Phosphine oxide functionalised imidazolium ionic liquids as tuneable ligands for lanthanide complexation

A series of novel, phosphine oxide functionalised ionic liquids have been synthesised and their application as tuneable lanthanide complexing agents is demonstrated.

High-pressure volumetric properties of imidazolium-based ionic liquids: Effect of the anion

The densities of five imidazolium-based ionic liquids (ILs) (1-butyl-3-methylimidazolium tetrafluoroborate, [CiC4-Im][BF 4]; 1-butyl-3-methylimidazolium hexafluorophosphate, [CiC 4Im][PF6]; 1-butyl-3-methylimidazolium bis{(trifluoromethyl)sulfonyl}imide, [C1C4Im][Tf 2N]; 1-ethyl-3-methylimidazoliumbis{(trifluoromethyl)sulfonyl}-imide, [C1C2Im][Tf2N]; l-ethyl-3-methylimidazolium ethylsulfate, [C1C2Im][EtSO4]) were measured as a function of temperature from (293 to 415) K and over an extended pressure range from (0.1 to 40) MPa using a vibratingtube densimeter. Knowledge of the variation of the density with temperature and pressure allows access to the mechanical coefficients: thermal expansion coefficient and isothermal compressibility. The effects of the anion and of the length of the alkyl chain on the imidazolium ring on the volumetric properties were particularly examined. The mechanical coefficients were compared with those of common organic solvents, water and liquid NaCl. Finally, a prediction model, based on an "ideal" volumetric behavior of the ILs, is proposed to allow calculation of the molar volume of imidazolium-based ionic liquids as a function of temperature. ©2007 American Chemical Society.

Comments and Additional Work on “High-Pressure Volumetric Properties of Imidazolium-Based Ionic Liquids: Effect of the Anion”

This works follows a publication of our group in J. Chem. Eng. Data2007, 52, 2204–2211 presenting high temperature and pressure density data for five imidazolium-based ionic liquids. At this period, very few ionic liquid density data were available in the literature, especially at high pressure, and the uncertainty of published results was calculated with respect to the literature data available for three of the five ionic liquids studied. Since 2007, the ionic liquid density databank has largely increased. In this work, a comparison of our published data in J. Chem. Eng. Data2007, 52, 2204–2211, with more than 1800 high pressure data coming from the literature up to December 2011 is presented to assess the uncertainty of our published values. The claimed uncertainty is close to 0.31 % for all IL density data sets except in the case of the [C1C2Im][EtSO4], where the uncertainty is up to 1.1 %. Reported data in J. Chem. Eng. Data2007, 52, 2204–2211, for this particular ionic liquid cannot be used as a reference. For this ionic liquid, new density measurements of the same sample batch have been remeasured by using the same experimental technique, and new experimental data presented herein are clearly higher than our previous published results. A 1H NMR analysis of the sample has confirmed hydrolysis of the ethylsulfate anion to ethanol and hydrogenate anion which explains the differences observed between our density data and the literature.

Enhanced antimicrobial activities of 1-alkyl-3-methyl imidazolium ionic liquids based on silver or copper containing anions

We have developed a series of 1-alkyl-3-methylimidazolium tetrachlorocuprate(II) and dibromoargentate(I) ionic liquids with enhanced antimicrobial activity when compared with 1-alkyl-3-methylimidazolium chloride ionic liquids. These new ionic liquids proved to be effective against a range of pathogenic bacteria and fungi.

High pressure CO2 absorption studies on imidazolium-based ionic liquids:Experimental and simulation approaches

A combined experimental-computational study on the CO absorption on 1-butyl-3-methylimidazolium hexafluophosphate, 1-ethyl-3-methylimidazolium bis[trifluoromethylsulfonyl]imide, and 1-butyl-3-methylimidazolium bis[trifluoromethylsulfonyl]imide ionic liquids is reported. The reported results allowed to infer a detailed nanoscopic vision of the absorption phenomena as a function of pressure and temperature. Absorption isotherms were measured at 318 and 338K for pressures up to 20MPa for ultrapure samples using a state-of-the-art magnetic suspension densimeter, for which measurement procedures are developed. A remarkable swelling effect upon CO absorption was observed for pressures higher than 10MPa, which was corrected using a method based on experimental volumetric data. The experimental data reported in this work are in good agreement with available literature isotherms. Soave-Redlich-Kwong and Peng-Robinson equations of state coupled with bi-parametric van der Waals mixing rule were used for successful correlations of experimental high pressure absorption data. Molecular dynamics results allowed to infer structural, energetic and dynamic properties of the studied CO+ionic liquids mixed fluids, showing the relevant role of the strength of anion-cation interactions on fluid volumetric properties and CO absorption. © 2012 Elsevier B.V.

