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Naphthenic acid is a toxic component that is present in the crude oil. It causes severe operational problems for oil refineries. However, naphthenic acid is a useful raw material for many industrial processes. Thus, it is advantageous to extract and recover the naphthenic acid from crude oil. Ionic liquid has been considered as an environmental friendly material that can be used to extract naphthenic acid from crude oil. However, the characteristics of the ionic liquids to achieve the best extraction efficiency is still not completely known. In this research, the performance of the ionic liquids consists of diazabicyclo undecene (DBU) based cations and dicyanamide (DCN) anion in the extraction of naphthenic acid from acidic model oil was studied. Computer simulation of a mixture of naphthenic acid, ionic liquid, and n-dodecane was also performed. The study showed that the DBU-DCN based ionic liquids can effectively extract naphthenic acid from highly acidic model oil. The increase in the alkyl chain length on the cation increases the percent naphthenic acid extraction. Molecular simulation studies showed that the dicynamide anion interacting directly with the naphthenic acid. The alkyl chain on the DBU cation does not form any cage around the naphthenic acid as previously proposed. The study suggests that the biggest factor affecting naphthenic acid extraction efficiency is the extent of solubility of the polar ionic liquid in the non-polar oil.

Readily biodegradable and “practically non-toxic” dual functionalized imidazolium ionic liquids (ILs) carrying nitrile and varying number of ether group were developed to improve the extractive desulfurization performance and ecotoxicity of ILs. Dicyanamide (N(CN)2), trifluoroacetate (CF3COO) and bis(trifluoromethylsulfonyl)imide (NTf2) were selected as anions. Evaluation of thermophysical properties of the synthesized ILs revealed that bis(trifluoromethylsulfonyl)imide anion based ILs have lowest viscosity, which contributed to excellent mass transfer and enhanced desulfurization performance. The effect of temperature, time and mass ratio (ILs: model oil) were investigated for extractive desulfurization and the performance of ILs were in the anion order; dicyanamide

A computational screening strategy applied to 8 million synthetically diverse ionic liquids, demonstrates its value for sustainable solvent design. In contrast to previous studies which have largely focused on single characteristics, important properties such as viscosity, density, thermal stability and toxicity, were estimated using machine learning. Experimental characterization of 15 compounds selected from the library reinforced the utility of the approach. Over 2600 ionic liquids, a majority of which have never been reported before, were investigated for applications in CO2 and H2S gas separation, and cellulose dissolution, using density functional theory calculations. Among these, around 250 low cytotoxicity and low viscosity ionic liquids merit further investigation.

The adsorption of a dye to a metal oxide surface such as TiO2, NiO and ZnO leads to deprotonation and often undesirable aggregation of dye molecules, which in turn impacts the photophysical properties of the dye. While controlled aggregation is useful for some applications, it can result in lower performance for dye-sensitized solar cells. To understand this phenomenon better, we have conducted an extensive search of the literature and identified over 4000 records of absorption spectra in solution and after adsorption onto metal oxide. The total data set comprises over 3500 unique compounds, with observed absorption maxima in solution and after adsorption on the semiconductor electrode. This data may serve to provide further insight into the structure-property relationships governing dye-aggregation behaviour. This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

