Sample records for n-methyl-n-butyl pyrrolidinium bistrifluoromethane

  1. Study of a Li-air battery having an electrolyte solution formed by a mixture of an ether-based aprotic solvent and an ionic liquid

    NASA Astrophysics Data System (ADS)

    Cecchetto, Laura; Salomon, Mark; Scrosati, Bruno; Croce, Fausto


    Recent studies have clearly demonstrated that cyclic and linear carbonates are unstable when used in rechargeable Li-air batteries employing aprotic solvents mostly due to the cathodic formation of superoxide during the oxygen reduction reaction. In particular, it has been ascertained that nucleophilic attack by superoxide anion radical, O2-rad , at O-alkyl carbon is a common mechanism of decomposition of organic carbonates. Moreover, theoretical calculations showed that ether chemical functionalities are stable against nucleophilic substitution induced by superoxide. Aim of this study is to report on a new electrolyte solution for Li-air battery formed by a mixture of an ether-based aprotic solvent with an ionic liquid (IL). The IL-based electrolyte was obtained by mixing the pure ionic liquid N-methyl-(n-butyl) pyrrolidinium bis(trifluoromethane sulfonyl) imide (here denoted as PYR14TFSI) to a 0.91 M solution of lithium triflate (LiCF3SO3) in tetra ethylene glycol dimethyl etcher (TEGDME). We observed that the presence of IL beneficially affects the kinetics and the reversibility of the oxygen reactions involved at the cathode. The most significant result being a lower overvoltage for the charge reaction, compared to a Li/air cell containing the same electrolyte solution without IL.

  2. Physicochemical properties and toxicities of hydrophobicpiperidinium and pyrrolidinium ionic liquids

    SciTech Connect

    Salminen, Justin; Papaiconomou, Nicolas; Kumar, R. Anand; Lee,Jong-Min; Kerr, John; Newman, John; Prausnitz, John M.


    Some properties are reported for hydrophobic ionic liquids (IL) containing 1-methyl-1-propyl pyrrolidinium [MPPyrro]{sup +}, 1-methyl-1-butyl pyrrolidinium [MBPyrro]{sup +}, 1-methyl-1-propyl piperidinium [MPPip]{sup +}, 1-methyl-1-butyl piperidinium [MBPip]{sup +}, 1-methyl-1-octylpyrrolidinium [MOPyrro]{sup +} and 1-methyl-1-octylpiperidinium [MOPip]{sup +} cations. These liquids provide new alternatives to pyridinium and imidazolium ILs. High thermal stability of an ionic liquid increases safety in applications like rechargeable lithium-ion batteries and other electrochemical devices. Thermal properties, ionic conductivities, viscosities, and mutual solubilities with water are reported. In addition, toxicities of selected ionic liquids have been measured using a human cancer cell-line. The ILs studied here are sparingly soluble in water but hygroscopic. We show some structure-property relationships that may help to design green solvents for specific applications. While ionic liquids are claimed to be environmentally-benign solvents, as yet few data have been published to support these claims.

  3. Electropolymerization of poly(3-methylthiophene) in pyrrolidinium-based ionic liquids for hybrid supercapacitors

    Microsoft Academic Search

    Maurizio Biso; Marina Mastragostino; Maria Montanino; Stefano Passerini; Francesca Soavi


    The ionic liquids (ILs) N-butyl-N-methyl-pyrrolidinium trifluoromethanesulfonate (PYR14Tf) and N-methyl-N-propyl-pyrrolidinium bis(fluorosulfonyl)imide (PYR13FSI) are investigated as electropolymerization media for poly(3-methylthiophene) (pMeT) in view of their use in carbon\\/IL\\/pMeT hybrid supercapacitors. Data on the viscosity, solvent polarity, conductivity and electrochemical stability of PYR14Tf and PYR13FSI as well as the effect of their properties on the electropolymerization and electrochemical performance of pMeT, which features

  4. Halogenation Thermodynamics of Pyrrolidinium-Based Ionic Liquids

    E-print Network

    Chaban, Vitaly


    Room-temperature ionic liquids (RTILs) exhibit large difference between melting and boiling points. They are highly tunable thanks to numerous accessible combinations of the cation and the anion. On top of that, cations can be functionalized using methods of organic chemistry. This paper reports gas-phase thermodynamics (enthalpy, entropy, Gibbs free energy) of the halogenation reactions (fluorination, chlorination, bromination) involving protonated pyrrolidine C4H10N+, protic N-ethylpyrrolidinium C4H9N(C2H5)+, and aprotic N-ethyl-N-methylpyrrolidinium C4H8N(CH3)(C2H5)+ cations. Substitution of all symmetrically non-equivalent hydrogen atoms was compared based of the thermodynamic favorability. Fluorination of all sites is much more favorable than chlorination, whereas chlorination is somewhat more favorable than bromination. This is not trivial, since electronegative fluorine and chlorine have to compete for the already insufficient number of electrons with other atoms belonging to the pyrrolidinium-based ca...

  5. Nitrile-functionalized pyridinium, pyrrolidinium, and piperidinium ionic liquids.


    Lethesh, Kallidanthiyil Chellappan; Van Hecke, Kristof; Van Meervelt, Luc; Nockemann, Peter; Kirchner, Barbara; Zahn, Stefan; Parac-Vogt, Tatjana N; Dehaen, Wim; Binnemans, Koen


    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. PMID:21609018

  6. NMR investigation of ionic liquid-LiX mixtures: pyrrolidinium cations and TFSI- anions.


    Nicotera, Isabella; Oliviero, Cesare; Henderson, Wesley A; Appetecchi, Giovanni B; Passerini, Stefano


    In this paper is reported an extensive NMR characterization of N-methyl-N-propyl-pyrrolidinium bis(trifluoromethanesulfonyl)imide (PYR13TFSI) room-temperature ionic liquid and its mixtures with LiTFSI. NMR was used to investigate the interactions between the ionic liquid and lithium salt and the diffusion coefficients of all ionic species present in these mixtures. The results are compared with previous DSC, Raman, and electrochemical investigations. PMID:16853972

  7. Tuning the Properties of Functional Pyrrolidinium Polymers by (Co)polymerization of Diallyldimethylammonium Ionic Liquids.


    Jovanovski, V; Marcilla, R; Mecerreyes, David


    The synthesis and polymerization of novel diallyldimethylammonium ionic liquid monomers is described. A free-radical polymerization follows a ring-closing cyclopolymerization mechanism similar to the one observed previously for diallyldimethylammonium halides that leads to pyrrolidinium functional polymers. As previously observed in other families of polymeric ionic liquids, their physico-chemical properties are seriously affected by the nature of the counter-anion. As an example, the thermal stability increases following the trend SCN(-) ?

  8. Synthesis, growth, structural, thermal and optical studies of pyrrolidinium-2-carboxylate-4-nitrophenol single crystals.


    Swarna Sowmya, N; Sampathkrishnan, S; Vidyalakshmi, Y; Sudhahar, S; Mohan Kumar, R


    Organic nonlinear optical material, pyrrolidinium-2-carboxylate-4-nitrophenol (PCN) was synthesized and single crystals were grown by slow evaporation solution growth method. Single crystal X-ray diffraction analysis confirmed the structure and lattice parameters of PCN crystals. Infrared, Raman and NMR spectral analyses were used to elucidate the functional groups present in the compound. The thermal behavior of synthesized compound was studied by thermogravimetric and differential scanning calorimetry (TG-DSC) analyses. The photoluminescence property was studied by exciting the crystal at 360 nm. The relative second harmonic generation (SHG) efficiency of grown crystal was estimated by using Nd:YAG laser with fundamental wavelength of 1,064 nm. PMID:25795607

  9. A comprehensive study on micellization of dissymmetric pyrrolidinium headgroup-based gemini surfactants.


    Zou, Min; Dong, Jinfeng; Yang, Guangfu; Li, Xuefeng


    Three groups of pyrrolidinium headgroup-based gemini surfactants of 1,1'-(propane-1,3-diyl)bis(1-alkyl pyrrolidinium) bromide, in categories of symmetric CmC3CmPB (m = 10, 12, 14), dissymmetric CmC3C14PB (m = 10, 12, 14) and CmC3CnPB (m = 8, 10, 12, m + n = 24) surfactants, are studied using equilibrium surface tension, conductivity, fluorescence, and NMR techniques. The importance of the dissymmetry on the micellization has been revealed in detail. The increase in the hydrophobic chain length m for CmC3CmPB and CmC3C14PB or in the dissymmetry (n/m) for CmC3CnPB can strengthen the aggregation ability and surface activity of the surfactants significantly, i.e., a lower critical micelle concentration (cmc) and a lower surface tension at cmc (?cmc). However, the aggregation number at cmc (N*) obeys the opposite variation tendency and it becomes smaller upon increasing m or n/m, due to the formation of premicelles. Thermodynamic results reveal that the contribution of enthalpy (?H) to the Gibbs free energy (?G) is strengthened by increasing m or n/m during the spontaneous micellization process. Moreover, (1)H NMR results confirm the microenvironment change of the surfactants from polar water to micelles during the micellization, and 2D Noesy NMR spectra suggest that the methylene groups in the ring should adopt a conformation toward the nonpolar micellar core rather than in the polar water. PMID:25799507

  10. Systematic refinement of Canongia Lopes-Pádua force field for pyrrolidinium-based ionic liquids.


    Chaban, Vitaly V; Voroshylova, Iuliia V


    Reliable force field (FF) is a central issue in successful prediction of physical chemical properties via computer simulations. While Canongia Lopes-Pádua (CL&P) FF provides good to excellent thermodynamics and structure of pure room-temperature ionic liquids (RTILs), it suffers from drastically and systematically underestimated ionic motion. This occurs due to neglected partial electron transfer from the anion to the cation, resulting in unphysically small simulated self-diffusion and conductivity and high shear viscosities. We report a systematic refinement of the CL&P FF for six pyrrolidinium-based RTILs (1-N-butyl-1-methylpyrrolidinium dicyanamide, triflate, bis(fluorosulfonyl)imide, bis(trifluoromethanesulfonyl)imide, tetrafluoroborate, chloride). The elaborated procedure accounts for specific cation-anion interactions in the liquid phase. Once these interactions are described effectively, experimentally determined transport properties can be reproduced with an acceptable accuracy. Together with the original CL&P parameters, our force field fosters computational investigation of ionic liquids. In addition, the reported results shed more light on the chemical nature of cation-anion binding in various families of RTILs. PMID:25826190

  11. Effect of Titanium Substitution on the Compatiblity of Electrodeswith Pyrrolidinium-Based Ionic Liquid Electrolytes

    SciTech Connect

    Saint, Juliette A.; Shin, Joon-Ho; Best, Adam; Hollenkamp,Anthony; Kerr, John; Doeff, Marca M.


    The quest for the development of rechargeable lithium-metal batteries has attracted vigorous worldwide research efforts because this system offers the highest theoretical specific energy [1]. For this to be achieved, the repetitive deposition and stripping of lithium must be close to fully reversible. Thus, alternative electrolytes have been investigated, such as the room-temperature ionic liquid (RTILs). Lithium can be cycled with a high degree of reversibility with efficiencies exceeding 99% using systems based on N-methyl N-alkyl pyrrolidinium (P{sub 1X}{sup +}) combined with the TFSI anion [2]. More recent efforts have been directed towards systems based on P{sub 1X}{sup +} cations with the FSI anion and appear to be even more promising [3,4]. In this work, we discuss to what extent RTILs based on P{sub 1X}{sup +} cations with TFSI or FSI anions can be used as electrolytes for rechargeable Li batteries. In particular, their physical and chemical properties are thoroughly discussed so as to explain the difference observed in their electrochemical behavior. Although these two systems seem to be stable against lithium, their compatibilities with cathode materials require full assessment as well. Thus, various manganese oxide cathodes are investigated in this study. Strategies to minimize cathode dissolution are also debated, such as the substitution of part of the manganese for titanium.

  12. Physico-Chemical Properties and Phase Behaviour of Pyrrolidinium-Based Ionic Liquids

    PubMed Central

    Doma?ska, Urszula


    A review of the relevant literature on 1-alkyl-1-methylpyrrolidinium-based ionic liquids has been presented. The phase diagrams for the binary systems of {1-ethyl-1-methylpyrrolidinium trifluoromethanesulfonate (triflate) [EMPYR][CF3SO3] + water, or + 1-butanol} and for the binary systems of {1-propyl-1-methylpyrrolidinium trifluoromethanesulfonate (triflate) [PMPYR][CF3SO3] + water, or + an alcohol (1-butanol, 1-hexanol, 1-octanol, 1-decanol)} have been determined at atmospheric pressure using a dynamic method. The influence of alcohol chain length was discussed for the [PMPYR][CF3SO3]. A systematic decrease in the solubility was observed with an increase of the alkyl chain length of an alcohol. (Solid + liquid) phase equilibria with complete miscibility in the liquid phase region were observed for the systems involving water and alcohols. The solubility of the ionic liquid increases as the alkyl chain length on the pyrrolidinium cation increases. The correlation of the experimental data has been carried out using the Wilson, UNIQUAC and the NRTL equations. The phase diagrams reported here have been compared to the systems published earlier with the 1-alkyl-1-methylpyrrolidinium-based ionic liquids. The influence of the cation and anion on the phase behaviour has been discussed. The basic thermal properties of pure ILs, i.e., melting temperature and the enthalpy of fusion, the solid-solid phase transition temperature and enthalpy have been measured using a differential scanning microcalorimetry technique. PMID:20480044

  13. Interionic interactions of binary gels consisting of pyrrolidinium-based zwitterionic compounds and lithium salts.


    Park, HoSeok; Kim, Hoon Sik; Jung, Young Mee


    We demonstrated thermal transitions and physical gelation of binary ionic salts through interionic interactions, which consist of pyrrolidinium-N-propanesulfonate zwitterionic compound (PyrZIC) and lithium bis(trifluorosulfonyl)imide (LiTFSI). The transition behaviors of binary ionic gels were attributed to conformational changes in the cations and anions of PyrZIC and LiTFSI as analyzed by density functional theory (DFT), principal component analysis (PCA), and two-dimensional infrared correlation spectroscopy (2D IR COS). Furthermore, the geometries of binary PyrZIC-LiTFSI systems were strongly influenced by the electrostatic interactions between two ionic salts. The different dynamic processes in the PyrZIC- and LiTFSI-rich phases, which are classified by the transition point of PCA plots, were induced by the conformational changes in the respective interaction fields, as shown by 2D correlation spectra. In particular, LiTFSI-rich binary gels revealed characteristic four-leaf-clover and butterfly patterns under their unique chemical circumstances, which were different from those of PyrZIC-rich gels. Consequently, these computational and experimental investigations provide an analytical tool to understand the physical phenomenon and interactions occurring in the unveiled and complicated systems. PMID:21291183

  14. Stable, High-Efficiency Pyrrolidinium-Based Electrolyte for Solid-State Dye-Sensitized Solar Cells.


    He, Tong; Wang, Ye Feng; Zeng, Jing Hui


    We synthesized a series of pyrrolidinium based dicationic ionic crystals with high melting point and good thermal stability. Research on the crystal structure shows that there are ordered three-dimensional ionic channels in these crystals which is favorable for the ionic conductor to achieve high conductivity and diffusion coefficient. These ionic crystals are applied to electrolyte as matrix in dye sensitized solar cells, and the influence of crystal structure (including the alkylene chain separating two pyrrolidinium rings and anion) versus the device performances are studied by steady-state voltammography, current-voltage trace, and electrochemical impedance spectroscopy. As the solid state electrolyte, an optimized efficiency of 6.02% have achieved under full sunlight irradiation using ionic crystal [C6BEP][TFSI]2. And the device based on this solid electrolyte shows the excellent long-term stability, maintaining 92% of the initial efficiency after 960 h. This study elucidates fundamental the structure of dicationic crystal and provide useful clues for further improvement of solid-state electrolytes in DSSC. PMID:26336080

  15. Effect of chemical modification on the ability of pyrrolidinium fullerene to induce apoptosis of cells transformed by JAK2 V617F mutant.


