Ammonium-based Room-temperature Ionic Liquids Research Articles

Assessing the impact of increase in the number of hydroxyl groups on the microscopic behaviors of ammonium-based room temperature ionic liquids: A combined fluorescence up-conversion, fluorescence correlation and NMR spectroscopic study

The current study aims to understand the impact of variation of number of hydroxyl groups on the cationic head of ammonium-based room temperature ionic liquids (RTILs) towards inter/intra molecular hydrogen bonding interaction, local structural organization and dynamics of the solvent systems. For this purpose, three hydroxyl functionalized ammonium based RTILs (HFILs) bearing different numbers of hydroxyl groups on the cationic head as well as a non-hydroxyl ammonium based RTIL have been examined using both ensembled average and single-molecule spectroscopy techniques. Investigation of solvent relaxation dynamics of all the concerned RTILs by the combination of femto-second fluorescence up-conversion techniques and time corelated single photon counting techniques reveals a bimodal solvent relaxation behaviour having a very fast sub-picosecond and a relatively slower picosecond to nanosecond solvation time component for all the RTILs. Interestingly, analysis of the rotational and translational diffusion dynamics of a few particular solutes shows that the solvent–solvent interaction in the poly-hydroxyl-based HFILs is substantially stronger than the solute–solvent interaction. Additionally, analysis of the rotational diffusion data reveals that all RTILs exhibit significant dynamic heterogeneity, which increases with increase the number of hydroxyl groups on the cationic head of HFILs. Moreover, PFG-NMR study have shown that the HFILs had considerably greater hydrodynamic radii than the non-hydroxyl RTILs, which is likely due to the result of stronger hydrogen bonding interaction between the hydroxyl groups and the constituent of the HFILs. The outcomes of all these investigations have essentially demonstrated that subsequent addition of hydroxyl functionalities to the cationic head of the RTILs significantly alter the intra/inter molecular interaction, local structural organisation and heterogeneity of the medium.

Correction to “New Series of Green Cyclic Ammonium-Based Room Temperature Ionic Liquids with Alkylphosphite-Containing Anion: Synthesis and Physicochemical Characterization”

Correction to “New Series of Green Cyclic Ammonium-Based Room Temperature Ionic Liquids with Alkylphosphite-Containing Anion: Synthesis and Physicochemical Characterization”

Synthesis of Quaternary Ammonium Room-Temperature Ionic Liquids and their Application in the Dissolution of Cellulose

In this work, several kinds of quaternary ammonium-based room-temperature ionic liquids (QA RTILs) are synthesized by alkylation and ion-exchange reactions for the rapid dissolution of cellulose. The applications of cellulose materials have been limited due to their poor solubility in conventional organic solvents, because of a high degree of structural regularity and a large number of hydrogen bonds. The prepared ionic liquids were identified by nuclear magnetic resonance, elemental analysis, and liquid chromatography-mass spectrometry. The results indicated that N,N,N-triethylhexan-1-aminium acetate (N6222OAc), tetrahexylammonium acetate (N6666OAc), and N,N,N,N′,N′,N′-hexaethyldecane-1,10-diaminium acetate (C10(N222OAc)2) exhibited good cellulose-dissolution without any pretreatment. The regenerated cellulose films with a low degree of crystallization of the cellulose II phase were also prepared easily in this process using N6222OAc due to its polar and small cation. These QA RTILs can be used as non-derivatizing solvents for cellulose and can also be easily recycled because of their thermostable and nonvolatile properties.

