Synthesis Of Ionic Liquids Research Articles

Synthesis and characterisation of novel nopyl-derived phosphonium ionic liquids

A series of novel nopyl-derived chiral phosphonium ionic liquids have been successfully synthesised and characterised. Analysis of each novel ionic liquid was conducted in order to confirm structure, purity and thermal stability.

New Thiourea-Based Ionic Liquid as an Electrolyte Additive to Improve Cell Safety and Enhance Electrochemical Performance in Lithium-Ion Batteries.

Our society is critically dependent on lithium-ion batteries (LIBs) as a power source for portable electronic gadgets. One of the major problems with these batteries is the degradation of the materials inside them. In addition to the reduced cell life, building-up of these degraded products inside the cells is very detrimental to the safe operation. Herein, we report the synthesis and characterization of a novel thiourea-based room temperature ionic liquid (IL), 3-heptyl-1-(3-(3-heptyl-3-phenylthioureido)propyl)-1H-imidazole-3-ium hexafluorophosphate. Its electrochemical and thermal properties including transport phenomena have been studied. It is proposed to be used as a nominal additive to commercially used electrolytes, ethylene carbonate and di-methyl carbonate mixtures. The comparative performance characteristics of the LIBs in the presence and the absence of this IL additive have been demonstrated with a traditional lithium nickel cobalt manganese oxide cathode (NMC111), a graphite anode, and an ethylene carbonate and di-methyl carbonate (1:1, v/v) electrolyte. It is further demonstrated that use of this electrolyte additive in batteries helps to address some of the major concerns of the conventional electrolytes such as safety issues and cycling performance as well as coulombic efficiency with enhanced discharge capacities.

Electrochemical performance of Li-rich NMC cathode material using ionic liquid based blend polymer electrolyte for rechargeable Li-ion batteries

In this paper, synthesis of lithium rich nickel manganese cobalt oxide cathode material (Li1·2Ni0·6Mn0·1Co0·1O2) and ionic liquid (IL) based blend gel polymer electrolytes (BGPEs) are reported. Li1.2Ni0.6Mn0.1Co0.1O2 cathode material as well as BGPEs are prepared by solution combustion and solution casting technique, respectively. X-ray diffraction (XRD) technique clearly reveals that the cathode material is in pure phase, having well defined layered structure. Thermal, electrical and electrochemical properties of BGPEs are investigated by using thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), impedance spectroscopy and linear sweep voltammetry (LSV). It is observed that 70 wt% IL containing BGPE provides maximum Li-ion conductivity (σLi+∼1.1 mS cm−1), thermal (∼250 °C) and electrochemical stability (∼4.3 V vs. Li/Li+). Electrochemical analysis of the cell (Li/70 wt% BGPE/Li1·2Ni0·6Mn0·1Co0·1O2) provides well defined redox peaks corresponding to Ni2+/Ni4+ and it delivers specific discharge capacity of 166 mAh g−1 at 0.1 C-rate and 97% efficiency upto 140 cycle.

Synthesis, NMR, Raman, thermal and nonlinear optical properties of dicationic ionic liquids from experimental and theoretical studies

Two new di-cationic imidazolium based ionic liquids (ILs) containing chloride, (bisImCl), or hexafluorophosphate anions (bisImPF6) have been synthesized and characterized by FT-Raman and 1H- and 13C NMR spectroscopies. The p-xylyl group acts a spacer between two imidazolium rings in the cation. The influence of the anions on thermal properties of the compounds has been investigated. Both bisImCl and bisImPF6 have shown good thermal stability up to at least 280 °C. Intermolecular and cation-anion interactions have been investigated by NMR spectroscopy. B3LYP/6-311++G∗∗ calculations have optimized the structure of bisIm cation with both anions. Both Cl are found to be in a monodentate coordination, while in bisImPF6 only one PF6 group presents monodentate coordination. AIM calculations at the same level of theory have evidenced a higher number of interactions in bisImPF6, as compared to bisImCl. A complete assignment of the vibrational frequencies for the cation, bisImCl and bisImPF6 are here reported together with a set of harmonic scaled force constants calculated for the cation and bisImCl. Further, polarizability (α) and the static first hyperpolarizabilities (β) of these ILs are calculated by different DFT functionals in order to understand nonlinear optical (NLO) properties. It is observed an inverse correlation between the predicted β value and the HOMO-LUMO energy difference (Δε) from two state models. The high gap value observed for bisImPF6 justifies its low reactivity, as supported by the high number of interactions predicted for this ionic liquid.