Viscous behavior of imidazolium-based ionic liquids

The viscosity of four imidazolium-based ionic liquids is analyzed as a function of pressure and temperature. Experimental measurements were carried out using an electromagnetic moving piston viscometer in the 303-353 K and 0.1-70 MPa ranges on synthesized ultrapure samples, and compared with available literature data. Molecular dynamics simulations were used to analyze the fluids' dynamic properties from a nanoscopic viewpoint, with special attention paid to self-diffusion coefficients and dynamic viscosity. Simulated properties are in excellent agreement with experimental results in spite of the glasslike dynamics of some of the studied fluids. © 2013 American Chemical Society.

Étude sur l'utilisation de liquides ioniques à base imidazolium pour l'extraction sélective de phosphopeptides

La phosphorylation des protéines constitue l’une des plus importantes modifications post-traductionnelles (PTMs) et intervient dans de multiples processus physiologiques tels, la croissance, la différenciation cellulaire, l’apoptose, etc. En dépit de son importance, l’analyse des phosphoprotéines demeure une tâche difficile en raison de leur nature dynamique (car la phosphorylation des protéines est un processus réversible) et de leur faible abondance relative. En effet, la détermination des sites de phosphorylation est souvent difficile car les phosphopeptides sont souvent difficiles à détecter par des méthodes d’analyse chromatographique classique et par spectrométrie de masse (MS). De récentes études ont démontré que les nombreuses méthodes d’enrichissement de phosphopeptides existantes ne sont pas complètes, et que le nombre total de phosphopeptides détectés ne chevauchent pas complètement ces méthodes. C’est pour cela qu’il existe une nécessité de combler les lacunes des méthodes d’enrichissement existantes afin d’avoir des analyses phosphoprotéomiques plus complètes. Dans cette étude, nous avons utilisé les liquides ioniques (LI), plus particulièrement les sels d’imidazolium, comme une technique d’enrichissement alternative, dans le but de favoriser une extraction sélective de phosphopeptides présents en solution. Les sels d’imidazolium ont donc été utilisés en raison de leurs propriétés physico-chimiques "facilement" ajustables selon la nature des substituants sur le noyau imidazolium et la nature de l’anion. Les sels de monoimidazolium et de bis-imidazolium possédant respectivement des chaînes linéaires à 4, 12 et 16 atomes de carbone et ayant différents anions ont été synthétisés et utilisés pour effectuer des extractions liquide-liquide et solide-liquide des phosphopeptides en solution. Dans un premier temps, des extractions liquide-liquide ont été réalisées en utilisant un liquide ionique (LI) ayant une chaine linéaire de 4 atomes de carbone. Ces extractions réalisées avec le bis(trifluoromethanesulfonyl) amide de 3-butyl-1-methylimidazolium (BMIM-NTf2) et l’hexafluorophosphate de 3-butyl-1-methylimidazolium (BMIM-PF6) n’ont pas montré une extraction notable du PPS comparativement au PN. Dans un deuxième temps, des extractions solide-liquide ont été réalisées en fonctionnalisant des particules solides avec des sels d’imidazolium possédant des chaines linéaires de 12 ou 16 atomes de carbone. Ces extractions ont été faites en utilisant un phosphopentapeptide Ac-Ile-pTyr-Gly-Glu-Phe-NH2 (PPS) en présence de 2 analogues acides non-phosphorylés. Il a été démontré que les sels d’imidazolium à chaine C12 étaient meilleurs pour extraire le PPS que les deux autres peptides PN (Ac-Ile-Tyr-Gly-Glu-Phe-NH2) et PE (Ac-Glu-Tyr-Gly-Glu-Phe-NH2) L’électrophorèse capillaire (CE) et la chromatographie liquide à haute performance couplée à la spectrométrie de masse (LC-MS) ont été utilisées pour quantifier le mélange des trois peptides avant et après extraction ; dans le but de mesurer la sélectivité et l’efficacité d’extraction de ces peptides par rapport à la composition chimique du liquide ionique utilisé.

