Fluorine-containing Anions Research Articles

Surface interactions and tribochemical processes in Ionic Liquid lubrication of aluminium-steel contacts

Room-temperature Ionic Liquids (ILs) are being studied as new lubricants in a variety of sliding contacts. One of their more interesting tribological applications is that of steel-aluminium lubrication. In this work we present the surface interaction mechanisms and tribocorrosion processes which have been found in the use of ILs formed by a 1-alkyl-3-methylimidazolium cation and a fluorine-containing anion as neat lubricants of 52100 steel-2011 aluminium pairs. The results obtained by electron microscopy (SEM), Energy Disperssive Spectroscopy (EDS) and X-ray Photoelectron Spectroscopy (XPS) techniques are discussed as functions of Ionic Liquid (IL) composition and properties.

Electronic Structure of Ionic Liquids Studied by UV Photoemission and Inverse Photoemission Spectroscopy

ABSTRACTElectronic structures of the ionic liquids were studied by ultraviolet photoemission spectroscopy (UPS) and inverse photoemission spectroscopy (IPES). The sample materials contain 1-buthyl-3-alkylimidazolium ion [Cnmim]+ (n=4, 8, 10) as the cation in combination with fluorine-containing anions (tetrafluoroboronate BF4−, hexafluorophosphate PF6−). Comparing the calculated density of states with the observed spectra, we found that the ionization thresholds of these ionic liquids are determined by the highest occupied molecular orbitals (HOMO) of the cation, although the calculated HOMOs of the isolated anions are higher than that of isolated cation. The combination of the UPS and IPES results reveals that the band gaps of these ionic liquids are determined by only cation.

Density functional theory study on lithium bis[1,2-benzenediolato(2-)- O, O′] borate and its derivatives: electronic structures, energies, and molecular properties

Theoretical studies on electrolyte salts, lithium bis[1,2-benzenediolato(2-)- O, O′] borate (LBBB) and its derivatives, lithium bis[3-fluoro-1,2-benzenediolato(2-)- O, O′]borate (1FLBBB), and lithium bis[tetrafluoro-1,2-benzenediolato(2-)- O, O′] borate(4FLBBB) are carried out using density functional theory (DFT) method and B3LYP theory level for the first time. Bidentate structures involving two oxygen atoms are preferred. The GIAO–DFT results for all molecules suggest that the corresponding RB3LYP/6-31++G(2df,2p) geometries can be deemed reasonably good representations of the geometries of relatively free molecules in solution. Based on these conformations, a linear correlation was observed between the highest occupied molecular orbital (HOMO) energies and the limiting oxidation potentials measured by linear sweep voltammetry, which supports experimental results that inorganic fluorine-containing anions are more resistant against oxidation than their organic counterparts. The correlations were also observed between ionic conductivity and binding energy, solubility and anion polarizability , thermal stability and the energy difference between E LUMO and E HOMO. Wave function analyses have been performed by natural bond orbital (NBO) method to further investigate the cation–anion interactions.

Quaternary Trialkyl(polyfluoroalkyl)ammonium Salts Including Liquid Iodides.

AbstractFor Abstract see ChemInform Abstract in Full Text.

Quaternary trialkyl(polyfluoroalkyl)ammonium salts including liquid iodides

New quaternary ammonium salts that contain polyfluorinated alkyl substituents were prepared by the polyfluoroalkylation of tertiary amines with polyfluorinated alkyl iodides. Metathesis reactions of the iodide salts with fluorine-containing anions resulted in new low melting salts. The iodide salts of the tri(isooctyl)polyfluoroalkyl amines are also liquids at 25°C.

New Quaternary Polyfluoroalkyl‐1,2,4‐triazolium Salts Leading to Ionic Liquids.

AbstractFor Abstract see ChemInform Abstract in Full Text.

New Quaternary Polyfluoroalkyl-1,2,4-Triazolium Salts Leading to Ionic Liquids

1-Alkyl-1,2,4-triazoles were quaternized at N-4 in >98% isolated yields using polyfluoroalkyl halides under neat reaction conditions at 100-120 °C to form 1-R-4-R t -triazolium (Taz) halides. Metathesis of these polyfluoroalkylated triazolium halides with fluorine-containing anions led to the formation of new ionic liquids, [R(Rf)Taz] + Y - .