A series of 36 dual functionalized N-(poly)ethylen glycol N-allyl-/N-benzyl imidazolium and benzimidazolium ILs were synthesized for extractive desulfurization studies (EDS). The novel ILs were readily prepared from imidazole by a three-step dialkylation and anion exchange procedure and characterised (1H, 13C, 19F NMR; IR; HRMS positive/negative mode). The desulfurization studies were performed on a model oil with dibenzothiophene (DBT) and 4,6-dimethyldibenzothiophene (4,6-DMDBT) in n-dodecane. The N-allyl benzimidazolium based ILs exhibited higher extraction efficiency than corresponding imidazolium-based ILs (69 vs 59% DBT; 52 vs 29% 4,6-DMDBT). The EDS efficiency of the prepared ILs varied with the N-ethylen glycol chains length and by N-allyl or N-benzyl substitution on the imidazolium ILs. The results indicated that desulfurization efficiency is mainly affected by variation of the IL cation, as the IL anions (NTf2; N(CN)2-, SCN-, BF4-) only had minor impact on the extraction capacity of sulfur compounds. 1H NMR studies of IL-DBT solutions illustrated different EDS mechanisms, and specific interactions could explain the higher desulfurization capacity of dual functionalized benzimidazolium than the corresponding imidazolium ILs. 1H NMR confirmed that stronger π-π interactions between the planar aromatic electron system of benzimidazolium ILs and aromatic dibenzothiophenes play a major role for the high EDS extraction efficiency. © 2020 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/BY/4.0/).

Protic ionic liquids (ILs) with seven-membered azepanium cation were synthesized and characterized. The molecular structure of the synthesized ILs was confirmed using 1H NMR and 13C NMR spectroscopy. In one hand, sulfonic acid ( SO3H) group was tethered to the azepanium moiety combined with HSPO4 or H2PO4−anion and on the other hand azepanium based alkyl sulfate ILs were synthesized by reacting azepane with corresponding dialkyl sulfates. Thermo-physical properties (density, viscosity, glass transition temperature, thermal decomposition temperature) of the synthesized ILs were measured. All the studied ILs showed good thermal stability. From the viscosity and density data of alkyl sulfate ILs, the volumetric properties such as molar volume, lattice energy and standard molar entropy were calculated. COSMO-RS was used to predict hydrogen bonding energy, interaction energy, Van der Waals energy and H-bond accepting and H-bond donating nature of these pure ILs. Activity coefficient values have also predicted for these ILs with cellulose.

Ionic liquids (ILs) have seen increasing use as environmentally friendly solvents in a wide array of applications from energy to pharmaceuticals. Among the many properties of interest, the refractive index, is of considerable importance since several related properties can be estimated once the refractive index of a material is known. Furthermore, high refractive index ILs are also used as reference solutions to determine properties of optical materials. However, with a large collection of cation-anion combinations to choose from, the task of finding suitable ionic liquids is far from trivial. In this article, machine learning models have been used to estimate the temperature-dependent refractive index over 450 diverse ILs using cheap to compute semi-empirically derived structure descriptors. In addition to using independent test sets for evaluating the predictive ability of the models, the efficacy of the models was further evaluated using 14 new ionic liquids that were synthesized. Overall, ensemble decision tree-based approaches gave the best results with mean absolute errors < 0.01 and squared correlations > 0.85 across both calibration and test data.

In this study, imidazolium based ionic liquids with different functional group were chemically tethered to silica support and resulted in silica supported solid ionic liquids phases (SILPs). The SILPS were characterized using CHNS elemental analysis, Fourier Transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM) and thermo gravimetric analysis (TGA). The adsorption of commercial naphthenic acid from dodecane/kerosene was performed using SILPs. It was observed that their adsorption efficiency varied depending on the functional group on the imidazolium cation. This study was also modeled using COSMO-RS. The SILPs are efficient adsorbent in the extraction of naphthenic acid from highly acidic model oil. The recovery of adsorbed naphthenic acids from the SILPs was also investigated.

A series of ester functionalized imidazolium ionic liquids (ILs) with varying alkyl chain length were synthesized and characterized. Dicyanamide was chosen as the anion for these series of ILs. NMR (1H and 13C) and elemental analysis were used to confirm the structure of ILs. Thermal analysis (TGA) revealed that the synthesized ILs have good thermal stability up to 180 °C. The ILs were screened by COSMO-RS to further investigate their σ surface, σ potential and σ profile to obtain better understanding on the nature of interaction of ILs with sulfur compounds. The effect of temperature, time and mass ratio (ILs: model oil) were studied for the extraction of dibenzothiophene (DBT) from model oil using the synthesized ILs. The extractive desulfurization of model oil containing DBT in n-dodecane revealed that the ester functionalized ILs with an alkyl length of six carbon atoms, [C2COOCH3ImC6H13][N(CN)2] is the most promising candidate. More than 80% of DBT was extracted in 15 min with a mass ratio (ILs: model oil) of 2:1 at 25 °C. This high efficiency was observed in a single stage extraction, which indicated that the ester based ILs are an ideal candidate for the removal of DBT in a short extraction period. The ILs had good reusability up to 10 cycles with high extraction efficiency. The toxicity profile of ILs were assessed to evaluate their impact on environment and living organisms. Microbial toxicity studies depicted that the ILs can be considered as “practically harmless”.