Design, synthèse et application en catalyse verte d’un ligand alkyl imidazolium β-cyclodextrine

Le 21e siècle est le berceau d’une conscientisation grandissante sur les impacts environnementaux des processus utilisés pour synthétiser des molécules cibles. Parmi les avancées qui ont marqué ces dernières décennies, il est également question de réduction de déchets, de conservation de l’énergie et de durabilité des innovations. Ces aspects constituent les lignes directrices de la chimie verte. De ce fait, il est impératif de développer des stratégies de synthèse dont les impacts environnementaux sont bénins. Dans ce mémoire nous présentons la synthèse, la caractérisation et l’étude des propriétés catalytiques en milieu aqueux d’un ligand composé d’une unité -cyclodextrine native, d’une unité imidazolium et d’une chaine alkyle à 12 carbones. Ce ligand hybride s’auto-assemble dans l’eau sous forme de micelles, permettant ainsi d’effectuer en sa présence des couplages de Suzuki-Miyaura dans l’eau, avec de bons rendements. La fonctionnalisation de la face primaire de la -cyclodextrine par un noyau alkyl-imidazolium, précurseur de ligand de type carbène N-hétérocyclique, a permis le développement d’un système catalytique vert et hautement recyclable. Dans un deuxième temps, nous présentons l’utilisation du même ligand hybride dans des couplages de Heck dans l’eau, démontrant ainsi la versatilité du ligand.

Synthesis of multicarboxylic acid appended imidazolium ionic liquids and their application in palladium-catalyzed selective oxidation of styrene

A series of multicarboxylic acid appended imidazolium ionic liquids ( McaILs) with chloride [ Cl](-) or bromide [ Br](-) as anions have been synthesized and characterized. Deprotonation of these ionic acids gives the corresponding zwitterions. Re-protonation of the zwitterions with strong Bronsted acids gives a series of new ionic acid-adducts, many of which remained as room-temperature ionic liquids. A new catalytic system, McaIL/PdCl2 for the selective catalytic oxidation of styrene to acetophenone with hydrogen peroxide as an oxidant has been attempted. In the presence of McaILs, it is found that the quantity of palladium chloride PdCl2 used can be greatly reduced while the activity ( TOF) and selectivity towards acetophenone are enhanced sharply. It is also shown that the catalytic properties of this system could be finely tuned through the molecular design of the McaILs. The best TOF value obtained so far is 146 h(-1) with 100% conversion of styrene at 93% selectivity to acetophenone. In addition, the catalytic activity has been maintained for at least ten catalytic cycles.

Effect of SO(2) on the Transport Properties of an Imidazolium Ionic Liquid and Its Lithium Solution

Transport coefficients have been measured as a function of the concentration of sulfur dioxide, SO(2), dissolved in 1-butyl-2,3-dimethylimidazolium bis(trifluoromethylsulfonyl)-imide, [BMMI][Tf(2)N], as well as in its lithium salt solution, Li[Tf(2)N]. The SO(2) reduces viscosity and density and increases conductivity and diffusion coefficients in both the neat [BMMI] [Tf(2)N] and the [BMMI][Tf(2)N]-Li[Tf(2)N] solution. The conductivity enhancement is not assigned to a simple viscosity effect; the weakening of ionic interactions upon SO(2) addition also plays a role. Microscopic details of the SO(2) effect were unraveled using Raman spectroscopy and molecular dynamics (MD) simulations. The Raman spectra suggest that the Li(+)-[Tf(2)N] interaction is barely affected by SO(2), and the SO(2)-[Tf(2)N] interaction is weaker than previously observed in an investigation of an ionic liquid containing the bromide anion. Transport coefficients calculated by MD simulations show the same trend as the experimental data with respect to SO(2) content. The MD simulations provide structural information on SO(2) molecules around [Tf(2)N], in particular the interaction of the sulfur atom of SO(2) with oxygen and fluorine atoms of the anion. The SO(2)-[BMMI] interaction is also important because the [BMMI] cations with above-average mobility have a larger number of nearest-neighbor SO(2) molecules.

Application of 1-Allyl-3-(1-butyl)imidazolium Chloride in the Synthesis of Cellulose Esters: Properties of the Ionic Liquid, and Comparison with Other Solvents

The ionic liquid (IL), 1-allyl-3-(1-butyl)imidazolium chloride (AlBuImCl), has been synthesized and its properties determined. Increase in the temperature increased its conductivity and decreased its density, polarity, and viscosity. Microcrystalline cellulose (MCC), dissolves in thisIL by heating at 80 degrees C; this did not affect its degree of polymerization, decreased its index of crystallinity (Ic), and changed in morphology after regeneration. Convenient acylation of MCC was achieved by using 50% excess anhydride at 80 degrees C, for 24 or 48 h for acetic and butyric anhydride, respectively. The composition of the mixed esters depended on the initial ratio of the anhydrides, and their order of addition.

