Lithium-cyclo-difluoromethane-1,1-bis(sulfonyl)imide as a stabilizing electrolyte additive for improved high voltage applications in lithium-ion batteries.

Lithium-cyclo-difluoromethane-1,1-bis(sulfonyl)imide (LiDMSI) was evaluated as an electrolyte additive in lithium-ion batteries for improved high voltage applications. Cycling the cathode at high potentials leads to the electrochemical oxidation of the salt to form a cathode electrolyte interphase (CEI) layer on the cathode surface. With the addition of 2 wt% of LiDMSI to the 1 M LiPF6 in 1 : 1 (by wt) EC : DEC electrolyte, the capacity retention and the Coulombic efficiency in LiNi1/3Co1/3Mn1/3O2/Li-half-cells as well as in LiNi1/3Co1/3Mn1/3O2/graphite-full-cells were improved. The cycling results point out the less over-potential and resistance at the cathode/electrolyte interface. These improvements are studied by SEM, EIS and XPS techniques.

Interaction of ionic liquids ions with natural cyclodextrins.

The interaction of natural α-, ß-, and γ-cyclodextrins (CDs) with 14 hydrophobic ionic moieties of ionic liquids (ILs) was systematically examined in dilute aqueous solutions using isothermal titration microcalorimetry (ITC) and NMR spectroscopy. The studied cationic and anionic moieties involved some recently developed heavily fluorinated structures, as well as some others of common use. To isolate the effect of a given ion, the measurements were performed on salts containing the hydrophobic IL ion in question and a complexation-inactive counterion. Additional ITC experiments on ILs whose both cation and anion can interact appreciably with the CD cavity demonstrated that to resolve the effect of individual ions from such data is generally a tricky task and confirmed the superiority of the isolation strategy adopted for the purpose throughout this work. The binding constant, enthalpy and entropy determined at 298.15 K for the 1:1 (ion:CD) inclusion complex formation range in broad limits, being 0 < K < 2 × 10(5), 0 < -Δ(r)H°/(kJ·mol(-1)) < 44, and -28 < TΔ(r)S°/(kJ·mol(-1)) < 14, respectively. The stabilities of complexes of perfluorohexyl bearing ions with ß-CD belong to the highest ever observed with natural CDs in water. The established binding affinity scales were discussed in both thermodynamic and molecular terms. The concepts of hydrophobic interaction and guest-host size matching supported by simple molecular modeling proved useful to rationalize the observed widely different binding affinities and suggest possible binding modes. Enthalpy and entropy contributions to the stability of the ion-CD complexes were found to compensate each other considerably obeying more or less the linear compensation relationship marked by existing literature data on binding other guests to natural CDs. As outliers to this pattern, the most stable complexes of -C(6)F(13) bearing ions with ß-CD were found to receive an enhanced inherent entropy stabilization due to extraordinarily high extent of desolvation occurring in the course of binding.

The Bis(pentafluoroethyl)phosphinous acid (C2F5)2POH.

The industrial product (C(2)F(5))(3)PF(2) is transformed into the phosphinic acid chloride (C(2)F(5))(2)P(O)Cl, which reacts with an excess of Bu(3)SnH in a clean, multistep reaction to give the stannyl derivative (C(2)F(5))(2)POSnBu(3). Subsequent treatment with gaseous HBr leads to the formation of (C(2)F(5))(2)POH, which is isolated in 70 % yield. Besides (CF(3))(2)POH, bis(pentafluoroethyl)phosphinous acid, (C(2)F(5))(2)POH, represents the second known example of a phosphinous acid that is predicted by using density functional theory calculations at the B3PW91/6-311G(3d,p) level to be more stable than the phosphane oxide tautomer, the energy difference being 11.7 kJ mol(-1). Only the phosphinous acid isomer is detectable in the gas phase and in solution. However, investigations of the neat liquid reveal a temperature-dependent tautomeric equilibrium with the phosphane oxide isomer (C(2)F(5))(2)P(O)H, which is characterized by vibrational and multinuclear NMR spectroscopic methods in combination with quantum-chemical calculations.

omega-(Bis(trifluoromethyl)amino)alkane-1-sulfonates: synthesis and mass spectrometric study of the biotransformation products.