Synthesis of new dual functionalized imidazolium ionic liquids (ILs) containing nitrile functionality and ether group were synthesized and characterized. Bis(trifluoromethylsulfonyl)imide, trifluoroacetate and dicyanamide were used as the anion. The combination of two functional groups on an imidazolium cation was mainly developed to assess their potential in desulfurization of fuel oil. Although ILs based on this individual functional group has been reported to improve the desulfurization efficiency, no effort has been made to combine nitrile and ether functional groups on the same cation to enhance the desulphurization potential. In this report, we tailored both nitrile and ether functionality on imidazolium cation and studied their physicochemical properties in details. NMR ( 1 H and 13 C) spectroscopy and elemental analysis were used to characterize the synthesized ILs. Physical properties and optical properties of the ILs were investigated in a wide temperature range. The synthesized ILs showed good thermal stability. COSMO-RS was effectively utilized to discuss the σ surface, σ potential and σ profile of the synthesized ILs.

Alkaline ionic liquids (ILs) with unconventional organic anions were prepared and used for cellulose dissolution studies. High concentrations of cellulose were dissolved at room temperature in the phenolate based imidazolium IL [C2mim][OPh], combined with organic solvent, and up to 45 wt-% cellulose dissolution (wt-% MCC of weight IL) was readily achieved at 100 oC. No functionalization of the regenerated cellulose was observed during the dissolution process (FTIR). Characteristic cellulose II XRD diffraction pattern was observed after IL dissolution and regeneration of MCC. The crystallinity index (CI) of the pretreated MCC was reduced from 93.2 % to 31 %. Inert conditions were not required for the cellulose dissolution experiments. This study indicates that the IL H-bond basicity is not the only key parameter determining their cellulose dissolution ability. The alkaline ILs represent an energy efficient and sustainable approach for cellulose dissolution.

Advancements in lithium-ion battery (LIB) technologies for e-mobility in terms of characteristic improvements and declining costs are proving to be beneficial for their application for both utility-scale and small-scale stationary energy storage. However, LIBs face challenges related to perceived future supply–demand mis-match of critical raw materials such as cobalt and lithium, and general safety and cost factors, particularly for off-grid markets. Rechargeable magnesium batteries (RMBs) are promising alternative for LIBs for stationary energy storage applications owing to their superior volumetric capacity, abundance and the low cost of magnesium metal. Nevertheless, the progress of RMBs is critically limited by the materials (anode, electrolyte, cathode, current collector) challenges. The formation of a non-ion conducting layer on the magnesium metal with conventional electrolytes during cycling is one such challenge that severely affects the development of RMB technology. This chapter presents a literature-based review on the research of the development of various types of anode materials such as Mg nanostructures, Mg intermetallic alloys and insertion-type materials for RMBs.

Ionic liquids have a broad spectrum of applications ranging from gas separation to sensors and pharmaceuticals. Rational selection of the constituent ions is key to achieving tailor-made materials with functional properties. To facilitate the discovery of new ionic liquids for sustainable applications, we have created a virtual library of over 8 million synthetically feasible ionic liquids. Each structure has been evaluated for their-task suitability using data-driven statistical models calculated for 12 highly relevant properties: melting point, thermal decomposition, glass transition, heat capacity, viscosity, density, cytotoxicity, CO 2 solubility, surface tension, and electrical and thermal conductivity. For comparison, values of six properties computed using quantum chemistry based equilibrium thermodynamics COSMO-RS methods are also provided. We believe the data set will be useful for future efforts directed towards targeted synthesis and optimization. © 2019 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).