Raman spectra of acetonitrile in imidazolium ionic liquids

Raman spectra of dilute solutions of acetonitrile in ionic liquids reveal the characteristic features of ionic liquids` polarity. This is accomplished by investigating the Raman bandshape of the nu (CN) band, corresponding to the CN stretching mode of CH(3)CN, which is a very sensitive probe of the local environment. The amphiphilic nature of the CH(3)CN molecule allows us to observe the effect of electron pair acceptor and electron pair donor characteristics on ionic liquids. It has been found that the overall polarity of nine different ionic liquids based on 1-alkyl-3-methylimidazolium cations is more dependent on the anion than cation. The observed wavenumber shift of the nu (CN) band of CH(3)CN in ionic liquids containing alkylsulfate anions agrees with the significant different values previously measured for the dielectric constant of these ionic liquids. The conclusions obtained from the analysis of the nu (CN) band were corroborated by the analysis of the symmetric nu(1) (CD(3)) stretching mode of deuterated acetonitrile in different ionic liquids. Copyright (C) 2010 John Wiley & Sons, Ltd.

High Viscosity of Imidazolium Ionic Liquids with the Hydrogen Sulfate Anion: A Raman Spectroscopy Study

Ionic liquids based on 1-alkyl-3-methylimidazolium cations and the hydrogen sulfate (or bisulfate) anion, HSO4-, are much more viscous than ionic liquids with alkyl sulfates, RSO4-. The structural origin of the high viscosity of HSO4- ionic liquids is unraveled from detailed comparison of the anion Raman bands in 1-ethyl-3-methylimidazolium hydrogen sulfate and 1-butyl-3-methylimidazolium hydrogen sulfate with available data for simple HSO(4)(-) salts in crystalline phase, molten phase, and aqueous solution. Two Raman bands at 1046 and 1010 cm(-1) have been assigned as symmetric stretching modes nu(s)(S = O) of HSO4-, the latter being characteristic of chains of hydrogen-bonded anions. The intensity of this component increases in the supercooled liquid phase. For comparison purposes, Raman spectra of 1-ethyl-3-methylimidazolium ethyl sulfate and 1-butyl-3-methylimidazolium methyl sulfate have been also obtained. There is no indication of difference in the strength of hydrogen bond interactions of imidazolium cations with HSO4- or RSO4- anions. Raman spectra at high pressures, up to 2.6 GPa, are also discussed. Raman spectroscopy provides evidence that hydrogen-bonded anions resulting in anion-anion interaction is the reason for the high viscosity of imidazolium ionic liquids with HSO4-. If the ionic liquid is exposed to moisture, these structures are disrupted upon absorption of water from the atmosphere.

Synthesis and Characterization of the Europium(III) Pentakis(picrate) Complexes with Imidazolium Countercations: Structural and Photoluminescence Study

Six new lanthanide complexes of stoichiometric formula (C)(2)[Ln(Pic)(5)]-where (C) is a imidazolium cation coming from the ionic liquids 1-butyl-3-methylimidazolium picrate (BMIm-Pic), 1-butyl-3-ethylimidazolium picrate (BEIm-Pic), and 1,3-dibutylimidazolium picrate (BBIm-Pic), and Ln is Eu(III) or Gd(III) ions-have been prepared and characterized. To the best of our knowledge, these are the first cases of Ln(III) pentakis(picrate) complexes. The crystal structures of (BEIm)(2)[Eu(Pic)(5)] and (BBIm)(2)[Eu(Pic)(5)] compounds were determined by single-crystal X-ray diffraction. The [Eu(Pic)(5)](2-) polyhedra have nine oxygen atoms coordinated to the Eu(III) ion, four oxygen atoms from bidentate picrate, and one oxygen atom from monodentate picrate. The structures of the Eu complexes were also calculated using the sparkle model for lanthanide complexes, allowing an analysis of intramolecular energy transfer processes in the coordination compounds. The photoluminescence properties of the Eu(III) complexes were then studied experimentally and theoretically, leading to a rationalization of their emission quantum yields.

Synthesis and characterization of polymeric ionic liquid through free radical polymerization of acryloyl imidazolium-based ionic liquid monomer

This thesis investigates the synthesis of polymeric ionic liquid [(poly-acryloyloxy)6C6C1im][NTf2], by free radical polymerization of acryloyl imidazolium-base ionic liquid monomer [(acryloyloxy)6C6C1im][NTf2]. Moreover, the smartest synthetic route to obtain this monomer was investigated. Two different synthesis were compared. The first one started from the preparation of the monomer 6-chlorohexyl acrylate followed by substitution and metathesis to reach ionic liquid monomer. The second one started from synthesis of the ionic liquid [(HO)6C6C1im]Cl followed by metathesis and esterification in order to get ionic liquid monomer [(acryloyloxy)6C6C1im][NTf2].