Synthesis, characterization and cellulose dissolution capabilities of ammonium-based room temperature ionic liquids (RTILs)

Abstract Green synthesis of room temperature ionic liquids (RTILs), are presented as friendly and challenging solvents for the effective dissolution of oil palm-lignocellulosic biomass. A series of Bronsted acidic-ionic liquids were prepared by the direct neutralization of diethyl dimethyl ammonium hydroxide with several (economical and environmental friendly) Bronsted acids as RTILs. The structural and physicochemical characterization was performed by applying various techniques as Fourier transform infrared (FT-IR), nuclear magnetic resonance (NMR), thermo gravimetric analysis (TGA), differential scanning calorimetry (DSC), zeta-nanosizer and dynamic light scattering (DLS) respectively, to state the effect of anion on the extended cellulose dissolution capabilities of the synthesized RTILs under mild conditions. As a polysaccharide solvent, diethyl dimethyl ammonium phosphate (A1P) showed the extreme capability to extract 65 % of cellulose from biomass without any pretreatment for 30 min. The present study could be a significant step toward the synthesis of efficient RTILs and generating upgraded cellulose for Hi-tech engineered composites and energy concerns.

Quaternary Ammonium-Based Room Temperature Ionic Liquids as Components of Carbonate Electrolytes for Li-ion Batteries: Electrochemical Performance and Thermal Properties

Quaternary Ammonium-Based Room Temperature Ionic Liquids as Components of Carbonate Electrolytes for Li-ion Batteries: Electrochemical Performance and Thermal Properties

Quaternary Ammonium-Based Room Temperature Ionic Liquids as Components of Carbonate Electrolytes for Li-ion Batteries: Electrochemical Performance and Thermal Properties

Quaternary Ammonium-Based Room Temperature Ionic Liquids as Components of Carbonate Electrolytes for Li-ion Batteries: Electrochemical Performance and Thermal Properties

New Series of Green Cyclic Ammonium-Based Room Temperature Ionic Liquids with Alkylphosphite-Containing Anion: Synthesis and Physicochemical Characterization.

A new series of 12 cyclic ammonium-based room temperature ionic liquids (RTILs) containing an alkylphosphite anion have been synthesized by an alkylation reaction between cyclic tertiary amines and dialkylphosphite. This method constitutes an eco-friendly pathway to RTILs that does not generate any secondary byproducts and avoiding the metathesis reaction involving uses of nonfriendly or expensive salts. Their physicochemical and electrochemical properties have been investigated. The temperature dependency of density, dynamic viscosity, and ionic conductivity were determined at temperatures varying from 293.15 to 323.15 K and were discussed on a structural basis. For the prepared RTILs, the viscosity values are fairly high and low ionic conductivity as compared to usual ILs. The transport properties were found to be temperature-dependent and followed the Arrhenius law. The RTILs potential windows (ΔE) are comprised between 3.00 and 4.77 V. The electrochemical stability seems to be influenced by the alkyl ...

Electrochemical oxidation of proteins using ionic liquids as solubilizers, adsorption solvents and electrolytes

This study focuses on application of room temperature ionic liquids (RTILs) as solubilizers, adsorption solvents and supporting electrolytes for electrochemical analysis of human and bovine serum albumins, HSA and BSA. The proteins were analyzed by ex situ, adsorptive transfer, square-wave voltammetry (SWV) at a basal-plane pyrolytic graphite electrode after solubilization using imidazolium- and ammonium-based RTILs. The application of RTILs enabled SWV scan from 0 to +1.5V (vs. Ag/AgCl/3M KCl) without interference with the anodic response of the proteins. Concretely, Tyr (Y) and Trp (W) oxidation currents of HSA and BSA, peak Y&W around +0.85V, were observed and characterized under different RTILs and RTIL/water conditions. The electrochemical data were supported by electrophoresis under denaturing and native conditions. These provided evidence for the structural changes and stability of the studied proteins in the presence of RTILs. The data acquired using BSA and HSA model proteins, could be used in further applications of RTILs in protein electrochemistry and for developing new protein sensing strategies.