    Funakoshi-Tago, Megumi; Tsukada, Masaki; Watanabe, Toshiro; Mameda, Yuka; Tago, Kenji; Ohe, Tomoyuki; Nakamura, Shigeo; Mashino, Tadahiko; Kasahara, Tadashi


    JAK2 V617F mutant, a gene responsible for human myeloproliferative neoplasms (MPNs), causes not only cellular transformation but also resistance to various anti-cancer drugs. We previously reported that pyrrolidinium fullerene markedly induced the apoptosis of JAK2 V617F mutant-induced transformed cells through the reduction of apoptosis signal-regulating kinase 1 (ASK1), following inhibition of the c-Jun N-terminal kinase (JNK) pathway. In the current study, we found that the replacement of the 2-hydrogen atom (H) or N-methyl group (CH3) by the butyl group (C4C9) caused the more than 3-fold potent cytotoxic effects on cells transformed by the JAK2 V617F mutant. Strikingly, these chemical modification of pyrrolidinium fullerene resulted in more marked reduction of ASK1 protein and a more potent inhibitory effect on the JNK signaling cascade. On the other hand, when modified with a longer alkyl group, the derivatives lacked their cytotoxicity. These observations clearly indicate that the modification of pyrrolidinium fullerene with a suitable length of alkyl group such as butyl group enhances its apoptotic effect through inhibition of the ASK1-MKK4/7-JNK pathway. PMID:24631513

  16. Growth of Gold Nanosheets and Nanopolyhedra in Pyrrolidinium-Based Ionic Liquids: Investigation of the Cation Effect on the Resulting Morphologies

    SciTech Connect

    Bouvy, Claire; Baker, Gary A; Yin, Hongfeng; Dai, Sheng


    Large gold nanosheets and small gold polyhedra have been successfully synthesized in room-temperature ionic liquids (ILs) by an ionothermal reduction of HAuCl{sub 4} under N{sub 2} atmosphere, without using any additives. The effect of the organic cation on the final morphologies of the gold particles has been studied, and a series of pyrrolidinium-, imidazolium-, and quaternary amine-based ionic liquids have been investigated by scanning electron microscopy (SEM) and X-ray diffraction (XRD) measurements. Our results show that these ILs favor the anisotropic growth of gold by acting as template agents and that only gold microspheres can be obtained with the IL containing a reductive functionality.

  17. Liquid structure and conformation of a low-viscosity ionic liquid, N-methyl- N-propyl-pyrrolidinium bis(fluorosulfonyl) imide studied by high-energy X-ray scattering

    Microsoft Academic Search

    Kenta Fujii; Shiro Seki; Shuhei Fukuda; Toshiyuki Takamuku; Shinji Kohara; Yasuo Kameda; Yasuhiro Umebayashi; Shin-ichi Ishiguro


    Liquid structure of a low-viscosity ionic liquid, N-methyl-N-propyl- pyrrolidinium bis(fluorosulfonyl) imide (P13+FSI?) has been studied by a high-energy X-ray scattering technique at 298 K. The radial distribution function (RDF) indicates that the ionic liquid involves an ordered structure with significant intermolecular interactions at around 6, 10 and 16 Å. In order to obtain information of intermolecular interactions in the range r<6 Å, where

  18. Pentaborate(1-) salts templated by substituted pyrrolidinium cations: synthesis, structural characterization, and modelling of solid-state H-bond interactions by DFT calculations.


    Beckett, Michael A; Coles, Simon J; Davies, R Andrew; Horton, Peter N; Jones, Charlotte L


    The synthesis and characterization of a series of pentaborate(1-) salts of substituted pyrrolidinium cations [C4H8NH2][B5O6(OH)4] (), [C4H8NMe2][B5O6(OH)4] () [C4H8NMeH][B5O6(OH)4] (), [(2-CH2OH)C4H7NH2][B5O6(OH)4] () is reported. All compounds were characterized by single-crystal XRD studies with (1/2CH3COCH3) and (1/2H2O) solvated. TGA/DSC analysis of the pentaborates showed that they thermally decomposed in air at 800 °C to 2.5 B2O3, in a 2 step process involving dehydration (<250 °C) and oxidative decomposition (250-600 °C). BET analysis of materials derived thermally from the pentaborates and had internal porosities of <1 m(2) g(-1), indicating they were non-porous. All compounds show extensive supramolecular H-bonded anionic lattices. H-bond interactions are described in detail and motifs found in these and in other pentaborate structures have been examined and modelled by DFT calculations. These calculations confirm that H-bonds interactions in pentaborates are moderately strong (ca. -10 to -21 kJ mol(-1)) and are likely to dominate the energetics of their templated syntheses. PMID:25785672

  19. Structure and properties of Li-ion conducting polymer gel electrolytes based on ionic liquids of the pyrrolidinium cation and the bis(trifluoromethanesulfonyl)imide anion

    NASA Astrophysics Data System (ADS)

    Pitawala, Jagath; Navarra, Maria Assunta; Scrosati, Bruno; Jacobsson, Per; Matic, Aleksandar


    We have investigated the structure and physical properties of Li-ion conducting polymer gel electrolytes functionalized with ionic liquid/lithium salt mixtures. The membranes are based on poly(vinylidene fluoride-co-hexafluoropropylene) copolymer, PVdF-HFP, and two ionic liquids: pyrrolidinium cations, N-butyl-N-methylpyrrolidinium (PyR14+), N-butyl-N-ethylpyrrolidinium (PyR24+), and bis(trifluoromethanesulfonyl)imide anion (TFSI). The ionic liquids where doped with 0.2 mol kg--1 LiTFSI. The resulting membranes are freestanding, flexible, and nonvolatile. The structure of the polymer and the interactions between the polymer and the ionic liquid electrolyte have been studied using Raman spectroscopy. The ionic conductivity of the membranes has been studied using dielectric spectroscopy whereas the thermal properties were investigated using differential scanning caloriometry (DSC). These results show that there is a weak, but noticeable, influence on the physical properties of the ionic liquid by the confinement in the membrane. We observe a change in the Li-ion coordination, conformation of the anion, the fragility and a slight increase of the glass transition temperatures for IL/LiTFSI mixtures in the membranes compared to the neat mixtures. The effect can be related to the confinement of the liquid in the membrane and/or to interactions with the PVdF-HFP polymer matrix where the crystallinity is decreased compared to the starting polymer powder.

  20. Analysis of the solid electrolyte interphase formed with an ionic liquid electrolyte for lithium-sulfur batteries

    NASA Astrophysics Data System (ADS)

    Xiong, Shizhao; Xie, Kai; Blomberg, Erik; Jacobsson, Per; Matic, Aleksandar


    We have investigated the formation of the solid electrolyte interphase (SEI) on lithium electrodes in the presence of an ionic liquid electrolyte with a particular focus on the influence of polysulfides present in the electrolyte on the SEI. The electrochemical performance of symmetric cells with lithium electrodes and electrolytes composed of N-Methyl-(n-butyl)pyrrolidinium bis(trifluoromethanesulfonyl)imide (PYR14-TFSI) and LiTFSI, with and without the addition of polysulfides, were analyzed as well as the chemical composition of the SEI, before and after cycling. The cycling behavior of the symmetrical cells shows that the SEI films are relatively stable in the ionic liquid electrolyte, also in the presence of polysulfides. However, the presence of polysulfides results in a higher SEI layer resistance (RSEI) and a higher activation energy. From X-ray photoelectron spectroscopy spectra (XPS), with argon-ion sputtering for depth profiling, we find that the SEI is formed by decomposition products from both cations and anions of the electrolyte. The XPS spectra show that the presence of polysulfides alters the decomposition process of the electrolyte, resulting in a SEI film with different chemical composition and structure, in line with the results from the electrochemical performance.

  1. Homogeneous lithium electrodeposition with pyrrolidinium-based ionic liquid electrolytes.


    Grande, Lorenzo; von Zamory, Jan; Koch, Stephan L; Kalhoff, Julian; Paillard, Elie; Passerini, Stefano


    In this study, we report on the electroplating and stripping of lithium in two ionic liquid (IL) based electrolytes, namely N-butyl-N-methylpyrrolidinium bis(fluorosulfonyl) imide (Pyr14FSI) and N-butyl-N-methylpyrrolidinium bis(trifluoromethanesulfonyl)imide (Pyr14TFSI), and mixtures thereof, both on nickel and lithium electrodes. An improved method to evaluate the Li cycling efficiency confirmed that homogeneous electroplating (and stripping) of Li is possible with TFSI-based ILs. Moreover, the presence of native surface features on lithium, directly observable via scanning electron microscope imaging, was used to demonstrate the enhanced electrolyte interphase (SEI)-forming ability, that is, fast cathodic reactivity of this class of electrolytes and the suppressed dendrite growth. Finally, the induced inhomogeneous deposition enabled us to witness the SEI cracking and revealed previously unreported bundled Li fibers below the pre-existing SEI and nonrod-shaped protuberances resulting from Li extrusion. PMID:25714124

  2. Communication: X-ray Scattering from Ionic Liquids with Pyrrolidinium Cations

    SciTech Connect

    C Santos; N Murthy; G Baker; E Castner


    We report the structure functions obtained from x-ray scattering experiments on a series of four homologous ionic liquids. The ionic liquids are 1-alkyl-1-methylpyrrolidinium cations paired with the bis(trifluoromethylsulfonyl)amide anion, with alkyl chain lengths of n = 4, 6, 8, and 10. The structure functions display two intense diffraction peaks for values of the scattering vector q in the range from 0.6 to 1.5 {angstrom}{sup -1} for all samples. Both diffraction peaks shift to lower values of q for increasing temperature. First sharp diffraction peaks are observed in the structure functions for q < 0.5 {angstrom}{sup -1} for liquids with n = 6, 8, and 10.

  3. Influence of Zn2+ and water on the transport properties of a pyrrolidinium dicyanamide ionic liquid.


    Simons, T J; Bayley, P M; Zhang, Z; Howlett, P C; MacFarlane, D R; Madsen, L A; Forsyth, M


    In order to expand our understanding of a potential zinc-based battery electrolyte, we have characterized the physical and transport properties of the ionic liquid (IL) 1-butyl-1-methylpyrrolidinium dicyanamide ([C4mpyr][dca]) containing various levels of both Zn(2+) and H2O. Detailed measurements of density, viscosity, conductivity, and individual anion and cation diffusion coefficients using pulsed-field-gradient (PFG) NMR combined with NMR chemical shifts and spin-lattice relaxation (T1) NMR experiments provide insights into the motion and chemical environment of all molecular species. We find that the various techniques for probing ion transport and dynamics form a coherent picture as a function of electrolyte composition. Zn(2+) addition causes a moderate reduction in the self-diffusion of the IL anion and cation, whereas the addition of H2O increases ion mobility by increasing the liquid's overall fluidity. Temperature-dependent (13)C T1 experiments of the dca carbon analyzed using Bloembergen-Purcell-Pound fits show monotonic slowing of anion dynamics with Zn(2+) addition, suggesting increased Zn(2+)/dca(-) association. T1 experiments show minimal change in the spin-lattice relaxation of cation or anion upon H2O addition, suggesting that H2O is playing no significant role in Zn(2+) speciation. Finally, we employ a novel electrophoretic NMR technique to directly determine the electrophoretic mobility of the C4mpyr cation, which we discuss in the context of impedance-based conductivity measurements. PMID:24712560

  4. Effect of pyrrolidinium based ionic liquid on the channel form of gramicidin in lipid vesicles.


    Singh, Upendra Kumar; Dohare, Neeraj; Mishra, Prabhash; Singh, Prashant; Bohidar, Himadri B; Patel, Rajan


    The present work is focused on the interaction between membrane bound gramicidin and 1-butyl-1-methyl-2-oxopyrrolidinium bromide (BMOP) ionic liquid. Ionic liquids (ILs) are solvents that are often liquid at room temperature and composed of organic cation and appropriate anion. The gramicidin peptide forms prototypical ion channels for cations, which have been extensively used to study the organization, dynamics, and function of membrane spanning channels. The interaction was studied by circular dichroism, steady state, time-resolved fluorescence spectroscopy in combination with dynamic surface tension and field emission scanning electron microscopic methods (FESEM). The results obtained from circular dichroism shows that the BMOP interacts with the channel form of gramicidin in lipid vesicle without any considerable effect on its conformation. The Red-edge excitation shift (REES) also supported the above findings. In addition, the fluorescence studies suggested that BMOP makes ground state complex with ion channel, which was further supported by time resolved measurements. Furthermore, dynamic surface tension analysis shows the faster adsorption of BMOP with membrane bound gramicidin at the air-water interface. Additionally, FESEM results indicated that BMOP forms a film around the membrane bound gramicidin at higher concentration. These results are potentially useful to analyze the effect of ionic liquids on the behaviour of membrane proteins. PMID:26025771

  5. Combined Measurement of Translational and Rotational Diffusion in Quaternary Acyclic Ammonium and Cyclic Pyrrolidinium Ionic

    E-print Network

    devices, use in CO2 capture, and as green solvents.1-5 Understanding the transport properties as well as the ionic and solvent interactions of ILs is important for predicting their physicochemical properties.6,18 or deviations from the SE and SED relation- ships.19 The SE and SED breakdown is most commonly attributed

  6. Influence of Solute Charge and Pyrrolidinium Ionic Liquid Alkyl Chain Length on Probe Rotational Reorientation Dynamics

    SciTech Connect

    Guo, Jianchang; Mahurin, Shannon Mark; Baker, Gary A; Hillesheim, Patrick C; Dai, Sheng; Shaw, Robert W


    In recent years, the effect of molecular charge on the rotational dynamics of probe solutes in room temperature ionic liquids (RTILs) has been a subject of growing interest. For the purpose of extending our understanding of charged solute behavior within RTILs, we have studied the rotational dynamics of three illustrative xanthene fluorescent probes within a series of N-alkylpyrrolidinium bis(trifluoromethylsulfonyl)imide ([Cnmpyr][Tf2N]) RTILs with different n-alkyl chain lengths (n = 3, 4, 6, 8, or 10) using time-resolved fluorescence anisotropy decay. The rotational dynamics of the neutral probe rhodamine B dye lies between the stick and slip boundary conditions due to the influence of specific hydrogen bonding interactions. The rotation of the negatively-charged sulforhodamine 640 is slower than that of its positively-charged counterpart rhodamine 6G. An analysis based upon Stokes-Einstein-Debye hydrodynamics indicates that SR640 adheres to stick boundary conditions due to specific interactions, whereas the faster rotation of R6G is attributed to weaker electrostatic interactions. No dependence of the rotational dynamics on the solvent alkyl chain length was observed for any of the three dyes, suggesting that the specific interactions between dyes and RTILs are independent of this solvent parameter.

  7. Simultaneous separation of acidic and basic proteins using gemini pyrrolidinium surfactants and hexafluoroisopropanol as dynamic coating additives in capillary electrophoresis.