Selective cloud point extraction of thorium (IV) using tetraazonium based ionic liquid

This study involves the synthesis and characterization of a new tetra-cationic surface-active ionic liquid (SAIL) based on tetraazonia-tricyclo[3.3.1.13,7]decane derivative. The surface properties of the synthesized SAIL revealed good surface activity, self-aggregation and clouding ability indicating its feasibility in surfactant-mediated extraction applications. Applying the synthesized SAIL combined with Triton X-100 as a mixed surfactant system in cloud point extraction of Th(IV) ions resulted in a sensitive and selective extraction procedure. Arsenazo III was used as Th(IV) chelating agent and the pre-concentrated chelate was spectrophotometrically determined. The main variables affecting the extraction efficiency were systematically investigated. The highest extraction efficiency was achieved at pH 5.0 with 2.5 × 10−3 mol L-1 SAIL and 1.0 % (v/v) Triton X-100. At the optimized conditions, the developed method exhibited a linear working range from 10.0 to 100.0 ng mL-1 with a detection limit of 77.0×10-2 ng mL−1. The interfering impact of various ions on Th(IV) extraction efficiency was evaluated. The applicability and reliability of the developed method were evaluated by determining Th(IV) at trace levels in various water samples and the obtained recovery values were ranging from 98.0 to 101.4%. The developed CPE method is sensitive, simple, reliable and consistent with the green chemistry principles.

Synthesis and Physical Properties of Protic Triaminocyclopropenium Ionic Liquids

AbstractA range of protic triaminocyclopropenium salts with cations of the general formula [C3(NR2)2(NR'H)]+ (R=Me, Et; R’=H, Et, Pr, Bu, Pe, Hex, allyl, CH2CH2OMe) have been prepared by treatment of diaminoalkoxycyclopropenium salts with primary amines. Most salts were prepared with the bistriflamide anion, but the cation [C3(NEt2)2(NBuH)]+ was also combined with methylsulfate, dicyanamide, and tetrafluoroborate. The triprotic ionic liquid (IL) [C3(NPhH)3]NTf2 was also prepared and characterized. These protic ILs are characterised by thermal (DSC and TGA), density, viscosity and conductivity. The miscibility/solubility studies of these protic ILs has been determined in range of polar and non‐polar organic solvents. Comparisons have been made with similar series of aprotic bistriflamide (NTf2–) and dicyanamide (DCA) salts that have been reported previously.

PURIFICAÇÃO DO BIODIESEL DE ÓLEO DE SOJA POR MEIO DO EMPREGO DE LÍQUIDOS IÔNICOS ANÁLOGOS BASEADOS EM CLORETO DE COLINA

Os processos tradicionais de purificação do biodiesel são onerosos e lentos, gerando grandes volumes de efluentes para atender os parâmetros de qualidade exigidos pela legislação. Este trabalho avalia os efeitos de novas combinações para a síntese de líquidos iônicos (LI’s) sobre a eficiência do solvente na remoção de impurezas do biodiesel de soja. Os LI’s análogos a base de cloreto de colina, sintetizados com a mistura eutética de glicerol, etilenoglicol e trietilenoglicol, foram usados para lavar o biodiesel pré-purificado em diferentes razões. O LI L9 composto por cloreto de colina, glicerol e trietilenoglicol (1:2:1), teve a maior eficiência (98,05%) quando usado na razão R2 (1:1), com um tempo ótimo de lavagem de 60 minutos. O biodiesel bruto também foi purificado com o novo solvente e apresentou uma boa eficiência mesmo quando reutilizado, em conformidade com a RANP 45/2014.

