Physical properties of a new Deep Eutectic Solvent based on lithium bis[(trifluoromethyl)sulfonyl]imide and N-methylacetamide as superionic suitable electrolyte for lithium ion batteries and electric double layer capacitors

Herein we present a study on the physical/chemical properties of a new Deep Eutectic Solvent (DES) based on N-methylacetamide (MAc) and lithium bis[(trifluoromethyl)sulfonyl]imide (LiTFSI). Due to its interesting properties, such as wide liquid-phase range from -60°C to 280°C, low vapor pressure, and high ionic conductivity up to 28.4mScm at 150°C and at x=1/4, this solution can be practically used as electrolyte for electrochemical storage systems such as electric double-layer capacitors (EDLCs) and/or lithium ion batteries (LiBs). Firstly, relationships between its transport properties (conductivity and viscosity) as a function of composition and temperature were discussed through Arrhenius' Law and Vogel-Tamman-Fulcher (VTF) equations, as well as by using the Walden classification. From this investigation, it appears that this complex electrolyte possesses a number of excellent transport properties, like a superionic character for example. Based on which, we then evaluated its electrochemical performances as electrolyte for EDLCs and LiBs applications by using activated carbon (AC) and lithium iron phosphate (LiFePO) electrodes, respectively. These results demonstrate that this electrolyte has a good compatibility with both electrodes (AC and LiFePO) in each testing cell driven also by excellent electrochemical properties in specific capacitance, rate and cycling performances, indicating that the LiTFSI/MAc DES can be a promising electrolyte for EDLCs and LiBs applications especially for those requiring high safety and stability. © 2013 Elsevier Ltd.

Being observant and observed: embodied citizenship training in the Home Guard and the Boy Scout Movement, 1907-1945

Building upon recent studies by geographers and social scientists on the everyday practices of (scientific) observation, this paper focuses on the role of two distinct, yet similar organisations that held observation as an essential and 'automatic' embodied skill. Utilising the examples of Home Guard camouflage and the Boy Scout Movement, the paper critically examines how these organisations sought to articulate the individual as both observer and observed, thereby exposing a much more complex entanglement of different visual positions and practices hitherto neglected in studies of observation. Moreover, the paper emphasises the importance of the act of 'not-being-seen' as a complementary and fundamental aspect of (non-)observational practice, accentuated and promoted by civic institutions in terms of duty and responsibility. Finally, the paper considers the evolutionary aspects of observation through the lifecourse, revealing a complex, relational geography of expertise, experience and skill that crossed age-distinctions. © 2012 Elsevier Ltd.

Comparative evaluation of 2,3-bis [2-methyloxy-4-nitro-5-sulfophenyl]-2H-tetrazolium-5-carboxanilide (XTT) and 2-(2-methoxy-4-nitrophenyl)-3-(4-nitrophenyl)-5-(2, 4-disulfophenyl)-2H-tetrazolium, monosodium salt (WST-8) rapid colorimetric assays for antimicrobial susceptibility testing of staphylococci and ESBL-producing clinical isolates

A new generation of water soluble tetrazolium salts have recently become available and in this study we compared a colorimetric assay developed using one of these salts, 2-(2-methoxy-4-nitrophenyl)-3-(4-nitrophenyl)-5-(2, 4-disulfophenyl)-2H-tetrazolium, monosodium salt (WST-8), with a previously developed 2,3-bis [2-methyloxy-4-nitro-5-sulfophenyl]-2H-tetrazolium-5-carboxanilide (XTT) colorimetric assay to determine which agent is most suitable for use as a colorimetric indicator in susceptibility testing. The MICs of 6 antibiotics were determined for 33 staphylococci using both colorimetric assays and compared with those obtained using the British Society for Antimicrobial Chemotherapy reference broth microdilution method. Absolute categorical agreement between the reference and test methods ranged from 79% (cefuroxime) to 100% (vancomycin) for both assays. No minor or major errors occurred using either assay with very major errors ranging from zero (vancomycin) to seven (cefuroxime). Analysis of the distribution of differences in the log2 dilution MIC results revealed overall agreement, within the accuracy limits of the standard test (± 1 log2 dilution), using the XTT and WST-8 assays of 98% and 88%, respectively. Further studies on 31 ESBL-producing isolates were performed using the XTT method with absolute categorical agreement ranging from 87% (nitrofurantoin) to 100% (ofloxacin and meropenem). No errors were noted for either ofloxacin or meropenem with overall agreement of 91%. The data suggests that XTT is more reliable and accurate than WST-8 for use in a rapid antimicrobial susceptibility test.