    Tian, Yu; Li, Yunfang; Mei, Jie; Cai, Bo; Dong, Jinfeng; Shi, Zhiguo; Xiao, Yuxiu


    The separation of acidic and basic proteins using CE has been limited in part due to the adsorption of proteins onto the capillary wall. In this work, the efficient control of EOF and the simultaneous separation of acidic and basic proteins are achieved by use of C18-4-C18PB as a dynamic coating additive, which is a representative surfactant for 1,1'-(butane-1,s-alkyl)bis(1-alkylpyrrolidinium) bromide (Cn-4-CnPB, n=10, 12, 14, 16 and 18). C18-4-C18PB exhibits a powerful capability in the reversal of EOF, and a low concentration even less than 0.001mM is sufficient to reverse EOF at the tested pH values (3.0-9.0). Baseline separation of eight proteins with sharp peaks and high efficiencies (54,000-297,000 plates/m) is obtained with 30mM NaH2PO4 buffer (pH 5.0) containing 4mM C18-4-C18PB. At the same buffer condition, the Cn-4-CnPB with shorter alkyl chain (n=10, 12, 14, 16) cannot achieve the same effective protein separation as C18-4-C18PB. However, the combined use of small amounts (?0.5%, v/v) of hexafluoroisopropanol (HFIP) and Cn-4-CnPB (n=10, 12, 14, 16) as additives can completely separate all eight proteins with high efficiencies of 81,000-318,000 plates/m. The RSDs of migration time are less than 0.80% and 5.84% for run-to-run and day-to-day assays (n=5), respectively, and the protein recoveries are larger than 90.15%. To the best of our knowledge, this is the first report on the simultaneous separation of acidic and basic proteins using Cn-4-CnPB surfactants or Cn-4-CnPB surfactants combined with HFIP as dynamic coating additives. PMID:26300480

  8. ‘Bucky gel’ of multiwalled carbon nanotubes as electrodes for high performance, flexible electric double layer capacitors

    NASA Astrophysics Data System (ADS)

    Singh, Manoj K.; Kumar, Yogesh; Hashmi, S. A.


    We report the preparation of a gelled form of multiwalled carbon nanotubes (MWCNTs) with an ionic liquid 1-butyl-1-methyl pyrrolidinium bis(trifluoromethane sulfonyl)imide (BMPTFSI)), referred to as ‘bucky gel’, to be used as binderless electrodes in electrical double layer capacitors (EDLCs). The characteristics of gelled MWCNTs are compared with pristine MWCNTs using transmission electron microscopy, x-ray diffraction and Raman studies. A gel polymer electrolyte film consisting of a blend of poly(vinylidene fluoride-co-hexafluoropropylene) and BMPTFSI, exhibiting a room temperature ionic conductivity of 1.5 × 10-3 S cm-1, shows its suitability as an electrolyte/separator in flexible EDLCs. The performance of EDLCs, assembled with bucky gel electrodes, using impedance spectroscopy, cyclic voltammetry and charge-discharge analyses, are compared with those fabricated with pristine MWCNT-electrodes. An improvement in specific capacitance (from 19.6 to 51.3 F g-1) is noted when pristine MWCNTs are replaced by gelled MWCNT-binderless electrodes. Although the rate performance of the EDLCs with gelled MWCNT-electrodes is reduced, the pulse power of the device is sufficiently high (˜10.5 kW kg-1). The gelled electrodes offer improvements in energy and power densities from 2.8 to 8.0 Wh kg-1 and 2.0 to 4.7 kW kg-1, respectively. Studies indicate that the gel formation of MWCNTs with ionic liquid is an excellent route to obtain high-performance EDLCs.

  9. Phase behavior and ionic conductivity in lithium bis(trifluoromethanesulfonyl)imide-doped ionic liquids of the pyrrolidinium cation and Bis(trifluoromethanesulfonyl)imide anion.


    Martinelli, Anna; Matic, Aleksandar; Jacobsson, Per; Börjesson, Lars; Fernicola, Alessandra; Scrosati, Bruno


    The phase behavior and the ionic conductivity of ionic liquids (ILs) of the N-alkyl-N-alkylpyrrolidinium (PYR(xy)) cation and the bis(trifluoromethanesulfonyl)imide (TFSI) anion are investigated upon addition of LiTFSI salt. We compare the case of two new ILs of the PYR(2y) cation (where 2 is ethyl and y is butyl or propyl) with that of the PYR(14) (where 1 is methyl and 4 is butyl). We find that the addition of LiTFSI increases the glass transition temperature, decreases the melting temperature and the heat of fusion and, in the ILs of the PYR(2y) family, suppresses crystallization. In the solid state, significant ionic conductivities are found, being as high as 10(-5) S cm(-1), strongly increasing with Li(+) concentration. The opposite trend is found in the liquid state, where the conductivity is on the order of 10(-3)-10(-2) S cm(-1) at room temperature. A T(g)-scaled Arrhenius plot shows that the liquid-state ionic conductivity in these systems is mainly governed by viscosity and that the fragility of the liquids is slightly influenced by the structural modifications on the cation. PMID:19621942

  10. Fullerene derivative prevents cellular transformation induced by JAK2 V617F mutant through inhibiting c-Jun N-terminal kinase pathway.


    Funakoshi-Tago, Megumi; Nagata, Tatsuaki; Tago, Kenji; Tsukada, Masaki; Tanaka, Kazuyuki; Nakamura, Shigeo; Mashino, Tadahiko; Kasahara, Tadashi


    The constitutively activated mutation (V617F) of tyrosine kinase Janus kinase 2 (JAK2) is found in the majority of patients with myeloproliferative neoplasms (MPNs). The development of a novel chemical compound to suppress JAK2 V617F mutant-induced onset of MPNs and clarification of the signaling cascade downstream of JAK2 V617F mutant will provide clues to treat MPNs. Here we found that a water-soluble pyrrolidinium fullerene derivative, C(60)-bis (N, N-dimethylpyrrolidinium iodide), markedly induced apoptosis of JAK2 V617F mutant-induced transformed cells through a novel mechanism, inhibiting c-Jun N-terminal kinase (JNK) activation pathway but not generation of reactive oxygen species (ROS). Pyrrolidinium fullerene derivative significantly reduced the protein expression level of apoptosis signal-regulating kinase 1 (ASK1), one of the mitogen-activated protein kinase kinase kinases (MAPKKK), resulting in the inhibition of upstream molecules of JNK, mitogen-activated protein kinase kinase 4 (MKK4) and mitogen-activated protein kinase kinase 7 (MKK7). Strikingly, the knockdown of ASK1 enhanced the sensitivity to pyrrolidinium fullerene derivative-induced apoptosis, and the treatment with a JNK inhibitor, SP600125, also induced apoptosis of the transformed cells by JAK2 V617F mutant. Furthermore, administration of both SP600125 and pyrrolidinium fullerene derivative markedly inhibited JAK2 V617F mutant-induced tumorigenesis in nude mice. Taking these findings together, JAK2 V617F mutant-induced JNK signaling pathway is an attractive target for MPN therapy, and pyrrolidinium fullerene derivative is now considered a candidate potent drug for MPNs. PMID:22750290

  11. Synthesis of Organic (Trimethylsilyl)chalcogenolate Salts Cat[TMS-E] (E = S, Se, Te): the Methylcarbonate Anion as a Desilylating Agent.


    Finger, Lars H; Scheibe, Benjamin; Sundermeyer, Jörg


    A high-yield synthesis of the class of (trimethylsilyl)chalcogenolate organic salts [Cat][TMS-E] (E = S, Se, Te; Cat = BMPyr, DMPyr, NMe4, nBu3MeP) is presented. The title compounds have been prepared by the strictly aprotic reaction between the respective bis(trimethylsilyl)chalcogenide (TMS2E) and methylcarbonate ionic liquids (ILs). This constitutes a novel reaction behavior of methylcarbonate ILs, acting as a nucleophilic desilylating agent and a Lewis base instead of as a Brønsted base. Thus prepared silylchalcogenolate salts represent an activated form of the multifunctional TMS2E reactant series. Pyrrolidinium TMS-S salts have proven to be excellent precursors for the synthesis of pyrrolidinium hexasulfides. The scope of the desilylation reaction can be extended to other silyl-bearing synthons such as (trimethylsilyl)azide and (trimethylsilyl)cyanide. PMID:26371537

  12. Room Temperature Ionic Liquids for Separating Organics from Produced Water

    Microsoft Academic Search

    J. McFarlane; W. B. Ridenour; H. Luo; R. D. Hunt; D. W. DePaoli; R. X. Ren


    The distribution of polar organic compounds typical of water contaminants (organic acids, alcohols, and aromatic compounds) associated with oil and gas production was measured between water and nine hydrophobic, room?temperature ionic liquids. The ionic liquids used in this study were 1?butyl?3?methylimidazolium bistrifluoromethanesulfonylimide, 1?hexyl?3?methylimidazolium bistrifluoromethanesulfonylimide, 1?octyl?3?methylimidazolium bistrifluoromethanesulfonylimide, 1?butyl?3?methylimidazolium hexafluorophosphate, trihexyltetradecylphosphonium bistrifluoromethanesulfonylimide, 1?butyl?1?methyl?pyrrolidinium bistrifluoromethanesulfonylimide, trihexyltetradecylphosphonium dodecylbenzenesulfonate, tributyltetradecylphosphonium dodecylbenzenesulfonate, and trihexyltetradecylphosphonium methanesulfonate. Sensitivity

  13. Ionic liquids based on (fluorosulfonyl)(pentafluoroethanesulfonyl)imide with various oniums

    Microsoft Academic Search

    Kai Liu; Yi-Xuan Zhou; Hong-Bo Han; Si-Si Zhou; Wen-Fang Feng; Jin Nie; Hong Li; Xue-Jie Huang; Michel Armand; Zhi-Bin Zhou


    New hydrophobic ionic liquids based on (fluorosulfonyl)(pentafluoroethanesulfonyl)imide ([(FSO2)(C2F5SO2)N]?, FPFSI?) anion with various oniums, including imidazolium, tetraalkyl ammonium, pyrrolidinium, and piperidinium, were prepared and characterized. Their physicochemical and electrochemical properties, including phase transitions, thermal stability, viscosity, density, specific conductivity and electrochemical windows, were extensively characterized, and were comparatively studied with the corresponding ionic liquids containing the isomeric but symmetric TFSI? ([(CF3SO2)2N]?)

  14. Lithium-sulfur batteries based on nitrogen-doped carbon and ionic liquid electrolyte

    SciTech Connect

    Sun, Xiao-Guang [ORNL; Wang, Xiqing [ORNL; Mayes, Richard T [ORNL; Dai, Sheng [ORNL


    Nitrogen-doped mesoporous carbon (NC) and sulfur were used to prepare an NC/S composite cathode, which was evaluated in an ionic liquid electrolyte of 0.5 M lithium bis(trifluoromethane sulfonyl)imide (LiTFSI) in methylpropylpyrrolidinium bis(trifluoromethane sulfonyl)imide (MPPY.TFSI) by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and cycle testing. To facilitate the comparison, a C/S composite based on activated carbon (AC) without nitrogen doping was also fabricated under the same conditions as those for the NC/S composite. Compared with the AC/S composite, the NC/S composite showed enhanced activity toward sulfur reduction, as evidenced by the early onset sulfur reduction potential, higher redox current density in the CV test, and faster charge transfer kinetics as indicated by EIS measurement. At room temperature under a current density of 84 mA g-1 (C/20), the battery based on the NC/S composite exhibited higher discharge potential and an initial capacity of 1420 mAh g-1 whereas that based on the AC/S composite showed lower discharge potential and an initial capacity of 1120 mAh g-1. Both batteries showed similar capacity fading with cycling due to the intrinsic polysulfide solubility and the polysulfide shuttle mechanism; the capacity fading can be improved by further modification of the cathode.

  15. Lithium-sulfur batteries based on nitrogen-doped carbon and an ionic-liquid electrolyte.


    Sun, Xiao-Guang; Wang, Xiqing; Mayes, Richard T; Dai, Sheng


    Nitrogen-doped mesoporous carbon (NC) and sulfur were used to prepare an NC/S composite cathode, which was evaluated in an ionic-liquid electrolyte of 0.5 M lithium bis(trifluoromethane sulfonyl)imide (LiTFSI) in methylpropylpyrrolidinium bis(trifluoromethane sulfonyl)imide ([MPPY][TFSI]) by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and cycle testing. To facilitate the comparison, a C/S composite based on activated carbon (AC) without nitrogen doping was also fabricated under the same conditions. Compared with the AC/S composite, the NC/S composite showed enhanced activity toward sulfur reduction, as evidenced by the lower onset sulfur reduction potential, higher redox current density in the CV test, and faster charge-transfer kinetics, as indicated by EIS measurements. At room temperature under a current density of 84 mA g(-1) (C/20), the battery based on the NC/S composite exhibited a higher discharge potential and an initial capacity of 1420 mAh g(-1), whereas the battery based on the AC/S composite showed a lower discharge potential and an initial capacity of 1120 mAh g(-1). Both batteries showed similar capacity fading with cycling due to the intrinsic polysulfide solubility and the polysulfide shuttle mechanism; capacity fading can be improved by further cathode modification. PMID:22847977

  16. Highly selective separation of carbon dioxide from nitrogen and methane by nitrile/glycol-difunctionalized ionic liquids in supported ionic liquid membranes (SILMs).


    Hojniak, Sandra D; Silverwood, Ian P; Khan, Asim Laeeq; Vankelecom, Ivo F J; Dehaen, Wim; Kazarian, Sergei G; Binnemans, Koen


    Novel difunctionalized ionic liquids (ILs) containing a triethylene glycol monomethyl ether chain and a nitrile group on a pyrrolidinium or imidazolium cation have been synthesized and incorporated into supported ionic liquid membranes (SILMs). These ILs exhibit ca. 2.3 times higher CO2/N2 and CO2/CH4 gas separation selectivities than analogous ILs functionalized only with a glycol chain. Although the glycol moiety ensures room temperature liquidity of the pyrrolidinium and imidazolium ILs, the two classes of ILs benefit from the presence of a nitrile group in different ways. The difunctionalized pyrrolidinium ILs exhibit an increase in CO2 permeance, whereas the permeances of the contaminant gases rise negligibly, resulting in high gas separation selectivities. In the imidazolium ILs, the presence of a nitrile group does not always increase the CO2 permeance nor does it increase the CO2 solubility, as showed in situ by the ATR-FTIR spectroscopic method. High selectivity of these ILs is caused by the considerably reduced permeances of N2 and CH4, most likely due to the ability of the -CN group to reject the nonpolar contaminant gases. Apart from the CO2 solubility, IL-CO2 interactions and IL swelling were studied with the in situ ATR-FTIR spectroscopy. Different strengths of the IL-CO2 interactions were found to be the major difference between the two classes of ILs. The difunctionalized ILs interacted stronger with CO2 than the glycol-functionalized ILs, as manifested in the smaller bandwidths of the bending mode band of CO2 for the latter. PMID:24895912

  17. Cycling and rate performance of Li–LiFePO 4 cells in mixed FSI–TFSI room temperature ionic liquids

    Microsoft Academic Search

    A. P. Lewandowski; A. F. Hollenkamp; S. W. Donne; A. S. Best


    A study is conducted of the performance of lithium iron(II) phosphate, LiFePO4, as a cathode material in a lithium secondary battery that features an ionic liquid electrolyte solution and a metallic lithium anode. The electrolyte solution comprises an ionic liquid of a N-methyl-N-alkyl-pyrrolidinium (alkyl=n-propyl or n-butyl) cation and either the bis(fluorosulfonyl)imide [(FSO2)2N?] or bis(trifluoromethanesulfonyl)imide [(F3CSO2)2N?] anion, together with 0.5molkg?1 of

  18. Lithium insertion in graphite from ternary ionic liquid-lithium salt electrolytes

    Microsoft Academic Search

    Giovanni B. Appetecchi; Maria Montanino; Andrea Balducci; Simon F. Lux; Martin Winterb; Stefano Passerini


    In this paper we report the results of chemical-physical investigation performed on ternary room temperature ionic liquid–lithium salt mixtures as electrolytes for lithium-ion battery systems. The ternary electrolytes were made by mixing N-methyl-N-propyl pyrrolidinium bis(fluorosulfonyl) imide (PYR13FSI) and N-butyl-N-methylpyrrolidinium bis(trifluoromethanesulfonyl) imide (PYR14TFSI) ionic liquids with lithium hexafluorophosphate (LiPF6) or lithium bis(trifluoromethanesulfonyl)imide (LiTFSI). The mixtures were developed based on preliminary results

  19. Lithium insertion in graphite from ternary ionic liquid–lithium salt electrolytes: II. Evaluation of specific capacity and cycling efficiency and stability at room temperature

    Microsoft Academic Search

    Simon F. Lux; Martin Schmuck; Giovanni B. Appetecchi; Stefano Passerini; Martin Winter; Andrea Balducci


    In this paper we report the results about the use of ternary room temperature ionic liquid–lithium salt mixtures as electrolytes for lithium-ion battery systems. Mixtures of N-methyl-N-propyl pyrrolidinium bis(fluorosulfonyl) imide, PYR13FSI, and N-butyl-N-methylpyrrolidinium bis(trifluoromethansulfonyl) imide, PYR14TFSI, with lithium hexafluorophosphate, LiPF6 and lithium bis(trifluoromethansulfonyl) imide, LiTFSI, containing 5wt.% of vinylene carbonate (VC) as additive, have been used in combination with a

  20. Method for measuring surface temperature


    Baker, Gary A. (Los Alamos, NM); Baker, Sheila N. (Los Alamos, NM); McCleskey, T. Mark (Los Alamos, NM)


    The present invention relates to a method for measuring a surface temperature using is a fluorescent temperature sensor or optical thermometer. The sensor includes a solution of 1,3-bis(1-pyrenyl)propane within a 1-butyl-1-1-methyl pyrrolidinium bis(trifluoromethylsulfonyl)imide ionic liquid solvent. The 1,3-bis(1-pyrenyl)propane remains unassociated when in the ground state while in solution. When subjected to UV light, an excited state is produced that exists in equilibrium with an excimer. The position of the equilibrium between the two excited states is temperature dependent.