Chiral Ionic Liquids: Structural Diversity, Properties and Applications in Selected Separation Techniques.

Ionic liquids (ILs) are chemical compounds composed of ions with melting points below 100 °C exhibiting a design feature. ILs are commonly used as the so-called green solvents, reagents or highly efficient catalysts in varied chemical processes. The huge application potential of ionic liquids (IL) justifies the growing interest in these compounds. In the last decade, increasing attention has been devoted to the development of new methods in the synthesis of stable chiral ionic liquids (CILs) and their application in various separation techniques. The beginnings of the successful use of CILs to separate enantiomers date back to the 1990 s. Most chiral ILs are based on chiral cations or chiral anions. There is also a limited number of CILs possessing both a chiral cation and a chiral anion. Due to the high molecular diversity of both ions, of which at least one has a chiral center, we have the possibility to design a large variety of optically active structures, thus expanding the range of CIL applications. Research utilizing chiral ionic liquids only recently has become more popular. However, it is the area that still has great potential for future development. This review aimed to describe the diversity of structures, properties and examples of applications of chiral ionic liquids as new chiral solid materials and chiral components of the anisotropic environment, providing chiral recognition of enantiomeric analytes, which is useful in liquid chromatography, countercurrent chromatography and other various CIL-based extraction techniques including aqueous biphasic (ABS) extraction systems, solid–liquid two-phase systems, liquid–liquid extraction systems with hydrophilic CILs, liquid–liquid extraction systems with hydrophobic CILs, solid-phase extraction and induced-precipitation techniques developed in the recent years. The growing demand for pure enantiomers in the pharmaceutical and food industries sparks further development in the field of extraction and separation systems modified with CILs highlighting them as affordable and environmentally friendly both chiral selectors and solvents.

Low viscosity lactam-based ionic liquids with carboxylate anions: Synthesis, characterization, thermophysical properties and mutual miscibility of ionic liquid with alcohol, water, and hydrocarbons

Low viscosity lactam-based ionic liquids (ILs) were synthesized by a neutralization reaction between a cyclic amide (lactam), such as γ-butyrolactam, ε-caprolactam, 12-aminododecanolactam, and 1-octyl-2-pyrrolidone with a Brønsted acid (acetic, butyric, or hexanoic acids), in a total of eight systems. From this experimental matrix, the following five ILs have been formed: γ-butyrolactam + acetic acid (BTA), γ-butyrolactam + butyric acid (BTB), and γ-butyrolactam + hexanoic acid (BTH); and, ε-caprolactam + acetic acid (CPA) and ε-caprolactam + hexanoic acid (CPH), all systems presenting low viscosity. All synthesized ILs were characterized by FTIR and 1H NMR spectroscopies. Volumetric and transport properties (density and viscosity), along with thermal decomposition and ionic conductivity analyses have been experimentally determined. Mutual miscibility of these ILs against n-butanol, water, toluene, heptane, ethylbenzene, styrene, cyclohexane, and cyclohexene systems were determined at 293.15 K and atmospheric pressure (P = 101.325 kPa). Cation and anion structures influence on the mixtures were discussed. Ionic liquids containing lower chain anions formed two phases with heptane and were completely miscible in aromatic hydrocarbons, water and n-butanol. While ionic liquids with higher chain anions showed partial miscibility only in water. The miscibility of n-heptane increases when the hydrophobic character of ILs increases, as observed for ILs produced from γ-butyrolactam (BTA, BTB, and BTH). ILs-solvents miscibilities are a function of the lactam ring chain, decreasing in aliphatic hydrocarbons and increasing in cyclic hydrocarbons.

