diversity of the soil microbiota to identify which microbial strains have higher survival rates towards ionic liquids, and consequently those which might possibly play a major role in their biotic fate. To the best of our knowledge, this is the first study of this kind. Soils, from a region in Portugal (Aveiro) were sampled and the bacterial and fungal strains able to survive after exposure to high concentrations of selected ionic liquids were isolated and further characterised. We have mainly focused on two types of cations: imidazolium – the most commonly used; and cholinium – generally perceived as benign. The surviving microbial strains were isolated and taxonomically identified, and the ionic liquid degradation was analysed during their cultivation. The continuing exposure of the microbial strains to petroleum hydrocarbons is likely to be the basis for their acquired resistance to some imidazolium salts; also, the higher capacity of fungi – compared to bacteria – to grow, even during their exposure to these liquid salts, became evident in this study. [ABSTRACT FROM AUTHOR]