  1. Studies on thermal properties of selected aprotic and protic ionic liquids

    SciTech Connect

    Luo, Huimin; Dai, Sheng; Huang, Jing-Fang


    We describe herein the thermal gravimetric analysis (TGA) and differential scanning calorimetry (DSC) investigations of the thermal properties of selected room-temperature ionic liquids (RTILs). The dependence of the thermal properties on both cation and anion structures of RTILs was systematically studied. The ionic liquids (ILs) investigated here include 28 different imidazolium-based ILs, 22 ammonium-based ILs, and 16 amide-based ILs. In general, these three cation classes exhibit different thermal behaviors but follow a quite systematic trend as expected from the corresponding structural variation. The ILs with bromide as the conjugate anion have lower thermal stabilities than those with bis(trifluoromethane sulfonyl) imide or bis(perfluoroethyl sulfonyl) imide as the conjugate anion. The mass of TGA samples and scan rate were found to have a systematic effect on the decomposition temperature of ILs, highlighting the caution needed in reporting TGA results.

  2. B?O?-added lithium aluminium germanium phosphate solid electrolyte for Li-O? rechargeable batteries.


    Jadhav, Harsharaj S; Kalubarme, Ramchandra S; Jang, Seong-Yong; Jung, Kyu-Nam; Shin, Kyoung-Hee; Park, Chan-Jin


    B2O3-added Li(1.5)Al(0.5)Ge(1.5)(PO4)3 (LAGP) glass ceramics showing a room temperature ionic conductivity of 0.67 mS cm(-1) have been synthesized by using a melt-quenching method. The prepared glass ceramics are observed to be stable in tetraethylene glycol dimethyl ether containing lithium bis(trifluoromethane) sulfonamide. The augmented conductivity of the B2O3-added LAGP glass ceramic has improved the plateau potential during discharge. Furthermore, the B2O3-added LAGP glass ceramics are successfully employed as a solid electrolyte in a Li-O2 battery to obtain a stable cycling lifetime of up to 15 cycles with the limited capacity protocol. PMID:24953185

  3. Development and Characterization of Poly(1-vinylpyrrolidone-co-vinyl acetate) Copolymer Based Polymer Electrolytes

    PubMed Central

    Sa'adun, Nurul Nadiah; Subramaniam, Ramesh; Kasi, Ramesh


    Gel polymer electrolytes (GPEs) are developed using poly(1-vinylpyrrolidone-co-vinyl acetate) [P(VP-co-VAc)] as the host polymer, lithium bis(trifluoromethane) sulfonimide [LiTFSI] as the lithium salt and ionic liquid, and 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl) imide [EMImTFSI] by using solution casting technique. The effect of ionic liquid on ionic conductivity is studied and the optimum ionic conductivity at room temperature is found to be 2.14?×?10?6?S?cm?1 for sample containing 25?wt% of EMImTFSI. The temperature dependence of ionic conductivity from 303?K to 353?K exhibits Arrhenius plot behaviour. The thermal stability of the polymer electrolyte system is studied by using thermogravimetric analysis (TGA) while the structural and morphological properties of the polymer electrolyte is studied by using Fourier transform infrared (FTIR) spectroscopy and X-ray diffraction analysis (XRD), respectively. PMID:25431781

  4. Studies on the effect of dispersoid(ZrO2) in PVdF-co-HFP based gel polymer electrolytes

    NASA Astrophysics Data System (ADS)

    Sivakumar, M.; Subadevi, R.; Muthupradeepa, R.


    Gel polymer electrolytes containing poly(vinylidenefluoride-co-hexafluoropropylene) (P(VdF-co-HFP)) / Lithium bis(trifluoromethane sulfon)imide (LiTFSI) / mixture of ethylene carbonate and propylene carbonate (EC+PC) with different concendration of ZrO2 has been prepared using the solution casting technique. The conductivity of the prepared electrolyte sample has been determined by AC impedance technique in the range 303-353K. The temperature dependent ionic conductivity plot seems to obey VTF relation. The maximum ionic conductivity value of 4.46 × 10-3S/cm has been obtained for PVdF-co-HFP(32%) - LiTFSI(8%) - EC+PC (60%) + ZrO2(6wt%) based polymer electrolyte. The surface morphology of the prepared electrolyte sample has been studied using SEM.

  5. Development and characterization of poly(1-vinylpyrrolidone-co-vinyl acetate) copolymer based polymer electrolytes.


    Sa'adun, Nurul Nadiah; Subramaniam, Ramesh; Kasi, Ramesh


    Gel polymer electrolytes (GPEs) are developed using poly(1-vinylpyrrolidone-co-vinyl acetate) [P(VP-co-VAc)] as the host polymer, lithium bis(trifluoromethane) sulfonimide [LiTFSI] as the lithium salt and ionic liquid, and 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl) imide [EMImTFSI] by using solution casting technique. The effect of ionic liquid on ionic conductivity is studied and the optimum ionic conductivity at room temperature is found to be 2.14 × 10(-6) S cm(-1) for sample containing 25 wt% of EMImTFSI. The temperature dependence of ionic conductivity from 303 K to 353 K exhibits Arrhenius plot behaviour. The thermal stability of the polymer electrolyte system is studied by using thermogravimetric analysis (TGA) while the structural and morphological properties of the polymer electrolyte is studied by using Fourier transform infrared (FTIR) spectroscopy and X-ray diffraction analysis (XRD), respectively. PMID:25431781

  6. Free Radical Polymerization of Styrene and Methyl Methacrylate in Various Room Temperature Ionic Liquids

    SciTech Connect

    Zhang, Hongwei; Hong, Kunlun; Mays, Jimmy


    Conventional free radical polymerization of styrene and methyl methacrylate was carried out in various room temperature ionic liquids (RTILs). The RTILs used in this research encompass a wide range of cations and anions. Typical cations include imidazolium, phosphonium, pyridinium, and pyrrolidinium; typical anions include amide, borate, chloride, imide, phosphate, and phosphinate. Reactions are faster and polymers obtained usually have higher molecular weights when compared to polymerizations carried out in volatile organic solvents under the same conditions. This shows that rapid rates of polymerization and high molecular weights are general features of conventional radical polymerizations in RTILs. Attempts to correlate the polarities and viscosities of the RTILs with the polymerization behavior fail to yield discernible trends.

  7. Estimation of toxicity of ionic liquids in Leukemia Rat Cell Line and Acetylcholinesterase enzyme by principal component analysis, neural networks and multiple lineal regressions.


    Torrecilla, José S; García, Julián; Rojo, Ester; Rodríguez, Francisco


    Multiple linear regression (MLR), radial basis network (RB), and multilayer perceptron (MLP) neural network (NN) models have been explored for the estimation of toxicity of ammonium, imidazolium, morpholinium, phosphonium, piperidinium, pyridinium, pyrrolidinium and quinolinium ionic liquid salts in the Leukemia Rat Cell Line (IPC-81) and Acetylcholinesterase (AChE) using only their empirical formulas (elemental composition) and molecular weights. The toxicity values were estimated by means of decadic logarithms of the half maximal effective concentration (EC(50)) in microM (log(10)EC(50)). The model's performances were analyzed by statistical parameters, analysis of residuals and central tendency and statistical dispersion tests. The MLP model estimates the log(10)EC(50) in IPC-81 and AchE with a mean prediction error less than 2.2 and 3.8%, respectively. PMID:18805639

  8. Impact of ionic liquids in environment and humans: an overview.


    Frade, Raquel Fm; Afonso, Carlos Am


    Ionic liquids enclose a large number of molecular structures consisting of a cation and an anion. Their physical state and their chemical properties can be tuned by different combination of the ions and a large number of ionic liquids have already been reported. Toxicity of ionic liquids is a subject of great importance concerning their likely use as greener solvents and new materials for a broad number of potential applications. This review provides relevant toxicological data published so far about this topic and includes a large range of ionic liquids based on different cations (imidazolium, pyridinium, pyrrolidinium, quaternary ammonium, quaternary phosphonium and guanidinium) and anions (halogens-Br, Cl, bis (trifluoromethyl)sulfonylamide, tetrafluoroborate, hexafluorophosphate, dicyanamide, acesulfame and saccharin, amongst others). In general, toxicity of ionic liquids depends on both ions and the effect of the cation alkyl chain length is very pronounced although the type of anion also exerts impact on the overall toxicity. PMID:20511289

  9. Composite Electrolytes for Lithium Batteries: Ionic Liquids in APTES Crosslinked Polymers

    NASA Technical Reports Server (NTRS)

    Tigelaar, Dean M.; Meador, Mary Ann B.; Bennett, William R.


    Solvent free polymer electrolytes were made consisting of Li(+) and pyrrolidinium salts of trifluoromethanesulfonimide added to a series of hyperbranched poly(ethylene oxide)s (PEO). The polymers were connected by triazine linkages and crosslinked by a sol-gel process to provide mechanical strength. The connecting PEO groups were varied to help understand the effects of polymer structure on electrolyte conductivity in the presence of ionic liquids. Polymers were also made that contain poly(dimethylsiloxane) groups, which provide increased flexibility without interacting with lithium ions. When large amounts of ionic liquid are added, there is little dependence of conductivity on the polymer structure. However, when smaller amounts of ionic liquid are added, the inherent conductivity of the polymer becomes a factor. These electrolytes are more conductive than those made with high molecular weight PEO imbibed with ionic liquids at ambient temperatures, due to the amorphous nature of the polymer.

  10. Role of Oxygen Mass Transport in Rechargeable Li/O2 Batteries Operating with Ionic Liquids.


    Monaco, Simone; Soavi, Francesca; Mastragostino, Marina


    The use of ionic liquid (IL)-based electrolytes and porous carbonaceous cathodes is today one of the most promising strategies for the development of rechargeable Li/O2 batteries. Enhancing Li/O2 battery cyclability at high discharge rate is a key issue for automotive applications. O2 reduction at a meso-macroporous carbon electrode in N-butyl-N-methyl pyrrolidinium bis(trifluoromethanesulfonyl)imide (PYR14TFSI):LiTFSI 9:1 is here investigated. The study demonstrates that oxygen electrode response in IL at high discharge currents is dominated by O2 mass transport in IL. A novel configuration of flow-Li/O2 battery that operates at high discharge rate is reported. PMID:26282288

  11. Mixtures of protic ionic liquids and propylene carbonate as advanced electrolytes for lithium-ion batteries.


    Vogl, T; Menne, S; Balducci, A


    In this study we investigated the chemical-physical properties of mixtures containing the protic ionic liquid (PIL) N-butyl-pyrrolidinium bis(trifluoromethanesulfonyl)imide (PYRH4TFSI), propylene carbonate (PC) and lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) in view of their use as electrolytes for lithium-ion batteries (LIBs). We showed that these electrolytic solutions might display conductivity and viscosity comparable to those of conventional electrolytes. Depending on the amount of PIL present inside the mixtures, such mixtures might also display the ability to suppress the anodic dissolution of Al. Furthermore, we showed that the coordination of lithium ions by TFSI in PIL-PC mixtures appears to be different than the one observed for mixtures of PC and aprotic ionic liquids (AILs). When used in combination with a battery electrode, e.g. lithium iron phosphate (LFP), these mixtures allow the achievement of high performance also at a very high C-rate. PMID:25328075

  12. Melting behavior and ionic conductivity in hydrophobic ionic liquids.


    Kunze, Miriam; Montanino, Maria; Appetecchi, Giovanni B; Jeong, Sangsik; Schönhoff, Monika; Winter, Martin; Passerini, Stefano


    Four room-temperature ionic liquids (RTILs) based on the N-butyl-N-methyl pyrrolidinium (Pyr(14)(+)) and N-methyl-N-propyl pyrrolidinium cations (Pyr(13)(+)) and bis(trifluoromethanesulfonyl)imide (TFSI(-)) and bis(fluorosulfonyl)imide (FSI(-)) anions were intensively investigated during their melting. The diffusion coefficients of (1)H and (19)F were determined using pulsed field gradient (PFG) NMR to study the dynamics of the cations, anions, and ion pairs. The AC conductivities were measured to detect only the motion of the charged particles. The melting points of these ionic liquids were measured by DSC and verified by the temperature-dependent full width at half-maximum (FWHM) of the (1)H and (19)F NMR peaks. The diffusion and conductivity data at low temperatures gave information about the dynamics at the melting point and allowed specifying the way of melting. In addition, the diffusion coefficients of (1)H (D(H)) and (19)F (D(F)) and conductivity were correlated using the Nernst-Einstein equation with respect to the existence of ion pairs. Our results show that in dependence on the cation different melting behaviors were identified. In the Pyr(14)-based ILs, ion pairs exist, which collapse above the melting point of the sample. This is in contrast to the Pyr(13)-based ILs where the present ion pairs in the crystal dissociate during the melting. Furthermore, the anions do not influence the melting behavior of the investigated Pyr(14) systems but affect the Pyr(13) ILs. This becomes apparent in species with a higher mobility during the breakup of the crystalline IL. PMID:20058901

  13. Polarizable force field development and molecular dynamics simulations of ionic liquids.


    Borodin, Oleg


    A many-body polarizable force field has been developed and validated for ionic liquids (ILs) containing 1-methyl-3-alkylimidazolium, 1-alkyl-2-methyl-3-alkylimidazolium, N-methyl-N-alkylpyrrolidinium, N-alkylpyridinium, N-alkyl-N-alkylpiperidinium, N-alkyl-N-alkylmorpholinium, tetraalkylammonium, tetraalkylphosphonium, N-methyl-N-oligoetherpyrrolidinium cations and BF(4)(-), CF(3)BF(3)(-), CH(3)BF(3)(-), CF(3)SO(3)(-), PF(6)(-), dicyanamide, tricyanomethanide, tetracyanoborate, bis(trifluoromethane sulfonyl)imide (Ntf(2)(-) or TFSI(-)), bis(fluorosulfonyl)imide (FSI(-)) and nitrate anions. Classical molecular dynamics (MD) simulations have been performed on 30 ionic liquids at 298, 333, and 393 K. The IL density, heat of vaporization, ion self-diffusion coefficient, conductivity, and viscosity were found in a good agreement with available experimental data. Ability of the developed force field to predict ionic crystal cell parameters has been tested on four ionic crystals containing Ntf(2)(-) anions. The influence of polarization on the structure and ion transport has been investigated for [emim][BF(4)] IL. A connection between the structural changes in IL resulting from turning off polarization and slowing down of ion dynamics has been found. Developed force field has also provided accurate description/prediction of thermodynamic and transport properties of alkanes, fluoroalkanes, oligoethers (1,2-dimethoxyethane), ethylene carbonate, propylene carbonate, dimethyl carbonate, hydrazine, methyhydrazine, dimethylhydrazine, acetonitrile, dimethyl amine, and dimethyl ketone. PMID:19637900

  14. Thermosensitive, soft glassy and structural colored colloidal array in ionic liquid: colloidal glass to gel transition.