Synthesis, characterization and application of a non-flammable dicationic ionic liquid in lithium-ion battery as electrolyte additive

A novel dicationic room temperature ionic liquid, 1,1′-(5,14-dioxo-4,6,13,15-tetraazaoctadecane-1,18-diyl) bis(3-(sec-butyl)-1H-imidazol-3-ium) bis((trifluoromethyl)-sulfonyl) imide has been synthesized and fully characterized. Its thermal and electrochemical analyses along with transport properties have been studied. We propose it as a potential nominal additive to the commonly used conventional organic carbonate electrolyte mixture and study its adaptability in Lithium-ion batteries which are the prime power sources for ultraportable electronic devices. We have compared the performance characteristics of the full cells made without and with this ionic liquid. The cells comprise lithium nickel cobalt manganese oxide cathode, graphite anode and ethylene carbonate - dimethyl carbonate (1:1, v/v + LiPF6) mixture electrolyte with nominal amount of ionic liquid as additive. The major concern with conventional electrolytes such as degradation of the materials inside batteries has been addressed by this electrolyte additive. Additionally, this additive is safer at relatively higher temperature. In its presence, the overall battery life is enhanced and it shows good cycling performance and coulombic efficiency with better discharge capacities (22% higher) after 100 cycles. Even after the increase in current rate from 10 mA/g to 100 mA/g, the cell still retains around 73% of capacity.

Synthesis, Characterization and Applications of Dicationic Ionic Liquids in Organic Synthesis

Dicationic ionic liquids are an emerging group of Ionic Liquids (ILs) that are currently receiving much attention as green reaction media and catalysts. Because of a great number of possible combinations of cations and anions, the physical and chemical properties of dicationic ionic liquids are more tunable and broader than monocationic ILs. Therefore, their unique properties have made them the target of many applied and fundamental researches. Actually, dicationic ionic liquids are more effective and rather fascinating than traditional monocationic ILs. So, due to greater versatility and diversity, their applications in organic synthesis have been extensively grown. In this review, we have focused on the synthesis, characterization and applications of dicationic ionic liquids, especially, in organic synthesis.

Synthesis and evaluation of oil-soluble ionic liquids as multifunctional lubricant additives

Two novel ionic liquids, (4(or 5)-methyl-benzotriazole-1-ylmethyl) -octadec-9-enyl-ammonium bis(2-ethylhexyl) phosphate and (4(or 5)-methyl-benzotriazole-1-ylmethyl)- dioctyl-ammonium bis(2-ethylhexyl) phosphate, were synthesized and evaluated as multi-functional additives in poly-alpha-olefin (PAO). Due to the existence of a long hydrocarbon chain in both anion and cation partials, these two ILs exhibit excellent solubility in various base oils. Corrosion and rust tests revealing that the addition of merely 0.1% ILs into PAO10 can effectively strengthen the anti-corrosion and anti-rust performance of base oil. Tribological results showed that these newly developed ILs can not only enhance the anti-wear performance but also improve the load-carrying capacity of the PAO10. Worn surface analyses revealed that a boundry lubrication film composed with FePO4 and nitrogen is formed, which is responsible for the outstanding tribological performance of the ILs.

Biocompatible amino acid-based ionic liquids for extracting hormones and antibiotics from swine effluents

The generalized use of antibiotics and hormones in swine feed has triggered a growing concern on their presence in wastewater effluents and manure. Therefore, the implementation of strategies for their removal is a matter of practical significance and the synthesis of biocompatible ionic liquids to be used as segregation agents in aqueous waste effluents could be a suitable means for removing these emerging contaminants. In this work, the salting out capacity of cholinium alaninate, (N1112OHAla) in aqueous streams containing surfactants (Triton X-100) was demonstrated. Afterwards, its ability to separate a hormone (17-β estradiol) and antibiotics belonging to tetracycline and fluoroquinolone families was investigated in an aqueous synthetic swine effluent at environmental conditions. It was checked that the cautious selection of the feed compositions allowed high levels of hormone extraction (E) and partition coefficients (K): E > 90% and K > 13.86, in surfactant rich-phase. Antibiotics migrated to any of the two phases depending on system compositions. However, the decisive addition of a cationic surfactant (2% CTAB) led to increased extraction efficiencies of chlortetracycline (K = 15.77 and E = 92.5%), proving the versatility of the process.