Properties of New Asymmetrically Quaternized Dicationic Ammonium Based Room-Temperature Ionic Liquids with Ether Functionality

Eleven asymmetrically quaternized dicationic ammonium-based room-temperature ionic liquids (DRTILs) with bis(trifluoromethanesulfonyl)imide (TFSI) were synthesized and characterized, along with 11 analogous dibromide precursors. Two-step synthesis was used to diquaternize tetramethyl-1,3-propanediamine and 2-(dimethylamino)-ethyl ether amines with a variety of alkyl and ether functionalized side chain groups (R1 ≠ R2). Each salt contain 1 to 3 ether groups located either in a linkage or in a side chain moieties. Structural and thermoanalytical properties, water content, and viscosity have been characterized using, for example, NMR, mass spectrometry (MS), X-ray diffraction, and thermal analysis (TG/DTA, DSC). DRTILs have extensive fluid ranges [(∼330 to 370) °C], which are the consequence of low glass transition [(−60 to −40) °C] and high thermal degradation temperatures of the salts [(279 to 325) °C; heating rate 1.25 °C·min–1]. Thermal stabilities of DRTILs were examined as a function of a heating rate [(1.25, 2.5, 5, 10, and 20) °C·min–1], and degradation onset temperature overshoots of about (45 to 55) °C were observed between the slowest and the fastest heating rates. Thereby it is suggested that ILs should preferably be analyzed by TG using heating rates of ≤ 5 °C·min–1 in order to reduce the possibility of an erroneous interpretation of the thermal stability. The ether group count and its location affected the viscosities significantly, which varied between (1150 and 6670) mPa·s at RT and lowered significantly when heated at 60 °C, being typically ≤ 200 mPa·s. The ether-functionalized DILs are potentially applicable in various IL applications, such as lubricants, heat transfer fluids, high temperature synthesis solvents, or as stationary phase in applications such as gas chromatography, MS, and capillary electrophoresis.

Synthesis of Carbonyl Compounds from Alcohols Using Electrochemically Generated Superoxide Ions in RTILs

We show that the superoxide ion (O2 •−) generated electrochemically from oxygen dissolved in room-temperature ionic liquids (RTILs) reacts with primary and secondary alcohols to form the corresponding ketones and carboxylic acids, respectively. Specifically, we study the conversion of benzhydrol to benzophenone and benzyl alcohol to benzaldehyde/benzoic acid. The kinetics (e.g., rate, selectivity, and yield) for these reactions are also determined as functions of the variations in the structure of the ionic liquids. The RTILs used here are imidazolium-based cations where the functional groups on the imidazolium ring are modified. Specifically, 1-butyl-3-methylimidazolium hexafluorophosphate [bmim][PF6], 1-butyl-2,3-dimethylimidazolium hexafluorophosphate [bdmim][PF6], and 1-hexyl-3-methylimidazolium hexafluorophosphate [hmim][PF6] are used as the reaction medium. These results are compared to an ammonium-based RTIL (N-butyl-N-trimethylammonium bis(trifluoromethylsulfonyl)imide). The results show that the nucleophilic attack by the O2 •− of both the RTIL and the alcohol, especially that of the H atom at the R2 position of the [bmim][PF6] and [hmim][PF6], greatly affects the yields. No RTIL degradation products were detected for the reactions in [bdmim][PF6] and N-butyl-N-trimethylammonium bis(trifluoromethylsulfonyl)imide ionic liquids. For the benzyl alcohol oxidation reaction in the RTIL, N-butyl-N-trimethylammonium bis(trifluoromethylsulfonyl)imide, benzaldehyde formed did not undergo further oxidation to form benzoic acid, which may be due to the greater hydrophobicity of this RTIL. The competitive reaction kinetics between the alcohol and RTIL component must be considered in the selection of the RTIL solvent system.

The controlled synthesis of stable gold nanoparticles in quaternary ammonium ionic liquidsby simple heating

Stable gold nanoparticle (AuNP) colloids were synthesized in a class ofquaternary ammonium-based room-temperature ionic liquids (QAILs),[Me3NC2H4OH] + [ZnnCl2n + 1] − (n = 1 or 2), by heatingin air at 135–145 °C. The QAIL was employed as a solvent, a reducing agent, and as a stabilizer.The size of the QAIL–AuNPs can be varied between 20 and 40 nm bychanging the reaction temperature. A symproportionation reaction wasemployed to further decrease the size of the AuNPs by the addition ofAu3 + ions. The surface covering of QAIL on the AuNPs had a significant impact on their surfaceplasmon resonance (SPR), which was red-shifted. The AuNPs synthesized by this simpleand environmentally friendly reaction can be realized in several minutes and also exhibithigh stability and good reproducibility, providing a new facile approach to metalnanoparticle preparation.