An efficient Cu(II)-bis(oxazoline)-based polymer immobilised ionic liquid phase catalyst for asymmetric carbon–carbon bond formation

The asymmetric Diels-Alder reaction between N-acryloyloxazolidinone and cyclopentadiene and the Mukaiyama-aldol reaction between methylpyruvate and 1-phenyl-1-trimethylsilyloxyethene have been catalysed by heterogeneous copper(II)-bis(oxazoline)-based polymer immobilised ionic liquid phase (PIILP) systems generated from a range of linear and cross linked ionic polymers. In both reactions selectivity and ee were strongly influenced by the choice of polymer. A comparison of the performance of a range of Cu(II)-bis(oxazoline)-PIILP catalyst systems against analogous supported ionic liquid phase (SILP) heterogeneous catalysts as well as their homogeneous counterparts has been undertaken and their relative merits evaluated.

Dynamics of excess electronic charge in aliphatic ionic liquids containing the bis(trifluoromethylsulfonyl)amide anion

In a recent article (J. Am. Chem. Soc. 2011, 133, 20186) we investigated the initial spatial distribution of dry excess electrons in a series of room-temperature ionic liquids (RTILs). Perhaps unexpectedly, we found that in some alkylammonium-based systems the excess negative charge resided on anions and not on the positive cations. Following on these results, in the current paper we describe the time evolution of an excess electronic charge introduced in alkylammonium- and pyrrolidinium-based ionic liquids coupled with the bis(trifluoromethylsulfonyl)amide ([TfN]) anion. We find that on a 50 fs time scale an initially delocalized excess electron localizes on a single [TfN] anion which begins a fragmentation process. Low-energy transitions have a very different physical origin on the several femtoseconds time scale when compared to what occurs on the picosecond time scale. At time zero, these are intraband transitions of the excess electron. However after 40 fs when the excess electronic charge localizes on a single anion, these transitions disappear, and the spectrum is dominated by electron-transfer transitions between the fragments of the doubly charged breaking anion. © 2013 American Chemical Society.

Electrical conductivity and glass formation in nitrile-functionalized pyrrolidinium bis(trifluoromethylsulfonyl)imide ionic liquids: chain length and odd–even effects of the alkyl spacer between the pyrrolidinium ring and the nitrile group

The electrical conductivity of a series of pyrrolidinium bis(trifluoromethylsulfonyl)imide ionic liquids, functionalized with a nitrile (cyano) group at the end of an alkyl chain attached to the cation, was studied in the temperature range between 173 K and 393 K. The glass formation of the ionic liquids is influenced by the length of the alkyl spacer separating the nitrile function from the pyrrolidinium ring. The electrical conductivity and the viscosity do not show a monotonic dependence on the alkyl spacer length, but rather an odd-even effect. An explanation for this behavior is given, including the potential energy landscape picture for the glass transition.

Di-mu-chloro-bis({2-[(2-hydroxyethyl)iminomethyl]phenolato-kappa N-3,O,O '} nickel(II)) methanol solvate

The title compound, [Ni2Cl2(C9H10NO2)(2)]center dot CH3OH, is a dinuclear unit built up by two nickel(II) complexes, bridged by two Cl atoms. The coordination geometry around each Ni-II atom can be considered as distorted square-pyramidal, with the tridendate chelate Schiff base ligands coordinating in a trans conformation through their imine N atom and phenoxy and alkoxy O atoms.

mu-pyrazine-kappa N-2 : N '-bis[diiodomercury(II)]

In [Hg2I4(Pyp)] (Pyp = pyrazine, C4H4N2), centrosymmetric molecules consist of two HgI2 units connected by a pyrazine molecule.

Bis(tetraethylammonium) decachloro-tetramercurate(II), (Et4N)(2)[Hg4Cl10]

The structure of (Et4N)(2)[Hg4Cl10] contains dinuclear [Hg2Cl6](2-) anions and HgCl2 molecules, with definite interactions so that the anion can also be formulated as [Hg4Cl10](2-). Alternatively the compound can be written as (Et4N)(2)[Hg2Cl6][HgCl2](2). Charge balance is achieved by ordered [Et4N](+) cations. An inversion centre is situated at the centre of the [Hg2Cl6](2-) anions.

Bis(tetraethylammonium) di-mu-bromo-bis[dibromomercurate(II)], (Et4N)(2)[Hg2Br6]

The structure of (Et4N)(2)[Hg2Br6] contains dinuclear [Hg2Br6](2-) species as isolated anions. Charge balance is achieved by ordered [Et4N](+) cations. An inversion centre is located at the centre of the [Hg2Br6](2-) unit.