In search of fluorinated functional groups which could undergo defluorination, and therefore be included in novel non-polluting fluorinated surfactants, omega-(bis(trifluoromethyl)amino)alkane-1-sulfonates (BTFMA-AS) with a homologue distribution from seven to thirteen methylene groups were synthesized and investigated for aerobic biodegradation applying both a standardized test and a fixed-bed bioreactor (FBBR). These compounds were prepared as part of a screening study for potentially mineralizable fluorinated endgroups.Application of hybrid triple quadrupole-linear ion trap mass spectrometry (QqQ(LIT)-MS) coupled to high-performance liquid chromatography (HPLC) allowed the tracking of primary degradation as well as the detection and structural elucidation of biotransformation intermediates. An understanding of the fragmentation pathway of the test compounds allowed selective precursor ion scans to reveal the presence of stable fluorinated metabolites. Structures were confirmed by enhanced product ion scans and MS(3) scans in the linear ion trap mode.The primary biodegradation rate and the extent of biodegradation were found to be chain-length dependent, with higher homologues being completely primarily degraded within 10 days. For the first time, two simultaneous metabolic pathways for substituted linear alkane-1-sulfonates were discovered: Desulfonation, oxidation to a carboxylic acid and subsequent chain-length shortening by beta-oxidation dominated the metabolism. This pathway resulted in the formation of 3-(bis(trifluoromethyl)amino)propionic acid and bis(trifluoromethyl)aminoacetic acid, which showed recalcitrance in this experiment. Oxidation of the alkyl chain to the respective carbonyl derivative represents the minor pathway. Only the long-chain homologues of these oxidized species were partially degraded; the short-chain homologues were not attacked.

Synthesis and characterization of bis[bis(pentafluoroethyl)phosphinyl]imides, M(+)N[(C2F5)2P(O)]2(-), M = H, Na, K, Cs, Ag, Me4N.

A convenient synthesis and a full characterization of the strong acid bis[bis(pentafluoroethyl)phosphinyl]imide and some of its salts M (+)N[(C 2F 5) 2P(O)] 2 (-), M = Na, K, Cs, Ag, Me 4N, are presented. Their thermal (mp, T dec.) and spectroscopic (IR, Raman, NMR) properties are discussed. A single crystal structure of [Me 4N][N{P(O)(C 2F 5) 2} 2] has been obtained, and the structural parameters of the anion are compared with the results of quantum-chemical calculations. The observed properties are comparable to those of bis((trifluoromethyl)sulfonyl)imide and their derivatives.

Global mineralogical and aqueous mars history derived from OMEGA/Mars Express data.

Global mineralogical mapping of Mars by the Observatoire pour la Mineralogie, l'Eau, les Glaces et l'Activité (OMEGA) instrument on the European Space Agency's Mars Express spacecraft provides new information on Mars' geological and climatic history. Phyllosilicates formed by aqueous alteration very early in the planet's history (the "phyllocian" era) are found in the oldest terrains; sulfates were formed in a second era (the "theiikian" era) in an acidic environment. Beginning about 3.5 billion years ago, the last era (the "siderikian") is dominated by the formation of anhydrous ferric oxides in a slow superficial weathering, without liquid water playing a major role across the planet.

Detection of methane in the atmosphere of Mars.

We report a detection of methane in the martian atmosphere by the Planetary Fourier Spectrometer onboard the Mars Express spacecraft. The global average methane mixing ratio is found to be 10 +/- 5 parts per billion by volume (ppbv). However, the mixing ratio varies between 0 and 30 ppbv over the planet. The source of methane could be either biogenic or nonbiogenic, including past or present subsurface microorganisms, hydrothermal activity, or cometary impacts.