    Ueno, Kazuhide; Inaba, Aya; Ueki, Takeshi; Kondoh, Masashi; Watanabe, Masayoshi


    A novel soft material comprising thermosensitive poly(benzyl methacrylate)-grafted silica nanoparticles (PBnMA-g-NPs) and the ionic liquid (IL), 1-ethyl-3-methylimidazolium bis(trifluoromethane sulfonyl)amide ([C(2)mim][NTf(2)]), was fabricated. The thermosensitive properties were studied over a wide range of particle concentrations and temperatures. PBnMA-g-NPs in the IL underwent the lower critical solution temperature (LCST) phase transition at lower temperatures with a broader transition temperature range as compared to the free PBnMA solution. Highly concentrated suspensions formed soft glassy colloidal arrays (SGCAs) exhibiting a soft-solid behavior and angle-independent structural color. For the first time, we report a discrete change in the angle-independent structural color of SGCAs with temperature because of a temperature-induced colloidal glass-to-gel transition. The interparticle interaction changed from repulsive to attractive at the LCST temperature, and it was characterized by a V-shaped rheological response and a direct electron microscope observation of the colloidal suspension in the IL. With unique rheological and optical properties as well as properties derived from the IL itself, the thermosensitive SGCAs may be of interest as a new material for a wide range of applications such as electrochemical devices and color displays. PMID:20979389

  15. Plasticized Polymer Composite Single-Ion Conductors for Lithium Batteries.


    Zhao, Hui; Asfour, Fadi; Fu, Yanbao; Jia, Zhe; Yuan, Wen; Bai, Ying; Ling, Min; Hu, Heyi; Baker, Gregory; Liu, Gao


    Lithium bis(trifluoromethane) sulfonamide (TFSI) is a promising electrolyte salt in lithium batteries, due to its good conductivity and high dissociation between the lithium cation and its anion. By tethering N-pentane trifluoromethane sulfonamide (C5NHTf), a TFSI analogue molecule, onto the surface of silica nanoparticle as a monolayer coverage should increase the Li(+) transference number to unity since anions bound to particles have reduced mobilities. Silica polymer composite has better mechanical property than that of the pure PEO. Analogously trifluoromethane sulfonic aminoethyl methacrylate (TfMA), a TFSI analogue vinyl monomer, was polymerized on silica nanoparticle surface as a multilayer coverage. Anchored polyelectrolytes to particle surfaces offer multiple sites for anions, and in principle the carrier concentration would increase arbitrarily and approach the carrier concentration of the bulk polyelectrolyte. Monolayer grafted nanoparticles have a lithium content of 1.2 × 10(-3) g Li/g, and multilayer grafted nanoparticles have a lithium content over an order higher at 2 × 10(-2) g Li/g. Electrolytes made from monolayer grafted particles exhibit a weak conductivity dependence on temperature, exhibiting an ionic conductivity in the range of 10(-6) S/cm when temperatures increase to 80 °C. While electrolytes made from multilayer grafted particles show a steep increase in conductivity with temperature with an ionic conductivity increase to 3 × 10(-5) S/cm at 80 °C, with an O/Li ratio of 32. PMID:26284984

  16. Preparation of ionic liquid based solid-phase microextraction fiber and its application to forensic determination of methamphetamine and amphetamine in human urine.


    He, Yi; Pohl, Jeremy; Engel, Robert; Rothman, Leah; Thomas, Marie


    A new solid-phase microextraction (SPME) procedure using an ionic liquid (IL) has been developed. Reusable IL-based SPME fiber was prepared for the first time by fixing IL through cross-linkage of IL impregnated silicone elastomer on the surface of a fused silica fiber. 1-Ethoxyethyl-3-methylimidazloium bis(trifluoromethane) sulfonylimide ([EeMim][NTf(2)]) ionic liquid was employed as a demonstration and the prepared fiber was applied to the forensic headspace determination of methamphetamine (MAP) and amphetamine (AP) in human urine samples. Important extraction parameters including the concentration of salt and base in sample matrix, extraction temperature and extraction time were investigated and optimized. Combined with gas chromatography/mass spectrometry (GC/MS) working in selected ion monitoring (SIM) mode, the new method showed good linearity in the range of 20-1500 microg L(-1), good repeatability (RSD<7.5% for MAP, and <11.5% for AP, n=6), and low detection limits (0.1 microg L(-1) for MAP and 0.5 microg L(-1) for AP). Feasibility of the method was evaluated by analyzing human urine samples. Although IL-based SPME is still at the beginning of its development stage, the results obtained by this work showed that it is a promising simple, fast and sensitive sample preparation method. PMID:19426983

  17. Spectroscopic and DFT studies to understand the liquid formation mechanism in the LiTFSI/acetamide complex system.


    Hu, Yongsheng; Wang, Zhaoxiang; Li, Hong; Huang, Xuejie; Chen, Liquan


    It is interesting that although both lithium bis(trifluoromethane sulfone) imide (LiN(SO2CF3)2, LiTFSI) and acetamide (CH3CONH2) are solid, their mixture is a liquid in an appropriate molar ratio range at room temperature. The liquid formation mechanism of the LiTFSI/acetamide complex has been investigated by FT-IR and FT-Raman spectroscopy. The spectroscopic studies show that the Li+ ions coordinate with the C=O group of acetamide whereas the SO2 group in TFSI- anions interacts with the NH2 group of acetamide via hydrogen bonding. These interactions lead to the breakage of the hydrogen bonds between acetamide molecules and to the dissociation of LiTFSI, resulting in the formation of this molten salt. Furthermore, it has been found that moderate interaction between LiX and RCONH2 (R = -NH2, -CH3 and -CF3) is favorable for forming a LiX/RCONH2 molten salt system with low eutectic temperature and high conductivity based on density functional theory (DFT) calculational and experimental comparison for different R groups in RCONH2 and different lithium salts. PMID:15911385

  18. In situ Raman spectroscopy of sulfur speciation in lithium-sulfur batteries.


    Wu, Heng-Liang; Huff, Laura A; Gewirth, Andrew A


    In situ Raman spectroscopy and cyclic voltammetry were used to investigate the mechanism of sulfur reduction in lithium-sulfur battery slurry cathodes with 1 M lithium bis(trifluoromethane sulfonyl)imide (LiTFSI) and tetraethylene glycol dimethyl ether (TEGDME)/1,3-dioxolane (DIOX) (1/1, v/v). Raman spectroscopy shows that long-chain polysulfides (S8(2-)) were formed via S8 ring opening in the first reduction process at ?2.4 V vs Li/Li(+) and short-chain polysulfides such as S4(2-), S4(-), S3(•-), and S2O4(2-) were observed with continued discharge at ?2.3 V vs Li/Li(+) in the second reduction process. Elemental sulfur can be reformed in the end of the charge process. Rate constants obtained for the appearance and disappearance polysulfide species shows that short-chain polysulfides are directly formed from S8 decomposition. The rate constants for S8 reappearance and polysulfide disappearance on charge were likewise similar. The formation of polysulfide mixtures at partial discharge was found to be quite stable. The CS2 additive was found to inhibit the sulfur reduction mechanism allowing the formation of long-chain polysulfides during discharge only and stabilizing the S8(2-) product. PMID:25543831

  19. Gas Permeation through Polystyrene-Poly(ethylene oxide) Block Copolymers

    NASA Astrophysics Data System (ADS)

    Hallinan, Daniel, Jr.; Minelli, Matteo; Giacinti-Baschetti, Marco; Balsara, Nitash


    Lithium air batteries are a potential technology for affordable energy storage. They consist of a lithium metal anode and a porous air cathode separated by a solid polymer electrolyte membrane, such as PEO/LiTFSI (PEO = poly(ethylene oxide), LiTFSI = lithium bis-trifluoromethane sulfonimide). For extended operation of such a battery, the polymer electrolyte must conduct lithium ions while blocking electrons and gases present in air. In order to maintain a pressure difference the membrane must be mechanically robust, which can be achieved by incorporating the PEO into a block copolymer with a glassy block such as PS (PS = polystyrene). To protect the lithium electrode, the membrane must have low permeability to gases in air such as CO2, N2, and O2. We have therefore studied the permeation of pure gases through a PS-PEO block copolymer. A high molecular weight, symmetric block copolymer with a lamellar morphology was used to cast free-standing membranes. Gas permeability was measured through these membranes with a standard, pressure-based technique. A model was developed to account for transport through the polymer membrane consisting of semi-crystalline PEO lamellae and amorphous PS lamellae. PEO crystallinity was extracted from the permeation model and compares well with values from differential scanning calorimetry measurements.

  20. Spectroscopic and DFT studies to understand the liquid formation mechanism in the LiTFSI/acetamide complex system

    NASA Astrophysics Data System (ADS)

    Hu, Yongsheng; Wang, Zhaoxiang; Li, Hong; Huang, Xuejie; Chen, Liquan


    It is interesting that although both lithium bis(trifluoromethane sulfone) imide (LiN(SO 2CF 3) 2, LiTFSI) and acetamide (CH 3CONH 2) are solid, their mixture is a liquid in an appropriate molar ratio range at room temperature. The liquid formation mechanism of the LiTFSI/acetamide complex has been investigated by FT-IR and FT-Raman spectroscopy. The spectroscopic studies show that the Li + ions coordinate with the C dbnd O group of acetamide whereas the SO 2 group in TFSI - anions interacts with the NH 2 group of acetamide via hydrogen bonding. These interactions lead to the breakage of the hydrogen bonds between acetamide molecules and to the dissociation of LiTFSI, resulting in the formation of this molten salt. Furthermore, it has been found that moderate interaction between LiX and RCONH 2 (R = sbnd NH 2, sbnd CH 3 and sbnd CF 3) is favorable for forming a LiX/RCONH 2 molten salt system with low eutectic temperature and high conductivity based on density functional theory (DFT) calculational and experimental comparison for different R groups in RCONH 2 and different lithium salts.

  1. Conductivity and Stability of Photopolymerized Polymer Electrolyte Network

    NASA Astrophysics Data System (ADS)

    Kyu, Thein; He, Ruixuan; Chen, Yu-Ming; Mao, Jialin; Zhu, Yu; Kyu'S Group, , Dr.; Zhu'S Group Collaboration, , Dr.


    A melt-processing window has been identified within the wide isotropic region of the phase diagram of ternary blends consisting of poly (ethylene glycol diacrylate) (PEGDA), tetraethylene glycol dimethyl ether (TEGDME) and lithium bis(trifluoromethane) sulfonamide (LiTFSI). Upon UV-crosslinking of PEGDA in the isotropic window, the polymer electrolyte membrane (PEM) network thus formed is completely transparent and remains in the single phase without undergoing polymerization-induced phase separation or polymerization-induced crystallization. These PEM networks are solid albeit flexible and light-weight with safety and space saving attributes. The ionic conductivity as determined by AC impedance spectroscopy exhibited very high room-temperature ionic conductivity on the order of ~10-3 S/cm in several compositions, viz., 10/45/45, 20/40/40 and 30/35/35 PEGDA/TEGDME/LiTFSI networks. Cyclic voltammetry measurement of these solid-state PEM networks revealed excellent electrochemical stability against lithium reference electrode. The above study has been extended to the anode (graphite) and cathode (LiFePO4) half-cell configurations with lithium as counter electrode. Charge/discharge cycling behavior of these half cells will be discussed. Supported by NSF-DMR 1161070 and University of Akron.

  2. Transport Properties of LiTFSI-Acetamide Room Temperature Molten Salt Electrolytes Applied in an Li-Ion Battery

    NASA Astrophysics Data System (ADS)

    Yang, Chao-Chen; Hsu, Hsin-Yi; Hsu, Chen-Ruei


    In the present work some transport properties of the binary room temperature molten salt (RTMS) lithium bis(trifluoromethane sulfone)imide (LiTFSI)-acetamide [LiN(SO2CF3)2-CH3CONH2], applied in an Li-ion battery, have been investigated. The phase diagram was determined by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The result reveals that the binary RTMS has an eutectic point at 201 K and the 30 mol% LiTFSI composition. The electric conductivity was measured using a direct current computerized method. The result shows that the conductivities of the melts increase with increasing temperature and acetamide content. The densities of all melts decrease with increasing temperature and acetamide content. The equivalent conductivities were fitted by the Arrhenius equation, where the activation energies were 18.15, 18.52, 20.35, 25.08 kJ/mol for 10, 20, 30, 40 mol% LiTFSI, respectively. Besides the relationships between conductivity, density composition and temperature, of the ion interaction is discussed.

  3. Temperature effects on the electrochemical behavior of spinel LiMn(2)O(4) in quaternary ammonium-based ionic liquid electrolyte.


    Zheng, Honghe; Zhang, Hucheng; Fu, Yanbao; Abe, Takeshi; Ogumi, Zempachi


    Temperature dependence of the physiochemical characteristics of a room-temperature ionic liquid consisting of trimethylhexylammonium (TMHA) cation and bis(trifluoromethane) sulfonylimide (TFSI) anion containing different concentrations of LiTFSI salt was examined. Electrochemical properties of a spinel LiMn(2)O(4) electrode in 1 M LiTFSI/TMHA-TFSI ionic electrolyte were investigated at different temperatures by using cyclic voltammetry, galvanostatic measurements, and electrochemical impedance spectroscopy. The Li/ionic electrolyte/LiMn(2)O(4) cell exhibited satisfactory electrochemical properties with a discharge capacity of 108.2 mA h/g and 91.4% coulombic efficiency in the first cycle under room temperature. At decreased temperature, reversible capacity of the cell could not attain a satisfactory value due to the high internal resistance of the cell and the large activation energy for lithium ion transfer through the electrode/electrolyte interface. Anodic electrolyte oxidation results in the decrease of coulombic efficiency with increasing temperature. Irreversible structural conversion of the spinel LiMn(2)O(4) in the ionic electrolyte, possibly associated with the formation of TMHA intercalated compounds and/or Jahn-Teller distortion, was considered to be responsible for the electrochemical decay with increasing cycles. PMID:16852714

  4. Role of Succinonitrile in a Poly(ethylene oxide)/LiTFSI membrane for lithium batteries

    NASA Astrophysics Data System (ADS)

    Echeverri, Mauricio; Kyu, Thein


    In designing novel flexible lithium battery membranes, high conductivity, peel strength and processability are the main targets for a successful product. Crystallinity of poly(ethylene oxide) (PEO) and lithium salts represent an obstacle to accomplish each of these specifications. We present a systematic study of ternary phase diagrams of PEO, bis(trifluoromethane) sulfonimide (LiTFSI) and succinonitrile (SCN) (i.e., solid plasticizer/co-solvent) mixtures by using DSC and polarized optical microscopy and map out various coexistence regions bound by the liquidus and solidus lines. The eutectic phase diagram of PEO/SCN system was calculated self-consistently using Flory-Huggins theory in conjunction with Landau-type phase field free energy for crystal solidification. Specific interactions such as hydrogen bonding were examined by FTIR. In lieu of PEO, poly(ethylene glycol) diacrylate (PEGDA) were used to completely eliminate all crystals. Further, photopolymerization of PEGDA affords a solid network containing LiTFSI and SCN that shows promising improvements with a conductivity value of 10-4 S/cm at 25°C.