Synthesis of a magnetic ionic liquid ([C12mim]FeCl4) and its interactions with low-rank coal

Synthesis of a magnetic ionic liquid ([C12mim]FeCl4) and its interactions with low-rank coal

Synthesis and Analysis of Ionic Liquid As Additive for Li-Ion Battery Electrolyte

Lithium ion batteries are promising power sources for various applications such as portable electronics and electrical vehicles, due to their high specific energy density and long cycle life. As one key component of lithium ion battery, the electrolyte should allow lithium ion transport but prevent electron conduction. One big challenge of lithium ion battery is that the high voltage and high current in the charge process can cause self-decomposition of the electrolyte, leading to combustion of the battery. In order to solve the combustion problem in the fast charge process, new electrolyte materials with high ionic conductivity and good chemical stability are urgently needed.Ionic liquid is usually organic salt consisting of anion and cation with low vapor pressure, high boiling point, high ionic conductivity, large specific heat capacity, and non-flammable characteristics. Ionic liquid is aqueous at or near the room temperature. The features of ionic liquid such as the high heat resistance and wide liquid temperature range make it a promising electrolyte material for lithium ion battery.This project aims at tailoring the suitable structure of ionic liquid as the additive for lithium ion battery. Our ionic liquid is a designed composition of anion of TFSI as SEI forming additive and imidazole based cation. A two-step process has been developed for synthesizing ionic liquid. The physical and chemical properties of the ionic liquid were measured to evaluate the feasibility of applying ionic liquid to lithium ion battery.Both the density and the viscosity of the ionic liquid are measured at different temperatures. The density was found to decrease linearly with temperature in both single and binary system. The determined negative excess molar volume of ethyl acetate and ionic liquid system is relative to the interaction between different molecules. The viscosity of the analyzed electrolyte solvent was found to decrease linearly with increasing temperature. Arrhenius-like law was found to be able to fit the measured data well. The fitting parameters were able to predict viscosity at different temperature.The conductivity of the whole electrolyte system and compatibility with the active materials will be tested and discussed in the next study.

Non-invasive Transdermal Delivery of Human Insulin Using Ionic Liquids: In vitro Studies.

In this research project, synthesis and characterization of ionic liquids and their subsequent utilization as facilitators of transdermal delivery of human insulin was pursued. Choline geranate and choline oleate ionic liquids (and their deep eutectic solvents) were produced and characterized by nuclear magnetic resonance (1H NMR), water content, oxidative stability, cytotoxicity and genotoxicity assays, and ability to promote transdermal protein permeation. The results gathered clearly suggest that all ionic liquids were able to promote/facilitate transdermal permeation of insulin, although to various extents. In particular, choline geranate 1:2 combined with its virtually nil cyto- and geno-toxicity was chosen to be incorporated in a biopolymeric formulation making it a suitable facilitator aiming at transdermal delivery of insulin.