Research on Ionic Liquids (ILs) recently focuses on investigating the properties of ILs salt-solvent mixtures (SSMs). The SSMs gained an unprecedented popularity because it offers wide range of properties necessary for the desired applications. In this work, imidazolium ILs containing nitrile and varying number of ether group coupled with bis(trifluoromethanesulfonyl)imide anion were synthesized. These ILs were mixed with dimethylsulfoxide (DMSO) in various mole ratio to form a salt-solvent mixtures. Density, dynamic viscosity and electrical properties of pure ILs and its mixtures were investigated over a wide temperature range. Thermodynamic properties such as thermal coefficient of expansion, standard entropy and lattice energy of pure ILs increased when the number of ether group on the cation side chain increased. Dynamic viscosities and electrical conductivity of the SSMs were investigated over a wide temperature range and different mole ratio, described by Vogel–Fulcher–Tamman (VFT) equation and Arrhenius equation. The relationship between dynamic viscosity and electrical conductivity was illustrated by Walden's Rule and it revealed that the SSM's have high conductivities at low fluidity, which can be categorized as ‘super ionic liquids’. Electrochemical potential window (EPW) and conductivity results for the SSMs revealed their (Mole ratio ILs =0.8) excellent potential in electrochemical applications.

The synthesis of nitrile-functionalized azepanium ionic liquids such as 1-butyl-1-(2-cyano-ethyl)-azepanium bromide, [C4CNAzp][Br], 1-butyl-1-(2-cyano-ethyl)azepanium trifluoroacetate, [C4CNAzp][TFA], 1-butyl-1-(2-cyano-ethyl)-azepanium methanesulfonate [C4CNAzp][CH3SO3], 1-butyl-1-(2-cyano-ethyl)azepanium trifluoromethanesulfonate [C4CNAzp][CF3SO3], 1-butyl-1-(2-cyano-ethyl)azepaniummethanesulfate[C4CNAzp][CH3SO4],1-butyl-1-(2-cyano-ethyl) azepanium p-toluenesulfonate [C4CNAzp][PTS] were performed. The synthesis of ionic liquids was performed in three steps. 1H, 13C and CHNS elemental analysis were used to characterize the synthesized ionic liquids. The thermal stability, melting point and glass transition temperature of the ionic liquids were determined. The nitrile-functionalized ionic liquids showed good thermal stability.

Superiority of silica supported ionic liquids over other adsorbents in capturing elemental mercury (Hg0) from flue gases has been recently reported. In this study, activated carbon, which is more economical than silica, was experimented as a solid support for ionic liquids (ILs) for gaseous Hg0 removal. Four ILs were successfully coated on activated carbon. The carbon supported ionic liquids (CSILs) were characterized by Fourier transform infrared spectroscopy, Brunauer–Emmett–Teller surface area analysis, field emission scanning electron microscopy, energy-dispersive X-ray, X ray-photoelectron spectroscopy and nuclear magnetic resonance. A continuous fixed bed flow reactor was used to examine the performance of CSILs in treating 20–35 ppm Hg0 vapor at a gas flow rate of 60 mL/min. 1-Butyl-3-methylimidazolium chloride [Bmim]Cl coated activated carbon was the most reactive among CSILs studied and a powdered form of [Bmim]Cl coated activated carbon was able to uptake Hg0 up to 23 mg/g and 60 mg/g with N2 and CH4 as carrier gas, respectively. A molecular simulation was performed to investigate the molecular level interaction between the Hg0 and the ILs to understand the effect of structural variations of the ILs on Hg0 adsorption. The simulation reveals that the anion part of IL plays a major role in Hg0 adsorption. Based on experimental results, a possible mechanism of Hg–IL interaction was elucidated; the imidazolium cation can form a complex with HgCl2 through the C2 hydrogen.