  5. Effects of TiO2 addition on ionic conductivity of PVC/PEMA blend based composite polymer electrolyte

    NASA Astrophysics Data System (ADS)

    Subban, R. H. Y.; Sukri, Nursyazwani


    PVC/PEMA blend based polymer electrolytes with lithium bistrifluoromethane sulfonimide (LiN(CF3SO2)2) and PVC/PEMA/(LiN(CF3SO2)2-TiO2 films were prepared by solution cast technique. The sample containing 35 wt. % LiN(CF3SO2)2 exhibited the highest conductivity of 1.75 × 10-5 Scm-1. The conductivity of the sample increased to 2.12 × 10-5 Scm-1 and 4.61 × 10-5 Scm-1 when 4 wt. % and 10 wt. % of titanium dioxide (TiO2) was added to the sample at 65 wt. % PVC/PEMA-35 wt. % LiN(CF3SO2)2 composition respectively. The low increase in conductivity is attributed to two competing factors: increase in crystallinity as accounted by X-Ray diffraction (XRD) and decrease in glass transition temperature as accounted by differential scanning calorimetry (DSC).

  6. Ion conduction in phosphonium-polysiloxane ionomers

    NASA Astrophysics Data System (ADS)

    Liang, Siwei; Hyeok Choi, U.; Runt, James; Colby, Ralph


    Low Tg ionomers with phosphonium cations covalently attached as side chains have potential application in energy conversion and storage devices. For example, alkaline fuel cells rely on membranes that transport hydroxide anions and some advanced batteries rely on membranes transporting fluoride anions. To better understand ion conduction in phosphonium-polysiloxane ionomers, allyl tributyl phosphonium bromide monomer was synthesized and, along with a vinyl ethylene oxide monomer, attached to polymethylhydrosiloxane by hydrosilylation. These ionomers maintain low Tg -74 ^oC with up to 10 mol% phosphonium and are fully water soluble, allowing easy anion exchange and purification. We report dielectric spectroscopy results for these ionomers with a variety of counter-anions. Electrode polarization at low frequencies is analyzed to determine the number density of simultaneously conducting counter ions and their mobility. This analysis reveals higher mobility and lower activation energy for conducting anions that are larger and more diffuse, such as bis(trifluoromethane sulfonyl)imide, contributing to better performance as anion-conducting membranes.

  7. Control of the recombination rate by changing the polarity of the electrolyte in dye-sensitized solar cells.


    Idigoras, Jesús; Tena-Zaera, Ramón; Anta, Juan A


    Recombination in Dye-sensitized Solar Cells (DSCs) is an electron transfer process critical for high efficiency. The chemical nature of the electron acceptor is known to have an important impact on recombination and, hence, limits the choice of hole conductors in DSCs and related solar cells. In this respect, Room Temperature Ionic liquids (RTILs) have been recognized as an alternative to volatile organic solvents due to their negligible vapor pressure, which offers the chance for long-term stability. However, RTIL-based electrolytes lead to lower performance, a feature that has been attributed to the high viscosity of ionic liquids and the mass-transport limitation associated with it. In this work we show that the origin of the lower performance is also related to an increase in the recombination loss due to the polar nature of the RTIL and the influence of the reorganization energy of the electron acceptor in a polar environment. To investigate this chemical effect, different mixing ratios of RTILs and an organic solvent (acetonitrile) have been considered. The fabricated devices have been characterized by small-perturbation techniques (Impedance Electrochemical Spectroscopy and Intensity-Modulated Photovoltage and Photocurrent Spectroscopies) and Open-Circuit Voltage Decay measurements, which have been used to extract electron lifetimes at different applied voltages. Two different ruthenium dyes (hydrophilic N719 and hydrophobic Z907) and two different cations in the RTIL (imidazolium- and pyrrolidinium-based) have been considered. The results obtained show that for pure ionic liquids the lifetime-voltage curve is exponential, which is a signature of large reorganization energies for electron transfer. In contrast, pure acetonitrile exhibits a non-exponential behavior, which is consistent with relatively low reorganization energy. Interestingly, and as a general rule, we find that recombination is faster in systems with higher reorganization energies. This is interpreted as a consequence of the availability of more acceptor states for electron transfer. In addition, it is found that mixing RTILs and acetonitrile is an interesting strategy to increase the stability of DSCs without significant recombination losses, provided that the right dye and RTIL, in particular, a pyrrolidinium component, are used. PMID:25184736

  8. Evaporation of ionic liquids at atmospheric pressure: study by ion mobility spectrometry.


    Holopainen, S; Nousiainen, M; Puton, J; Sillanpää, M; Bardi, U; Tolstogouzov, A


    A conventional ion mobility spectrometry (IMS) was used to study atmospheric pressure evaporation of seven pure imidazolium and pyrrolidinium ionic liquids (ILs) with [Tf(2)N], [PF(6)], [BF(4)] and [fap] anions. The positive drift time spectra of the as-received samples measured at 220°C exhibited close similarity; the peak at reduced mobility K(0)=1.99 cm(2)V(-1)s(-1) was a dominant spectral pattern of imidazolium-based ILs. With an assumption that ILs vapor consists mainly of neutral ion pairs, which generate the parent cations in the reactant section of the detector, and using the reference data on the electrical mobility of ILs cations and clusters, this peak was attributed to the parent cation [emim]. Despite visible change in color of the majority of ILs after the heating at 220°C for 5h, essential distinctions between spectra of the as-received and heated samples were not observed. In negative mode, pronounced peaks were registered only for ILs with [fap] anion. PMID:21147336

  9. Photodetachment, electron cooling, and recombination, in a series of neat aliphatic room temperature ionic liquids

    NASA Astrophysics Data System (ADS)

    Molins i Domenech, Francesc; Healy, Andrew T.; Blank, David A.


    Transient absorption following photodetachment of a series of neat methyl-alkyl-pyrrolidinium bis(trifluoromethylsulfonyl)amides at 6.20 eV was measured with sub-picosecond time resolution in the visible and near-IR portions of the spectrum. This series spans the onset of structuring in the liquids in the form of polarity alternation. Excitation promotes the electron into a delocalized state with a very large reactive radius. Strong transient absorption is observed in the visible spectrum with a ˜700 fs lifetime, and much weaker, long-lived absorption is observed in the near-IR spectrum. Absorption in the visible is shown to be consistent with the hole, and absorption in the near-IR is assigned to the free solvated electron. Yield of free electrons is estimated at ˜4%, is insensitive to the size of the cation, and is determined in less than 1 ps. Solvation of free electrons depends strongly on the size of the cation and correlates well with the viscosity of the liquid. In addition to radiolytic stability of the aliphatic cations, ultrafast, efficient recombination of separated charge in NTf2 - based ionic liquids following photo-excitation near the band-gap may prevent subsequent reactive damage associated with anions.

  10. Photodetachment, electron cooling, and recombination, in a series of neat aliphatic room temperature ionic liquids.


    Molins I Domenech, Francesc; Healy, Andrew T; Blank, David A


    Transient absorption following photodetachment of a series of neat methyl-alkyl-pyrrolidinium bis(trifluoromethylsulfonyl)amides at 6.20 eV was measured with sub-picosecond time resolution in the visible and near-IR portions of the spectrum. This series spans the onset of structuring in the liquids in the form of polarity alternation. Excitation promotes the electron into a delocalized state with a very large reactive radius. Strong transient absorption is observed in the visible spectrum with a ?700 fs lifetime, and much weaker, long-lived absorption is observed in the near-IR spectrum. Absorption in the visible is shown to be consistent with the hole, and absorption in the near-IR is assigned to the free solvated electron. Yield of free electrons is estimated at ?4%, is insensitive to the size of the cation, and is determined in less than 1 ps. Solvation of free electrons depends strongly on the size of the cation and correlates well with the viscosity of the liquid. In addition to radiolytic stability of the aliphatic cations, ultrafast, efficient recombination of separated charge in NTf2 (-) based ionic liquids following photo-excitation near the band-gap may prevent subsequent reactive damage associated with anions. PMID:26277144

  11. Effect of cation type, alkyl chain length, adsorbate size on adsorption kinetics and isotherms of bromide ionic liquids from aqueous solutions onto microporous fabric and granulated activated carbons.


    Hassan, Safia; Duclaux, Laurent; Lévêque, Jean-Marc; Reinert, Laurence; Farooq, Amjad; Yasin, Tariq


    The adsorption from aqueous solution of imidazolium, pyrrolidinium and pyridinium based bromide ionic liquids (ILs) having different alkyl chain lengths was investigated on two types of microporous activated carbons: a fabric and a granulated one, well characterized in terms of surface chemistry by "Boehm" titrations and pH of point of zero charge measurements and of porosity by N2 adsorption at 77 K and CO2 adsorption at 273 K. The influence of cation type, alkyl chain length and adsorbate size on the adsorption properties was analyzed by studying kinetics and isotherms of eight different ILs using conductivity measurements. Equilibrium studies were carried out at different temperatures in the range [25-55 °C]. The incorporation of ILs on the AC porosity was studied by N2 adsorption-desorption measurements at 77 K. The experimental adsorption isotherms data showed a good correlation with the Langmuir model. Thermodynamic studies indicated that the adsorption of ILs onto activated carbons was an exothermic process, and that the removal efficiency increased with increase in alkyl chain length, due to the increase in hydrophobicity of long chain ILs cations determined with the evolution of the calculated octanol-water constant (Kow). The negative values of free energies indicated that adsorption of ILs with long chain lengths having hydrophobic cations was more spontaneous at the investigated temperatures. PMID:24929502

  12. Extraction Separation of Rare-Earth Ions via Competitive Ligand Complexations between Aqueous and Ionic-Liquid Phases

    SciTech Connect

    Luo, Huimin; Sun, Xiaoqi; Bell, Jason R; Dai, Sheng


    The extraction separation of rare earth elements is the most challenging separation processes in hydrometallurgy and advanced nuclear fuel cycles. The TALSPEAK process (Trivalent Actinide Lanthanide Separations by Phosphorus-reagent Extraction from Aqueous Komplexes) is a prime example of these separation processes. The objective of this paper is to explore the use of ionic liquids (ILs) for the TALSPEAK-like process, to further enhance its extraction efficiencies for lanthanides, and to investigate the potential of using this modified TALSPEAK process for separation of lanthanides among themselves. Eight imidazolium ILs ([Cnmim][NTf2] and [Cnmim][BETI], n=4,6,8,10) and one pyrrolidinium IL ([C4mPy][NTf2]) were investigated as diluents using di(2-ethylhexyl)phosphoric acid (HDEHP) as an extractant for separation of lanthanide ions from aqueous solutions of 50 mM glycolic acid or citric acid and 5 mM diethylenetriamine pentaacetic acid (DTPA). The extraction efficiencies were studied in comparison with diisopropylbenzene (DIPB), an organic solvent used as diluent for the conventional TALSPEAK extraction system. Excellent extraction efficiencies and selectivities were found for a number of lanthanide ions using HDEHP as an extractant in these ILs. The effects of different alkyl chain lengths in the cations of ILs and anions on extraction efficiencies and selectivities of lanthanide ions are also presented in this paper.

  13. Structural and electrochemical properties of succinonitrile-based gel polymer electrolytes: role of ionic liquid addition.


    Suleman, Mohd; Kumar, Yogesh; Hashmi, S A


    Experimental studies on the novel compositions of gel polymer electrolytes, comprised of plastic crystal succinonitrile (SN) dispersed with pyrrolidinium and imidazolium-based ionic liquids (ILs) entrapped in a host polymer poly(vinylidine fluoride-co-hexafluoropropylene) (PVdF-HFP), are reported. The gel electrolytes are in the form of free-standing films with excellent mechanical, thermal, and electrochemical stability. The introduction of even a small content (~1 wt %) of ionic liquid (1-butyl-1-methylpyrrolidinium bis(trifluoromethyl-sulfonyl)imide (BMPTFSI) or 1-ethyl-3-methylimidazolium trifluoromethanesulfonate (EMITf) in the PVdF-HFP/SN system (1:4 w/w) enhances the electrical conductivity by 4 orders of magnitude, that is, from ~10(-7) to ~10(-3) S cm(-1) at room temperature. The structural changes due to the entrapment of SN or SN/ILs mixtures and ion-SN-polymer interactions are examined by Fourier transform infrared (FTIR)/Raman spectroscopy, scanning electron microscopy (SEM), X-ray diffraction (XRD), and differential scanning calorimmetry (DSC). Various physicochemical properties and fast ion conduction in the gel polymer membranes show their promising characteristics as electrolytes in different ionic devices including supercapacitors. PMID:23758408

  14. Characterization of the bridged proton structure in HTFSI acid ionic liquid solutions.


    Munson, Kyle T; Vergara, Jason; Yu, Lei; Vaden, Timothy D


    Acidic ionic liquid (AIL) solutions were prepared by dissolving bis(trifluoromethanesulfonyl)imide (HTFSI) acid in the ionic liquid (IL) 1-butyl-3-methylpyrrolidinium bis(trifloromethanesulfonyl)imide (PyrrTFSI). The HTFSI/PyrrTFSI solutions were investigated by conductivity measurements, optical spectroscopy, and DFT calculations in order to understand the ionization/solvation mechanism of HTFSI in the solutions. The HTFSI/PyrrTFSI solution conductivities first increased at lower concentrations and then decreased when the concentration of HTFSI is higher than ?1.5 M. The spectroscopic results indicate that the solvation structure may evolve from lower to higher concentrations to make protonated TFSI(-) motifs. Both spectroscopic and DFT simulation results support the observation of proton-sharing [H(TFSI)2](-) dimers, which may form through a bridged hydrogen in the format of either a N-H-N connection or a N-H-O connection. Both configurations may exist in the AIL solution. The proton-sharing mechanism implied by these structures confirms that the TFSI(-) ion can be a proton acceptor and a Brønsted base as well in IL solutions. However, the IL molecular cations such as imidazolium and (in this work) pyrrolidinium do not contribute significantly to the proton solvation and transportation in the solutions. PMID:25932889

  15. Ionic liquids for rechargeable lithium batteries

    SciTech Connect

    Salminen, Justin; Papaiconomou, Nicolas; Kerr, John; Prausnitz,John; Newman, John


    We have investigated possible anticipated advantages of ionic-liquid electrolytes for use in lithium-ion batteries. Thermal stabilities and phase behavior were studied by thermal gravimetric analysis and differential scanning calorimetry. The ionic liquids studied include various imidazoliumTFSI systems, pyrrolidiniumTFSI, BMIMPF{sub 6}, BMIMBF{sub 4}, and BMIMTf. Thermal stabilities were measured for neat ionic liquids and for BMIMBF{sub 4}-LiBF{sub 4}, BMIMTf-LiTf, BMIMTFSI-LiTFSI mixtures. Conductivities have been measured for various ionic-liquid lithium-salt systems. We show the development of interfacial impedance in a Li|BMIMBF{sub 4} + LiBF{sub 4}|Li cell and we report results from cycling experiments for a Li|BMIMBF{sub 4} + 1 mol/kg LIBF{sub 4}|C cell. The interfacial resistance increases with time and the ionic liquid reacts with the lithium electrode. As expected, imidazolium-based ionic liquids react with lithium electrodes. We seek new ionic liquids that have better chemical stabilities.