Gas permeabilities, solubilities, diffusivities, and diffusivity correlations for ammonium-based room temperature ionic liquids with comparison to imidazolium and phosphonium RTIL data

Abstract Like our previous work with imidazolium- and phosphonium-based ionic liquids, we report diffusivities over a range of viscosities (71–532 cP) and develop a predictive diffusivity correlation. Reported are the permeability, solubility, and diffusivity data for nine gases in nine ammonium RTILs liquids at 30 °C, as determined with a lag-time technique. The gas solubilities and diffusivities of the ammonium RTILs are of the same magnitude as those for the phosphonium and imidazolium RTILs. The ammonium RTILs used, in this study, included cations with both N-alkyl groups and branched alkyl groups. We also report on ammonium-based RTILs derived from quaternary ammonium surfactants. These surfactants-derived ammonium-based RTILs offer a relatively inexpensive alternative to imidazolium-based RTILs. We compare and contrast the thermodynamic (solubility) and transport (diffusivities) phenomena in the ammonium-based RTILs with both the imidazolium and the phosphonium RTILs in the context of being working fluids in a chemical process. From this comparison came certain “universal” trends for diffusivity in RTILs. Specifically, diffusivity scales roughly with the inverse of the square-root of viscosity and inversely with solute molar volume to the power of 1–1.3. This means that diffusivity, in RTILs, is less dependent on viscosity, and more dependent on solute size than predicted by the conventional Stokes–Einstein model. The gases tested were carbon dioxide, nitrogen, oxygen, methane, ethylene, propylene, 1-butene, butane, and 1,3-butadiene.

Density and Surface Tension Measurements of Imidazolium-, Quaternary Phosphonium-, and Ammonium-Based Room-Temperature Ionic Liquids: Data and Correlations

ADVERTISEMENT RETURN TO ISSUEPREVAddition/CorrectionDensity and Surface Tension Measurements of Imidazolium-, Quaternary Phosphonium-, and Ammonium-Based Room-Temperature Ionic Liquids: Data and CorrelationsPrem Kilaru, Gary A. Baker, and Paul ScovazzoCite this: J. Chem. Eng. Data 2008, 53, 2, 613Publication Date (Web):January 26, 2008Publication History Published online26 January 2008Published inissue 1 February 2008https://doi.org/10.1021/je800030sCopyright © 2008 American Chemical SocietyRIGHTS & PERMISSIONSArticle Views655Altmetric-Citations3LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (24 KB) Get e-AlertsSUBJECTS:Anions,Cations,Color,Halogens,Inorganic compounds Get e-Alerts

Correlations of Low-Pressure Carbon Dioxide and Hydrocarbon Solubilities in Imidazolium-, Phosphonium-, and Ammonium-Based Room-Temperature Ionic Liquids. Part 1. Using Surface Tension

This paper examines the dependence of gas solubility on the surface tension of room-temperature ionic liquids (RTILs). The solubility phenomena of the CO2, ethylene, propylene, 1-butene, and 1,3-butadiene in five imidazolium-, four phosphonium-, and eight ammonium-based RTILs are explained using the Hansen RTIL solubility parameters that were calculated from surface tension measurements. The Hansen solubility parameters were estimated from the surface tensions of the respective RTILs with a proportionality constant that is a function of the ratio of the number of nearest-neighbor interactions in the bulk liquid to those on the surface. The calculated solubility parameters are almost independent of temperature. The surface tension solubility parameter model explains the effect of variation of alkyl chain lengths in the cations and the variation of the RTIL anions on gas solubility within an error of ±15%. The analysis may indicate that the CO2−anion interaction is not the dominant factor that determines th...