Anodic Stability of Several Anions Examined by Ab Initio Molecular Orbital and Density Functional Theories

The anodic stability of anions is an important factor in determining the maximum operating voltage of lithium-ion cells, if appreciable degradation is to be avoided. A linear correlation was observed between the highest occupied molecular orbital energies calculated by ab initio molecular orbital theory [HF/6-31G(d), and the limiting oxidation potentials measured by linear sweep voltammetry, which supports experimental results that inorganic fluorine-containing anions are more resistant against oxidation than their organic counterparts: The ionization potentials of these anions were also calculated from the energy difference between the anion and the neutral radical by ab initio density functional theory [B3LYP/6-31G(d), This high accuracy procedure explained the subtle energy difference between and © 2002 The Electrochemical Society. All rights reserved.

Collidinium- und Imidazolium-Salze Fluor-haltiger Anionen. Die Kristallstruktur von [CollH]2 [AsF6][As2 F11] (Coll = 2,4,6-Trimethylpyridin) / Collidinium and Imidazolium Salts of Fluorine-Containing Anions. The Crystal Structure of [CollH]2[AsF6][As2F11] (Coll = 2,4,6-Trimethylpyridine)

Abstract Die Kristall­ struktur von [CollH]2 [AsF6][As2F11] (Coll = 2,4,6-Trimethylpyridin) Collidinium and Imidazolium Salts of Fluorine-Containing Anions. The Crystal Structure of [CollH]2[AsF6][As2F11] (Coll = 2,4,6-Trimethylpyridine) From s-Collidine (1, Coll) and aqueous HF compounds of the composition Coll · n HF (n = 1 -2) are formed which are transformed to [CollH]+ [HF2]- (2) by sublimation. [CollH]2[AsF6][As2F] J (3) is obtained from 1 and the superacid system HF/AsF5. 2 reacts with 2,3-dihydro-l,3-diisopropyl-4,5-dimethylimidazol-2-ylidene (4, Im) to give the imidazo­ lium salt [ImH]+ [HF2]- (5). Hydrogen bonds in the crystal structure of [CollH]2[AsF6][As2Fn ] (3) are discussed.

Latest trends in the introduction of fluorine-containing anions into organic molecules

Recent progress in investigations of the reactivity of the CF 3SiMe 3/TASF system, amido- and alkylamidophosphites to different type of electrophiles will be reported. The processes developed make it possible to introduce into organic molecules a range of fluorinated anions of a broad spectrum of nucleophilicity. The possible mechanism of the reactions, and spectral and single crystal X-ray data of the compounds obtained are discussed.

Coordinated water/anion hydrogen bonds and Pd-H bond acidity in cationic palladium(II) aquo hydrides and the x-ray crystal and molecular structures of trans-[(Cy3P)2Pd(H)(H2O)]BF4 (Cy = cyclohexyl)

Palladium (II) bis(tricyclohexylphosphine) cationic hydrides have been obtained by oxidative addition of the strong acids [H 3 O + ] [BF 3 OH − ] or [H 3 O + ] [BF 4 − ] to (PCy 3 ) 2 Pd, 1; by this route, the compounds trans-[(Cy 3 P) 2 Pd(H)(H 2 O)]X (X=BF 3 OH, 2; X=BF 4 , 4) have been isolated and characterized. A strong dependence of the stability of trans-[(Cy 3 P) 2 Pd(H)(L)]X complexes upon the L-X combinations was observed. When L=H 2 O, stable cationic hydrides are obtainable only with fluorine-containing anions (BF 3 OH − , BF 4 − , or PF 6 − ), while immediate decomposition to 1 was observed when the metathesis of X − with BPh 4 − or B(n-Bu) 4 − was attempted

Solvate isotope NMR shifts of anion fluorocomplexes

A study of 19F NMR solvate isotope shifts of several inorganic fluorocomplexes of group II, III, IV, V and VI metals has been carried out. The isotope shifts were compared with effective charges and their distribution in fluorine-containing anions. The possibility of using 19F solvate isotope shifts to establish unfamiliar complex anions and their hydration is discussed.