  16. Ionic liquids effects on the permeability of photosynthetic membranes probed by the electrochromic shift of endogenous carotenoids.


    Malferrari, Marco; Malferrari, Danilo; Francia, Francesco; Galletti, Paola; Tagliavini, Emilio; Venturoli, Giovanni


    Ionic liquids (ILs) are promising materials exploited as solvents and media in many innovative applications, some already used at the industrial scale. The chemical structure and physicochemical properties of ILs can differ significantly according to the specific applications for which they have been synthesized. As a consequence, their interaction with biological entities and toxicity can vary substantially. To select highly effective and minimally harmful ILs, these properties need to be investigated. Here we use the so called chromatophores - protein-phospholipid membrane vesicles obtained from the photosynthetic bacterium Rhodobacter sphaeroides- to assess the effects of imidazolinium and pyrrolidinium ILs, with chloride or dicyanamide as counter anions, on the ionic permeability of a native biological membrane. The extent and modalities by which these ILs affect the ionic conductivity can be studied in chromatophores by analyzing the electrochromic response of endogenous carotenoids, acting as an intramembrane voltmeter at the molecular level. We show that chromatophores represent an in vitro experimental model suitable to probe permeability changes induced in cell membranes by ILs differing in chemical nature, degree of oxygenation of the cationic moiety and counter anion. PMID:26343161

  17. Functionalized Fullerenes in Photodynamic Therapy

    PubMed Central

    Huang, Ying-Ying; Sharma, Sulbha K.; Yin, Rui; Agrawal, Tanupriya; Chiang, Long Y.; Hamblin, Michael R.


    Since the discovery of C60 fullerene in 1985, scientists have been searching for biomedical applications of this most fascinating of molecules. The unique photophysical and photochemical properties of C60 suggested that the molecule would function well as a photosensitizer in photodynamic therapy (PDT). PDT uses the combination of non-toxic dyes and harmless visible light to produce reactive oxygen species that kill unwanted cells. However the extreme insolubility and hydrophobicity of pristine C60, mandated that the cage be functionalized with chemical groups that provided water solubility and biological targeting ability. It has been found that cationic quaternary ammonium groups provide both these features, and this review covers work on the use of cationic fullerenes to mediate destruction of cancer cells and pathogenic microorganisms in vitro and describes the treatment of tumors and microbial infections in mouse models. The design, synthesis, and use of simple pyrrolidinium salts, more complex decacationic chains, and light-harvesting antennae that can be attached to C60, C70 and C84 cages are covered. In the case of bacterial wound infections mice can be saved from certain death by fullerene-mediated PDT. PMID:25544837

  18. Exploring electrochemical windows of room-temperature ionic liquids: a computational study.


    Tian, Yong-Hui; Goff, George S; Runde, Wolfgang H; Batista, Enrique R


    Room-temperature ionic liquids (RTILs) are regarded as green solvents due to their low volatility, low flammability, and thermal stability. RTILs exhibit wide electrochemical windows, making them prime candidates as media for electrochemically driven reactions such as electro-catalysis and electro-plating for separations applications. Therefore, understanding the factors determining edges of the electrochemical window, the electrochemical stability of the RTILs, and the degradation products is crucial to improve the efficiency and applicability of these systems. We present here computational investigations of the electrochemical properties of a variety of RTILs covering a wide range of electrochemical windows. We proposed four different approaches with different degrees of approximation and computational cost from gas-phase calculations to full explicit solvation models. It was found that, whereas the simplest model has significant flaws in accuracy, implicit and explicit solvent models can be used to reliably predict experimental data. The general trend of electrochemical windows of the RTILs studied is well reproduced, showing that it increases in the order of imidazolium < ammonium < pyrrolidinium < phosphonium giving confidence to the methodology presented to use it in screening studies of ionic liquids. PMID:22946441

  19. Soft glassy colloidal arrays in an ionic liquid: colloidal glass transition, ionic transport, and structural color in relation to microstructure.


    Ueno, Kazuhide; Sano, Yuta; Inaba, Aya; Kondoh, Masashi; Watanabe, Masayoshi


    The colloidal glass transition, ionic transport, and optical properties of soft glassy colloidal arrays (SGCAs) that consist of poly(methyl methacrylate) (PMMA)-grafted silica nanoparticles (PMMA-g-NPs) and a room-temperature ionic liquid, 1-ethyl-3-methylimidazolium bis(trifluoromethane sulfonyl)amide ([C(2)mim][NTf(2)]), were investigated. At lower particle concentrations, PMMA-g-NPs were well-suspended in the IL without any aggregation or sedimentation, and the dilute suspensions showed liquid-like behavior. However, above a certain particle concentration, the suspensions became solidified and exhibited different structural colors depending on the particle concentrations. The liquid-solid transition of the SGCAs was essentially caused by colloidal glass transition. Due to the soft repulsive interaction between the particles, the effective volume fraction of the particle (?(eff)) required for colloidal glass transition was higher than that of the hard sphere system and found to be approximately 0.70-0.74. The SGCA had sufficient ionic conductivity, which was greater than 10(-3) S cm(-1) at room temperature, even in the highly concentrated region. For ionic transport of the cation and the anion in the SGCAs, the decrease in diffusivity observed with the addition of the particles (D(g)/D(0)) was slightly greater for the [NTf(2)] anion than that of the [C(2)mim] cation, suggesting that the [NTf(2)] anion preferentially interacts with the PMMA chains. The SGCAs showed homogeneous, nonbrilliant, and angle-independent structural colors above the glass transition volume fraction. In addition, the color of the SGCAs changed from red to green to blue as the particle concentration increased. A linear relationship was found between the maximum wavelength of the reflection spectra and the center-to-center distance in the SGCAs. PMID:20879726

  20. Physicochemical properties and structures of room temperature ionic liquids. 2. Variation of alkyl chain length in imidazolium cation.


    Tokuda, Hiroyuki; Hayamizu, Kikuko; Ishii, Kunikazu; Susan, Md Abu Bin Hasan; Watanabe, Masayoshi


    The alkyl chain length of 1-alkyl-3-methylimidazolium bis(trifluoromethane sulfonyl)imide ([Rmim][(CF(3)SO(2))(2)N], R = methyl (m), ethyl (e), butyl (b), hexyl (C(6)), and octyl (C(8))) was varied to prepare a series of room-temperature ionic liquids (RTILs), and the thermal behavior, density, viscosity, self-diffusion coefficients of the cation and anion, and ionic conductivity were measured over a wide temperature range. The self-diffusion coefficient, viscosity, ionic conductivity, and molar conductivity change with temperature following the Vogel-Fulcher-Tamman equation, and the density shows a linear decrease. The pulsed-field-gradient spin-echo NMR method reveals a higher self-diffusion coefficient for the cation compared to that for the anion over a wide temperature range, even if the cationic radius is larger than that of the anion. The summation of the cationic and anionic diffusion coefficients for the RTILs follows the order [emim][(CF(3)SO(2))(2)N] > [mmim][(CF(3)SO(2))(2)N] > [bmim][(CF(3)SO(2))(2)N] > [C(6)mim][(CF(3)SO(2))(2)N] > [C(8)mim][(CF(3)SO(2))(2)N], which greatly contrasts to the viscosity data. The ratio of molar conductivity obtained from impedance measurements to that calculated by the ionic diffusivity using the Nernst-Einstein equation quantifies the active ions contributing to ionic conduction in the diffusion components, in other words, ionicity of the ionic liquids. The ratio decreases with increasing number of carbon atoms in the alkyl chain. Finally, a balance between the electrostatic and induction forces has been discussed in terms of the main contribution factor in determining the physicochemical properties. PMID:16851672

  1. Aggregation behaviors of dodecyl sulfate-based anionic surface active ionic liquids in water.


    Jiao, Jingjing; Dong, Bin; Zhang, Huina; Zhao, Yingyuan; Wang, Xiaoqing; Wang, Rui; Yu, Li


    Halogen-free, low-cost alkyl sulfate-based surface active ionic liquids (SAILs), 1-butyl-3-methylimidazolium dodecyl sulfate ([C(4)mim][C(12)SO(4)]), and N-butyl-N-methylpyrrolidinium dodecyl sulfate ([C(4)MP][C(12)SO(4)]) were easily synthesized through ion exchange reaction. The aggregation behaviors of [C(4)mim][C(12)SO(4)] and [C(4)MP][C(12)SO(4)] in aqueous solution were investigated by surface tension, electric conductivity, and static fluorescence quenching. Both [C(4)mim][C(12)SO(4)] and [C(4)MP][C(12)SO(4)] have rather lower cmc, ?(cmc) values and higher pC(20), ?(cmc) values than those reported for the traditional ionic surfactant, sodium dodecyl sulfate (SDS), and imidazolium-based SAIL, 1-dodecyl-3-methylimidazolium bromide ([C(12)mim]Br), with the same hydrocarbon chain length. The thermodynamic parameters evaluated from electric conductivity measurements show that the micelle formation of [C(4)mim][C(12)SO(4)] and [C(4)MP][C(12)SO(4)] is entropy-driven in the temperature range investigated. Lower average aggregation number indicates that the micelles of two SAILs present much looser structure. It is found that both the nature and the ring type of counterions can affect the aggregation behavior in aqueous solution. (1)H NMR results of [C(4)mim][C(12)SO(4)] were used to further verify the mechanism of micelle formation. Hydration ability and steric hindrance of the imidazolium or pyrrolidinium counterion as well as the cooperative hydrophobic interaction of longer alkyl chain of [C(12)SO(4)] anion and comparatively shorter alkyl chain of [C(4)mim] or [C(4)MP] cation are proposed to play critical roles in the aggregation of [C(4)mim][C(12)SO(4)] and [C(4)MP][C(12)SO(4)]. PMID:22204280

  2. Interaction of bovine serum albumin with ester-functionalized anionic surface-active ionic liquids in aqueous solution: a detailed physicochemical and conformational study.


    Wang, Xiaoqing; Liu, Jie; Sun, Limei; Yu, Li; Jiao, Jingjing; Wang, Rui


    Ester-functionalized anionic surface-active ionic liquids (SAILs), 3-methyl-1-(ethoxycarbonylmethyl)imidazolium dodecylsulfate ([C(1)COOC(2)C(1)im][C(12)SO(4)]) and 3-methyl-1-(ethoxycarbonylmethyl)pyrrolidinium dodecylsulfate ([C(1)COOC(2)C(1)Py][C(12)SO(4)]), were synthesized. The tensiometric profiles demonstrate that, in pure water, the studied SAILs exhibit higher surface activity than the traditional anionic surfactant, sodium dodecyl sulfate (SDS), and cationic SAILs, 1-dodecyl-3-methylimidazolium bromide ([C(12)mim]Br) and N-dodecyl-N-methylpyrrolidimium bromide (C(12)MPB), with the same hydrocarbon chain length. The interaction between bovine serum albumin (BSA) and the anionic SAILs in pH 7.4 buffer solution was systematically investigated by various techniques. The results show that the cationic ring has a slight effect on the BSA-SAIL interaction. The binding isotherms of BSA with the SAILs display four characteristic regions with increasing SAIL concentration. The unfolding of BSA occurs in the third region. Fluorescence spectroscopy indicates that the studied SAILs cause the exposure of tryptophan residues to a hydrophobic environment, and [C(1)COOC(2)C(1)im][C(12)SO(4)] can more effectively reduce the fluorescence intensity of BSA at low SAIL concentrations than [C(1)COOC(2)C(1)Py][C(12)SO(4)]. Circular dichroism spectroscopy evidences that the denaturation extent of BSA induced by [C(1)COOC(2)C(1)im][C(12)SO(4)] is higher than that of [C(1)COOC(2)C(1)Py][C(12)SO(4)]. PMID:22992068

  3. The effect of the cation alkyl chain branching on mutual solubilities with water and toxicities

    PubMed Central

    Kurnia, Kiki A.; Sintra, Tânia E.; Neves, Catarina M. S. S.; Shimizu, Karina; Lopes, José N. Canongia; Gonçalves, Fernando; Ventura, Sónia P. M.; Freire, Mara G.; Santos, Luís M. N. B. F.; Coutinho, João A. P.


    The design of ionic liquids has been focused on the cation-anion combinations but other more subtle approaches can be used. In this work the effect of the branching of the cation alkyl chain on the design of ionic liquids (ILs) is evaluated. The mutual solubilities with water and toxicities of a series of bis(trifluoromethylsulfonyl)-based ILs, combined with imidazolium, pyridinium, pyrrolidinium, and piperidinium cations with linear or branched alkyl chains, are reported. The mutual solubility measurements were carried out in the temperature range from (288.15 to 323.15) K. From the obtained experimental data, the thermodynamic properties of the solution (in the water-rich phase) were determined and discussed. The COnductor like Screening MOdel for Real Solvents (COSMO-RS) was used to predict the liquid-liquid equilibrium. Furthermore, molecular dynamic simulations were also carried out aiming to get a deeper understanding of these fluids at the molecular level. The results show that the increase in the number of atoms at the cation ring (from five to six) leads to a decrease in the mutual solubilities with water while increasing their toxicity, and as expected from the well-established relationship between toxicities and hydrophobicities of ILs. The branching of the alkyl chain was observed to decrease the water solubility in ILs, while increasing the ILs solubility in water. The inability of COSMO-RS to correctly predict the effect of branching alkyl chains toward water solubility on them was confirmed using molecular dynamic simulations to be due to the formation of nano-segregated structures of the ILs that are not taken into account by the COSMO-RS model. In addition, the impact of branched alkyl chains on the toxicity is shown to be not trivial and to depend on the aromatic nature of the ILs. PMID:25119425

  4. A COSMO-RS based guide to analyze/quantify the polarity of ionic liquids and their mixtures with organic cosolvents.


    Palomar, José; Torrecilla, José S; Lemus, Jesús; Ferro, Víctor R; Rodríguez, Francisco


    A COSMO-RS descriptor (S(sigma-profile)) has been used in quantitative structure-property relationship (QSPR) studies by a neural network (NN) for the prediction of empirical solvent polarity E(T)(N) scale of neat ionic liquids (ILs) and their mixtures with organic solvents. S(sigma-profile) is a two-dimensional quantum chemical parameter which quantifies the polar electronic charge of chemical structures on the polarity (sigma) scale. Firstly, a radial basis neural network exact fit (RBNN) is successfully optimized for the prediction of E(T)(N), the solvatochromic parameter of a wide variety of neat organic solvents and ILs, including imidazolium, pyridinium, ammonium, phosphonium and pyrrolidinium families, solely using the S(sigma-profile) of individual molecules and ions. Subsequently, a quantitative structure-activity map (QSAM), a new concept recently developed, is proposed as a valuable tool for the molecular understanding of IL polarity, by relating the E(T)(N) polarity parameter to the electronic structure of cations and anions given by quantum-chemical COSMO-RS calculations. Finally, based on the additive character of the S(sigma-profile) descriptor, we propose to simulate the mixture of IL-organic solvents by the estimation of the S(sigma-profile)(Mixture) descriptor, defined as the weighted mean of the S(sigma-profile) values of the components. Then, the E(T)(N) parameters for binary solvent mixtures, including ILs, are accurately predicted using the S(sigma-profile)(Mixture) values from the RBNN model previously developed for pure solvents. As result, we obtain a unique neural network tool to simulate, with similar reliability, the E(T)(N) polarity of a wide variety of pure ILs as well as their mixtures with organic solvents, which exhibit significant positive and negative deviations from ideality. PMID:20145869