In this work, N-alkyl imidazolium based ionic liquids with phenolate anions have been used for the separation of naphthenic acid from model oil. The liquid-liquid equilibrium (LLE) data for the ternary mixture of [C n mim][Phe], dodecane and naphthenic acid were experimentally obtained at a constant temperature of 303.15 K and atmospheric pressure. The effect of chain length on the extraction capability was observed by calculating the distribution coefficient. The experimental tie line data was correlated using the non-random two liquid model (NRTL) and Universal Quasi Chemical (UNIQUAC) model and new interaction parameters for the ternary systems are reported. The experimental data provides a good correlation with the modelling data and a very low root mean square deviation (RMSD) value was observed for all the systems.

In this work, three novel imidazolium-based ionic liquids containing aromatic group in the cation combined with bis(trifluoromethylsulfonyl)imide anion were synthesized and characterized. Their thermophysical properties namely, density, viscosity, thermal decomposition, glass transition, and heat capacity were measured at various temperatures and atmospheric pressure. In addition, physicochemical properties such as molar volume (Vm) and crystal energy (UPOT) were also determined from the obtained density data. Novel group contribution parameters were obtained using Gardas and Coutinho model aiming at providing simple method to predict density and viscosity of ionic liquids.

In this work the de-acidification of dodecane was investigated using [DBU] based ionic liquid with thiocyanate [SCN] anion. The liquid-liquid equilibrium data for ternary mixture of {dodecane + naphthenic acid + [DBU-Hex][SCN]} were experimentally determined at a constant temperature and pressure. The ternary diagram shows that all the tie lines have a positive slope at all concentration of naphthenic acid, thus indicating that the ionic liquid is enough for the de-acidification of dodecane. The liquid-liquid equilibrium data was correlated using non-random two liquid (NRTL) model. An extremely good fit was obtained for all the tie lines using the NRTL model.

The effect of ethanedioic acid (EdA) functionalization on Al2O3 supported Ni catalyst was studied on the hydrodeoxygenation (HDO), isomerization, kinetics and Arrhenius parameters of octadec-9-enoic acid (OA) into biofuel in this report. This was achieved via synthesis of two catalysts; the first, nickel alumina catalyst (Ni/Al2O3) was via the incorporation of inorganic Ni precursor into Al2O3; the second was via the incorporation nickel oxalate (NiOx) prepared by functionalization of Ni with EdA into Al2O3 to obtain organometallic NiOx/Al2O3 catalyst. Their characterization results showed that Ni species present in Ni/Al2O3 and NiOx/Al2O3 were 8.2% and 9.3%, respectively according to the energy dispersive X-ray result. NiOx/Al2O3 has comparably higher Ni content due to the EdA functionalization which also increases its acidity and guarantees high Ni dispersion with weaker metal-support-interaction leading to highly reducible Ni as seen in the X-ray diffraction, X-ray photoelectron spectroscopy, TPR and Raman spectroscopy results. Their activities tested on the HDO of OA showed that NiOx/Al2O3 did not only display the best catalytic and reusability abilities, but it also possesses isomerization ability due to its increased acidity. The NiOx/Al2O3 also has the highest rate constants evaluated using pseudo-first-order kinetics, but the least activation energy of 176 kJ/mol in the biofuel formation step compared to 244 kJ/mol evaluated when using Ni/Al2O3. The result is promising for future feasibility studies toward commercialization of catalytic HDO of OA into useful biofuel using organometallic catalysts.