Efficient pyridinium-based ionic liquid for deep oxidative desulfurization of model oil

The present research work reports the synthesis of a pyridinium-based ionic liquid (IL) 1-butyl-4-methylpyridinium benzoate [BMPy][(C6H5)COO]. Full characterization of [BMPy][(C6H5)COO] was then performed using 1H NMR, 13C NMR, FTIR, TGA, and elemental analysis. [BMPy][(C6H5)COO] was firstly applied in the extractive desulfurization (EDS) of a model oil consisting of dibenzothiophene (DBT) and dodecane (1000 ppm), where 63.1% DBT-removal efficiency was revealed under optimum conditions of 60 °C, 90 min, and a mass ratio of 1:1 (IL/model oil). To further improve the efficiency of DBT-removal, [BMPy][(C6H5)COO] was subsequently employed in oxidative desulfurization (ODS), where it acted as an extractant with H2O2 as an oxidant. Successfully, 98.9% of DBT was removed at 60 °C and within 90 min using an equal mass ratio of IL/model oil and molar ratio (8) of O/S. Moreover, [BMPy][(C6H5)COO] could be regenerated and recycled for five consecutive runs while retaining approximately the same ODS efficiency. A mechanism of ODS using [BMPy][(C6H5)COO] was proposed. The π–π interactions between IL's structure and DBT were suggested to be the driving force behind the extraction power of [BMPy][(C6H5)COO]. Furthermore, recommendations for future research directions of ODS using ILs were introduced. Finally, a comparison of ODS results for [BMPy][(C6H5)COO] and different pyridinium-based ILs for various model oils was conducted where [BMPy][(C6H5)COO] showed to be a competitive and promising type of pyridinium-based IL for use in the ODS processes.

Synthesis of task-specific imidazolium ionic liquid as an efficient catalyst in acetylation of alcohols, phenols, and amines

Herein, we report the synthesis of task-specific amino-functionalized imidazolium ionic liquid, acetate1-(2-tert-butoxycarbonylamino-ethyl)-3-methyl-3H-imidazol-1-ium; (Boc-NH-EMIM.OAc), as an efficient catalyst for the acetylation of alcohols, phenols, and amines in the presence of acetic anhydride (acetylating reagent). Remarkably, acetic anhydride in the presence of 10 mol% of catalyst (Boc-NH-EMIM.OAc) under solvent-free conditions showed excellent acetylation activity in shorter duration of time. On the basis of this, a general procedure for acetylation of alcohols, phenols, and amines has been developed. The ionic liquid (Boc-NH-EMIM.OAc) can be readily recovered and reused successfully up to four consecutive cycles without any significant loss of its catalytic activity. We have been able to show that this acetylating method has many advantages. It gives high yields, takes shorter time, and develops the possibility of benign environmental-friendly process.

The structure elucidation of new mono-core dicationic salt-containing chlorosulfonate counterion: Raman study of a pure sample of chlorosulfonate anion in the solid and liquid state

This paper presents the design and synthesis of new ionic liquid containing dication of 1H,4H-piperazine-diium ring and two chlorosulfonate as counterions. The structure elucidation of new ionic organo-compound was performed by 1D and 2D NMR, FTIR, Raman, and mass spectrum. Then, the correct structure was elucidated by COSY which was supported by Raman study. IR and Raman spectra of liquid and solid-state of 1H,4H-piperazine-diium dichlorosulfonate are studied. Assignments are made for FTIR and Raman peaks, and our results are compared with previous reports in the literature.

Self-Assembled Ionic Liquid for Highly Efficient Electron Transport Layer-Free Perovskite Solar Cells.

Electron transport layer (ETL)-free perovskite solar cells (PSCs) are attractive because they have fewer layers and hence are lower in cost, but their inferior photovoltaic performance, as compared to ETL-containing PSCs, greatly restricts their practical application. This study concerns the design and synthesis of a hydroxyethyl-functionalized imidazolium iodide ionic liquid, the determination of its single crystal structure, and its self-assembly on a conductive substrate for ETL-free PSCs. The self-assembly of the ionic liquid on the conductive substrate is found to lower the work function of the conductive substrate and enhance interfacial electron extraction while retarding interfacial charge recombination. As a consequence, the power conversion efficiency is improved remarkably from 9.01 % to 17.31 % upon self-assembly of the ionic liquid on the conductive substrate. This finding provides a new way to assemble highly efficient ETL-free PSCs.