  5. CNT loading into cationic cholesterol suspensions show improved DNA binding and serum stability and ability to internalize into cancer cells

    NASA Astrophysics Data System (ADS)

    Chhikara, Bhupender S.; Misra, Santosh K.; Bhattacharya, Santanu


    Methods which disperse single-walled carbon nanotubes (SWNTs) in water as ‘debundled’, while maintaining their unique physical properties are highly useful. We present here a family of cationic cholesterol compounds (Chol+) {Cholest-5en-3?-oxyethyl pyridinium bromide (Chol-PB+), Cholest-5en-3?-oxyethyl N-methyl pyrrolidinium bromide (Chol-MPB+), Cholest-5en-3?-oxyethyl N-methyl morpholinium bromide (Chol-MMB+) and Cholest-5en-3?-oxyethyl diazabicyclo octanium bromide (Chol-DOB+)}. Each of these could be easily dispersed in water. The resulting cationic cholesterol (Chol+) suspensions solubilized single-walled carbon nanotubes (SWCNTs) by the non-specific physical adsorption of Chol+ to form stable, transparent, dark aqueous suspensions at room temperature. Electron microscopy reveals the existence of highly segregated CNTs in these samples. Zeta potential measurements showed an increase in potential of cationic cholesterol aggregates on addition of CNTs. The CNT-Chol+ suspensions were capable of forming stable complexes with genes (DNA) efficiently. The release of double-helical DNA from such CNT-Chol+ complexes could be induced upon the addition of anionic micellar solution of SDS. Furthermore, the CNT-based DNA complexes containing cationic cholesterol aggregates showed higher stability in fetal bovine serum media at physiological conditions. Confocal studies confirm that CNT-Chol+ formulations adhere to HeLa cell surfaces and get internalized more efficiently than the cationic cholesterol suspensions alone (devoid of any CNTs). These cationic cholesterol-CNT suspensions therefore appear to be a promising system for further use in biological applications.

  6. Li+ cation environment, transport, and mechanical properties of the LiTFSI doped N-methyl-N-alkylpyrrolidinium+TFSI- ionic liquids.


    Borodin, Oleg; Smith, Grant D; Henderson, Wesley


    Molecular dynamics (MD) simulations have been performed on N-methyl-N-propylpyrrolidinium bis(trifluoromethanesulfonyl)imide (mppy(+)TFSI(-)) and N,N-dimethyl- pyrrolidinium bis(trifluoromethanesulfonyl)imide (mmpy(+)TFSI(+)) ionic liquids (ILs) doped with 0.25 mol fraction LiTFSI salt at 303-500 K. The liquid density, ion self-diffusion coefficients, and conductivity predicted by MD simulations were found to be in good agreement with experimental data, where available. MD simulations reveal that the Li(+) environment is similar in mppy(+)TFSI(-) and mmpy(+)TFSI(+) ILs doped with LiTFSI. The Li(+) cations were found to be coordinated on average by slightly less than four oxygen atoms with each oxygen atom being contributed by a different TFSI(-) anion. Significant lithium aggregation by sharing up to three TFSI(-) anions bridging two lithiums was observed, particularly at lower temperatures where the lithium aggregates were found to be stable for tens of nanoseconds. Polarization of TFSI(-) anions is largely responsible for the formation of such lithium aggregates. Li(+) transport was found to occur primarily by exchange of TFSI(-) anions in the first coordination shell with a smaller (approximately 30%) contribution also due to Li(+) cations diffusing together with their first coordination shell. In both ILs, ion self-diffusion coefficients followed the order Li(+) < TFSI(-) < mmpy(+) or mppy(+) with all ion diffusion in mmpy(+)TFSI(-) being systematically slower than that in mppy(+)TFSI(-). Conductivity due to the Li(+) cation in LiTFSI doped mppy(+)TFSI(-) IL was found to be greater than that for a model poly(ethylene oxide)(PEO)/LiTFSI polymer electrolyte but significantly lower than that for an ethylene carbonate/LiTFSI liquid electrolyte. Finally, the time-dependent shear modulus for the LiTFSI doped ILs was found to be similar to that for a model poly(ethylene oxide)(PEO)/LiTFSI polymer electrolyte on the subnanosecond time scale. PMID:16927976

  7. Phase behaviour, transport properties, and interactions in Li-salt doped ionic liquids.


    Pitawala, Jagath; Kim, Jae-Kwang; Jacobsson, Per; Koch, Victor; Croce, Fausto; Matic, Aleksandar


    We report on the influence of lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) doping on the glass transition temperature (Tg), the ionic conductivity, and Li-ion coordination of two dicationic ionic liquids (DILs) based on the TFSI anion. The results are compared to the behaviour of traditional mono-cationic ionic liquids. The cations of the DILs contain two imidazolium rings, connected by a decane hydrocarbon chain. Homogeneous mixtures of these ILs and LiTFSI can be obtained in a large concentration range. With increasing Li-salt concentration the ionic conductivity decreases whereas the glass transition temperature increases in both systems. However, the influence of the salt doping on the ionic conductivity and the glass transition temperature is low compared to typical mono-cationic ionic liquids, based on for example the pyrrolidinium cation and the TFSI anion. This behaviour is mirrored in the average coordination number of TFSI anions around Li-ions, determined by Raman spectroscopy. The coordination number is systematically lower in the DILs, suggesting a connection between the difference in the Li-ion environment and the behaviour of the glass transition and the ionic conductivity. A Tg-scaled Arrhenius plot of the ionic conductivity shows that the ionic conductivity for all LiTFSI concentrations has the same temperature dependence, i.e., the fragility of the liquid is the same. This implies that the conduction process is dominated by the viscous properties of the liquids over the entire concentration range. This provides further support for linking the local environment of the Li-ions to the glass transition and conduction process in the ionic liquid/salt mixtures. PMID:22455015

  8. Nonhumidified intermediate temperature fuel cells using protic ionic liquids.


    Lee, Seung-Yul; Ogawa, Atsushi; Kanno, Michihiro; Nakamoto, Hirofumi; Yasuda, Tomohiro; Watanabe, Masayoshi


    In this paper, the characterization of a protic ionic liquid, diethylmethylammonium trifluoromethanesulfonate ([dema][TfO]), as a proton conductor for a fuel cell and the fabrication of a membrane-type fuel cell system using [dema][TfO] under nonhumidified conditions at intermediate temperatures are described in detail. In terms of physicochemical and electrochemical properties, [dema][TfO] exhibits high activity for fuel cell electrode reactions (i.e., the hydrogen oxidation reaction (HOR) and oxygen reduction reaction (ORR)) at a Pt electrode, and the open circuit voltage (OCV) of a liquid fuel cell is 1.03 V at 150 degrees C, as has reported in ref 27. However, diethylmethylammonium bis(trifluoromethane sulfonyl)amide ([dema][NTf(2)]) has relatively low HOR and ORR activity, and thus, the OCV is ca. 0.7 V, although [dema][NTf(2)] and [dema][TfO] have an identical cation ([dema]) and similar thermal and bulk-transport properties. Proton conduction occurs mainly via the vehicle mechanism in [dema][TfO] and the proton transference number (t(+)) is 0.5-0.6. This relatively low t(+) appears to be more disadvantageous for a proton conductor than for other electrolytes such as hydrated sulfonated polymer electrolyte membranes (t(+) = 1.0). However, fast proton-exchange reactions occur between ammonium cations and amines in a model compound. This indicates that the proton-exchange mechanism contributes to the fuel cell system under operation, where deprotonated amines are continuously generated by the cathodic reaction, and that polarization of the cell is avoided. Six-membered sulfonated polyimides in the diethylmethylammonium form exhibit excellent compatibility with [dema][TfO]. The composite membranes can be obtained up to a [dema][TfO] content of 80 wt % and exhibit good thermal stability, high ionic conductivity, and mechanical strength and gas permeation comparable to those of hydrated Nafion. H(2)/O(2) fuel cells prepared using the composite membranes can successfully operate at temperatures from 30 to 140 degrees C under nonhumidified conditions, and a current density of 250 mA cm(-2) is achieved at 120 degrees C. The protic ionic liquid and its composite membrane are a possible candidate for an electrolyte of a H(2)/O(2) fuel cell that operates under nonhumidified conditions. PMID:20578771

  9. Designed Chemical Intervention with Thiols for Prophylactic Contraception

    PubMed Central

    Jain, Ashish; Verma, Vikas; Sharma, Vikas; Kushwaha, Bhavana; Lal, Nand; Kumar, Lalit; Rawat, Tara; Dwivedi, Anil K.; Maikhuri, Jagdamba P.; Sharma, Vishnu L.; Gupta, Gopal


    Unlike somatic cells, sperm have several-fold more available-thiols that are susceptible to redox-active agents. The present study explains the mechanism behind the instant sperm-immobilizing and trichomonacidal activities of pyrrolidinium pyrrolidine-1-carbodithioate (PPC), a novel thiol agent rationally created for prophylactic contraception by minor chemical modifications of some known thiol drugs. PPC, and its three derivatives (with potential active-site blocked by alkylation), were synthesized and evaluated against live human sperm and metronidazole-susceptible and resistant Trichomonas vaginalis, in vitro. Sperm hexokinase activity was evaluated by coupled enzyme assay. PPC irreversibly immobilized 100% human sperm in ?30 seconds and totally eliminated Trichomonas vaginalis more efficiently than nonoxynol-9 and metronidazole. It significantly inhibited (P<0.001) thiol-sensitive sperm hexokinase. However, the molecule completely lost all its biological activities once its thiol group was blocked by alkylation. PPC was subsequently formulated into a mucoadhesive vaginal film using GRaS excipients and evaluated for spermicidal and microbicidal activities (in vitro), and contraceptive efficacy in rabbits. PPC remained fully active in quick-dissolving, mucoadhesive vaginal-film formulation, and these PPC-films significantly reduced pregnancy and fertility rates in rabbits. The films released ?90% of PPC in simulated vaginal fluid (pH 4.2) at 37°C in 5 minutes, in vitro. We have thus discovered a common target (reactive thiols) on chiefly-anaerobic, redox-sensitive cells like sperm and Trichomonas, which is susceptible to designed chemical interference for prophylactic contraception. The active thiol in PPC inactivates sperm and Trichomonas via interference with crucial sulfhydryl-disulfide based reactions, e.g. hexokinase activation in human sperm. In comparison to non-specific surfactant action of OTC spermicide nonoxynol-9, the action of thiol-active PPC is apparently much more specific, potent and safe. PPC presents a proof-of-concept for prophylactic contraception via manipulation of thiols in vagina for selective targeting of sperm and Trichomonas, and qualifies as a promising lead for the development of dually protective vaginal-contraceptive. PMID:23826278

  10. Symposium Report. Battery materials : amorphous carbons and polymer electrolytes.

    SciTech Connect

    Gerald, R. E., II; Chemical Engineering


    The motivation for research in battery materials lies in the expanding consumer demand for compact, high-energy density power sources for portable electronic devices, and environmental issues such as global warming and air pollution that have provided the impetus for mass transportation by electric vehicles. The Battery Materials Symposium, chaired by Jacqueline Johnson (ANL), focused on three topics: the structure and electrochemical properties of new and existing electrolytes, devices for fabricating and investigating thin films, and large-scale computer simulations. The symposium opened with a presentation by the author on a recently invented device for in situ investigations of batteries using nuclear magnetic resonance. Joop Schoonman (Delft University) described several methods for preparing and analyzing thin films made of solid electrolytes. These methods included chemical vapor deposition, electrostatic spray deposition and the Solufill process. Aiichiro Nakano discussed large-scale (10 million to 2 billion atoms) computer simulations of polymer and ceramic systems. An overview was given of a DOE Cooperative Research 2000 program, in the initial stages, that was set up to pursue these atomistic simulations. Doug MacFarlane (Monash University) described conductive plastic crystals based on pyrrolidinium imides. Joseph Pluth (U of Chicago) presented his recent crystallographic studies of Pb compounds found in the ubiquitous lead-acid battery. He showed the structures of tribasic lead sulfate and tetrabasic lead sulfate. Austen Angell (Arizona State Univ.) discussed the general problem of electrolyte polarization in Li-ion battery systems with cation transference numbers less than unity. Steven Greenbaum (Hunter College) provided an introduction of NMR interactions that are useful for investigations of lithium-ion battery materials. Analysis by NMR is nuclear specific, probes local environments and dynamics, and is non-destructive. He discussed {sup 7}Li NMR results of a solid electrolyte system composed of LiI dissolved in PEO. Work on oriented polymer electrolyte samples is ongoing. Yuri Andreev (U. of St. Andrews) gave a historical overview of a number of crystal structures of polymer electrolytes solved using XRD in the group of Peter Bruce. The last speaker of the symposium was Peter Papanek (U. of Pennsylvania). He spoke about various disordered carbon materials used as anodes in Li-ion batteries. He also described his inelastic neutron scattering studies of carbon materials derived from pyrolyzed epoxy novolak resins. His data supports the graphene sheet model and is also consistent with calculations of interior and edge carbon atoms in pyrene that chemically reacted with lithium.

  11. Crystal structures and hydrogen bonding in the proton-transfer salts of nicotine with 3,5-di­nitro­salicylic acid and 5-sulfosalicylic acid

    PubMed Central

    Smith, Graham; Wermuth, Urs D.


    The structures of the 1:1 anhydrous salts of nicotine (NIC) with 3,5-di­nitro­salicylic acid (DNSA) and 5-sulfosalicylic acid (5-SSA), namely (1R,2S)-1-methyl-2-(pyridin-3-yl)-1H-pyrrolidin-1-ium 2-carb­oxy-4,6-di­nitro­phenolate, C10H15N2 +·C7H3N2O7 ?, (I), and (1R,2S)-1-methyl-2-(pyridin-3-yl)-1H-pyrrolidin-1-ium 3-carb­oxy-4-hy­droxy­benzene­sulfonate, C10H15N2 +·C7H5O6S?, (II), are reported. The asymmetric units of both (I) and (II) comprise two independent nicotinium cations (C and D) and either two DNSA or two 5-SSA anions (A and B), respectively. One of the DNSA anions shows a 25% rotational disorder in the benzene ring system. In the crystal of (I), inter-unit pyrrolidinium N—H?Npyridine hydrogen bonds generate zigzag NIC cation chains which extend along a, while the DNSA anions are not involved in any formal inter-species hydrogen bonding but instead form ?–?-associated stacks which are parallel to the NIC cation chains along a [ring-centroid separation = 3.857?(2)?Å]. Weak C—H?O inter­actions between chain substructures give an overall three-dimensional structure. In the crystal of (II), A and B anions form independent zigzag chains with C and D cations, respectively, through carb­oxy­lic acid O—H?Npyridine hydrogen bonds. These chains, which extend along b, are pseudocentrosymmetrically related and give ?–? inter­actions between the benzene rings of anions A and B and the pyridine rings of the NIC cations C and D, respectively [ring centroid separations = 3.6422?(19) and 3.7117?(19)?Å]. Also present are weak C—H?O hydrogen-bonding inter­actions between the chains, giving an overall three-dimensional structure. PMID:25484766