The solubility of cellulose in common solvents are very low. In order to overcome this problem, synthesis of nitrile-functionalized azepanium ionic liquids such as 1-butyl-1-(2-cyano-ethyl)-azepanium bromide, 1-butyl-1-(2-cyano-ethyl)-azepanium trifluoromethane sulfonate and 1-butyl-1-(2-cyano-ethyl)-azepanium trifluoro acetate were performed to test their cellulose solubilizing potential. 1 H NMR, 13 C NMR and CHN elemental analysis were used to characterize the synthesized ionic liquids. Thermo gravimetric analysis (TGA) and Differential Scanning Calorimetry(DSC) were used to determine the thermal properties of the ionic liquids. The ionic liquids were used for the dissolution of cellulose. Azepanium based nitrile-functionalized ionic liquids were able to dissolve up to 2 wt % of cellulose at 120 C in 48 hours. Thermal decomposition temperature and surface morphology of the cellulose was measured before and after the dissolution studies.The FTIR results showed that azepanium based ionic liquids are dissolving cellulose without any functionalization.

Magnesium(II) complexes, [Mg2+(hfac−)3][Cation+], were prepared as solids from hydrophobic hexafluoroacetylacetonate ionic liquids ([Cation+][hfac−] ILs) and Mg(Tf2N)2. 1-Butyl-3-methylimidazolium ([C4mim]), N-butylpyridinium ([C4Pyr]), N-butyl-N-methylpiperidinium ([C4Pip]), N-hexyl-N-methylmorpholinium ([C6Morp]) and N-butyl-N-methylpyrrolidinium ([C4pyrr]) were used as cationic cores. The [C4Pip][hfac], [C4Pyr][hfac] and [C6Morp][hfac] ILs were prepared for the first time. New Mg(II) complexes, [C4mim][Mg(hfac)3], [C4Pip][Mg(hfac)3], [C4Pyr][Mg(hfac)3], [C6Morp][Mg(hfac)3] and [C4Pyrr][Mg(hfac)3], were obtained from the [hfac] based ILs. The crystal structures of the novel Mg(II) complexes show the coordination of three [hfac] anions to the Mg2+ ion through the two oxygen atoms of each [hfac] anion.

In this study, functionalized silica supported ionic liquids phases (SILPs) were synthesized and characterized using Fourier Transform infrared (FTIR) spectroscopy, CHNS elemental analysis, thermo gravimetric analysis (TGA) and scanning electron microscopy (SEM). The adsorption of model naphthenic acid such as hexanoic acid, benzoic acid and commercial naphthenic acid from dodecane/kerosene was also investigated. The silica supported ionic liquids are good adsorbent for the removal of naphthenic acid from highly acidic model oil. The regeneration of supported ionic liquid phases as well as recovery of naphthenic acids from the supported ionic liquid phases (SILPs) was investigated.

Synthesis of new ionic liquids (ILs) based on diazobicyclo undacane (DBU) cation containing various alkyl groups such as ethyl, butyl, hexyl, octyl, decyl and tetradecyl group with dicyanamide anion were performed. The characterization of the ILs was carried out using NMR (1H and 13C) spectroscopy and elemental analysis. The water content, halide content and the thermal decomposition temperature of the synthesized ILs were determined. The density and viscosity of the ILs were measured in a large temperature range. The effect of temperature and alkyl spacer length on the physical properties such as density, viscosity and surface tension of the DBU based ILs were presented. The thermodynamic properties such as surface enthalpy and entropy, critical temperature and the total surface energy of the ILs were derived from their experimental surface tension and density data.

Thermophysical properties of imidazolium-based phenolate ionic liquids (ILs) were investigated over a wide temperature range. Different alkyl groups such as ethyl, butyl, hexyl, octyl, and decyl were tethered to the 1-methylimidazolium cation to study the effect of alkyl chain length on thermophysical properties such as density, viscosity, refractive index, heat capacity, and surface tension. The thermal stability of the phenolate ILs was investigated using thermogravimetric analysis. From the experimental values of density and surface tension, the molecular volume, standard molar entropy, lattice energy, surface entropy, and surface enthalpy of the ILs were calculated at 303.15 K.

Isolation of naphthenic acid from model oil using hydroxide based ionic liquid was investigated. A detailed de-acidification study at different temperatures and different ionic liquid/model oil was performed and the content of naphthenic acid before and after extraction was calculated. The ILs containing hydroxide anions has the potential to completely deacidify model oil having high TAN with extremely low ionic liquid /oil ratio.