Bis(tetraethylammonium) octabromo-trimercurate(II), (Et4N)(2)[Hg3Br8]

The structure of (Et4N)(2)[Hg3Br8] contains isolated dinuclear [Hg2Br6](2-) anions and neutral HgBr2 molecules. Charge balance is achieved by ordered [Et4N](+) cations. The formula may therefore be written as (Et4N)(2)[Hg2Br6][HgBr2]. The N atoms of the (Et4N)(+) ions lie on a (4) over bar axis along [001] and, whereas one of the mercury(II) ions is placed on a mirror plane perpendicular to the c axis, the second one is located on a special position of site symmetry 2/m.

'Whatever You Say, Say Nothing' : Researching Memory & Identity in Mid-Ulster, 1945-1969

The influence of collective memory on political identity in Ireland has been well documented. It has particular force in Northern Ireland where there is fundamental disagreement about how and why the conflict erupted and how it should be resolved. This article outlines some of the issues encountered by an ‘insider’ when attempting to record and analyse the conflicting memories of a range of Protestants and Catholics who grew up in Mid-Ulster in the decades preceding the Troubles. In particular, it considers the challenges and opportunities presented by a two-pronged approach to oral history: using testimony as evidence about historical experience in the past and as evidence about historical memory – both collective and individual – in the present.

The solution structure of 1:2 phenol/N-methylpyridinium bis{(trifluoromethyl)sulfonyl}imide liquid mixtures

Neutron diffraction has been used to investigate the liquid structure of a 1:2 solution of phenol in the ionic liquid N-methylpyridinium bis{(trifluoromethyl)sulfonyl}imide at 60 ◦C, using the empirical potential structure refinement (EPSR) process to model the data obtained from the SANDALS diffractometer at ISIS. Addition of phenol results in suppression of the melting point of the pyridinium salt and formation of a room temperature solution with aromatic phenol–cation and phenol-OH to anion hydrogen-bonding interactions.

Use of water in aiding olefin/paraffin (liquid + liquid) extraction via complexation with a silver bis(trifluoromethylsulfonyl)imide salt

This paper describes the extraction of C₅–C₈ linear α-olefins from olefin/paraffin mixtures of the same carbon number via a reversible complexation with a silver salt (silver bis(trifluoromethylsulfonyl)imide, Ag[Tf₂N]) to form room temperature ionic liquids [Ag(olefin)_x][Tf₂N]. From the experimental (liquid + liquid) equilibrium data for the olefin/paraffin mixtures and Ag[Tf₂N], 1-pentene showed the best separation performance while C₇ and C₈ olefins could only be separated from the corresponding mixtures on addition of water which also improves the selectivity at lower carbon numbers like the C₅ and C₆, for example. Using infrared and Raman spectroscopy of the complex and Ag[Tf₂N] saturated by olefin, the mechanism of the extraction was found to be based on both chemical complexation and the physical solubility of the olefin in the ionic liquid ([Ag(olefin)_x][Tf₂N]). These experiments further support the use of such extraction techniques for the separation of olefins from paraffins.

Excess molar volumes and excess molar enthalpies in binary systems N-alkyl-triethylammonium bis(trifluoromethylsulfonyl)imide plus methanol

In the present paper, a study on the influence of the alkyl chain length in N-alkyl-triethylammonium bis(trifluoromethylsulfonyl)imide ionic liquids, [N_R,222][Tf₂N] (R   = 6, 8 or 12), on the excess molar enthalpy at 303.15 K and excess molar volume within the temperature interval (283.15–338.15 K) of ionic liquid + methanol mixtures is carried out. Small excess molar volumes with highly asymmetric curves (i.e. S-shape) as a function of mole fraction composition were obtained, with negative values showing in the methanol-rich regions. The excess molar volumes increase with the increase of the alkyl-chain length of the ammonium cation of the ionic liquid and decrease with temperature. The excess enthalpies of selected binary mixtures are positive over the whole composition range and increase slightly with the length of the alkyl side-chain of the cation on the ionic liquid. Both excess properties were subsequently correlated using a Redlich–Kister-type equation, as well as by using the ERAS model. From this semipredictive model the studied excess quantities could be obtained from its chemical and physical contribution. Finally, the COSMOThermX software has been used to evaluate its prediction capability on the excess enthalpy for investigated mixtures at 303.15 K and 0.1 MPa. From this work, it appears that COSMOThermX method predicts this property with good accuracy of approx. 10%, providing at the same time the correct order of magnitude of the partial molar excess enthalpies at infinite dilution for the studied ILs,