Synthesis of a novel class of cyclic sulphonium based ionic liquids was performed. The ionic liquids were characterized using 1H NMR spectroscopy, FTIR spectroscopy and CHNS elemental analysis. The physicochemical properties of the ionic liquids such as density viscosity and thermal decomposition temperature of the synthesized ionic liquids were determined. The potential of these ionic liquids for the extractive desulphurization of model oil was investigated.

In this work, synthesis of 12 ionic liquids based on 1,8-diazobicyclo[5.4.0]undec-7-ene (DBU) cation with anions such as chloride, bromide, and thiocyanate were performed. The new ionic liquids were characterized using nuclear magnetic resonance spectroscopy and elemental analysis. The effect of alkyl spacer length on the physicochemical properties of DBU based ionic liquids was studied by attaching ethyl, butyl, hexyl, octyl, decyl, and tetradecyl groups to the DBU cation. The effects of temperature on the density and viscosity over a temperature range from 293.15 K to 373.15 K were recorded at atmospheric pressure. From the experimental density values, the thermal expansion coefficient values were calculated. The surface tension of the neat ionic liquids was measured at seven different temperatures (293.15 K, 303.15 K, 313.15 K, 323.15 K, 333.15 K, 343.15 K, and 353.15 K). The surface entropy and surface enthalpy were calculated from the experimental surface tension value at 303.15 K. The thermal behavi...

Ionic liquids with the bis(2-ethylhexyl)dimethylammonium cation, [BEDMA]+, were prepared by a halide-free route starting from the readily available secondary amine bis(2-ethylhexyl)amine. The following anions were considered: chloride, bromide, iodide, nitrate, hydrogensulphate, dihydrogenphosphate, formate, acetate, propionate, trifluoroacetate, methyl sulphate, methanesulphonate, tosylate, isonicotinate, nicotinate and picolinate. Several of the compounds are room-temperature ionic liquids, albeit with a high viscosity. All ionic liquids are soluble in water. The ionic liquids are very stable in strongly alkaline medium. No signs of decomposition could be observed by contact of the chloride ionic liquid with 50 wt% sodium hydroxide, even after prolonged heating at 80 C. The high stability against strong bases is attributed to the branched structure of the quaternary ammonium cation, which blocks the Hofmann elimination reaction. ispartof: RSC Advances vol:4 issue:9 pages:4472-4477 status: published

New dual functionalized N-oxyethylene-N-sulfopropyl imidazolium based ionic liquids (ILs) with unconventional anions for cellulose dissolution were synthesized and characterized (NMR, IR, HRMS, TGA, Td). The ILs were applied in studies on cellulose (MCC) dissolution. Results showed that varying the IL cation had greater impact on cellulose dissolution ability than the minor effect seen by anion exchange. Up to 20 wt-% MCC was dissolved in DMF/ILs solutions at 100 °C. The dual functionalized ionic liquids (ILs) were synthesized via the corresponding N-oxyethylene imidazolium sulfonate zwitterions (ZIs), which were prepared (74–99%) through a double N-imidazole alkylation procedure, including 1,3-propanesultone ring opening. The original MCC and the regenerated cellulose samples were characterized by XRD analysis.

The liquid-liquid extraction of Methylene Blue (MB) from aqueous solution was undertaken with 5 hydrophobic ionic liquids (ILs) based on bis(trifluoromethylsulfonyl)imide anion [NTf2] for comparison purpose where three of them were of commercial origin, 1-butyl-3-methyl imidazolium [BMIm], 1-hexyl-3-methylimidazolium [HMIm] and 1-octyl-3-methylimidazolium [OMIm] cations and the two other were purposely designed for this work, 1-hexyl-2-phenylimidazolium [HPhIm], and 1-benzyl-3-methyl-imidazolium [BnMIm]. Several parameters such as the place and nature of the aromatic ring, the length of the side alkyl chain and the ability to form hydrogen bonding were investigated to evaluate their impact on extraction performances. Results show that the incorporation of the functional group (aromatic group) not only led to excellent results of dye removal compared to commercially available ones but allowed easier recovery and subsequent reuse of the functionalized ILs. Conductor like Screening Model for Real Solvents (COSMO-RS) calculations were also performed to see the structural variations of the ILs their extraction capabilities of MB from water. The finding of this study may assist in reducing the pollution of wastewater from dye industries.

Ionic liquids are no longer a curiosity since they have shown tremendous potential in several key sectors of chemical sciences proven by the exponential number of publications in recent years. However, due to its toxicity and time-consuming synthesis route, these have become a technical hurdle of their use in pilot or industrial scales. Notably their syntheses not only time and energy consuming but also rather of dirty nature with the use of molecular solvents for synthesis and purification steps, leading to high production cost and impeding the possible further industrial outcome. In this preliminary work, we have developed a neat and quick synthesis pathway of di-cationic ionic liquids, reducing not only the necessary time from days to minutes but also the overall energy consumption resulted in high purity, increasing their potential as green alternative to common molecular organic solvents.

In these manuscript novel ionic liquids containing a new class of "phenolate" anions was synthesized and characterized. 1-methylmidazole with different alkyl chains such as butyl, hexyl and octyl groups was used as the cationic part. All the ionic liquids were obtained as liquids at room temperature. The synthesized ionic liquids were characterized using 1H NMR and 13C NMR spectroscopy. The thermal stability of the ionic liquids was studied using thermo gravimetric analysis (TGA). The effect of temperature on the density and viscosity of the ionic liquids were studied over a temperature range from 293.15 K to 373.15K at atmospheric pressure. From the experimental values of density, the molecular volume, standard molar entropy and the lattice energy of the ionic liquids were calculated.

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Two series of 1-alkylpyridinium and N-alkyl-N-methylpiperidinium ionic liquids functionalized with a nitrile group at the end of the alkyl chain have been synthesized. Structural modifications include a change of the alkyl spacer length between the nitrile group and the heterocycle of the cationic core, as well as adding methyl or ethyl substituents on different positions of the pyridinium ring. The anions are the bromide and the bis(trifluoromethylsulfonyl)imide ion. All the bis(trifluoromethylsulfonyl)imide salts as well as the bromide salts with a long alkyl spacer were obtained as viscous liquids at room temperature, but some turned out to be supercooled liquids. In addition, pyrrolidinium and piperidinium ionic liquids with two nitrile functions attached to the heterocyclic core have been prepared. The crystal structures of seven pyridinium bis(trifluoromethylsulfonyl)imide salts are reported. Quantum chemical calculations have been performed on model cations and ion pairs with the bis(trifluoromethylsulfonyl)imide anion. A continuum model has been used to take solvation effects into account. These calculations show that the natural partial charge on the nitrogen atom of the nitrile group becomes more negative when the length of the alkyl spacer between the nitrile functional group and the heterocyclic core of the cation is increased. Methyl or methoxy substituents on the pyridinium ring slightly increase the negative charge on the nitrile nitrogen atom due to their electron-donating abilities. The position of the substituent (ortho, meta, or para) has only a very minor effect on the charge of the nitrogen atom. The (15)N NMR spectra of the bis(trifluoromethylsulfonyl)imide ionic liquids were recorded with the nitrogen-15 nucleus at its natural abundance. The chemical shift of the (15)N nucleus of the nitrile nitrogen atom could be correlated with the calculated negative partial charge on the nitrogen atom.

Simple enolizable ketones such as acetophenones and benzalacetones were treated with malononitrile under Vilsmeier–Haack reaction conditions to afford 2-chloronicotinonitriles. The reaction proceeds via a one-pot chloromethyleneiminium salt mediated three-component reaction followed by sequential cyclization and aromatization under Vilsmeier–Haack reaction conditions.