7783-60-0Relevant articles and documents
TEA CO 2 laser-induced isotopically selective dissociation of SF 6 in a cold shock wave
Makarov,Petin
, p. 345 - 350 (2000)
When a pulsed gas dynamically cooled supersonic molecular flow interacts with solid surface a cold shock wave is formed in front of it, non-equilibrium conditions in which may be 'reverse' to those in the incident (unperturbed) flow. Isotopically selective infrared multiphoton dissociation of SF6 in the cold shock wave was studied. Anomalously a large increase (more than one order of magnitude) of the yield of products was found, as compared with the case of excitation of SF6 in unperturbed flow, without essential decrease of the selectivity of process.
Pentafluoronitrosulfane, SF5NO2
Lu, Norman,Thrasher, Joseph S.,Von Ahsen, Stefan,Willner, Helge,Hnyk, Drahomir,Oberhammer, Heinz
, p. 1783 - 1788 (2008/10/09)
The synthesis of pentafluoronitrosulfane, SF5NO2, is accomplished either by reacting N(SF5)3 with NO 2 or by the photolysis of a SF5Br/NO2 mixture using diazo lamps. The product is purified by treatment with CsF and repeated trap-to-trap condensation. The solid compound melts at -78°C, and the extrapolated boiling point is 9°C. SF5NO2 is characterized by 19F, 15N NMR, IR, Raman, and UV spectroscopy as well as by mass spectrometry. The molecular structure of SF 5NO2 is determined by gas electron diffraction. The molecule possesses C2v symmetry with the NO2 group staggering the equatorial S-F bonds and an extremely long 1.903(7) A S-N bond. Calculated bond enthalpies depend strongly on the computational method: 159 (MP2/6-311G++(3df)) and 87 kJ mol-1 (B3LYP/6-311++G-(3df)). The experimental geometry and vibrational spectrum are reproduced reasonably well by quantum chemical calculations.
Quantitative infrared spectroscopic analysis of SF6 decomposition products obtained by electrical partial discharges and sparks using PLS-calibrations
Kurte,Heise,Klockow
, p. 505 - 513 (2007/10/03)
Infrared spectroscopy is a powerful tool for the analysis of gaseous by-products in sulfur hexafluoride gas used as an insulator in high-voltage equipment. Sparks and electrical partial discharges were generated between different point-plane configurations within a custom-made discharge chamber constructed from stainless steel and Teflon. Various electrode materials were used such as stainless steel, copper, aluminium, silver, tungsten and tungsten/copper alloy. Owing to the different electrical conditions, a wide concentration range of the decomposition products existed. The main-products found were the sulfuroxyfluorides SOF4 and SOF2, as well as HF following experiments with partial discharges and sparking with energies around 1.0 J/spark. All infrared spectra were recorded using an FTIR-spectrometer equipped with a 10 cm gas cell. Quantification was carried out using classical least-squares and partial least-squares (PLS) with multivariate spectral data from selected intervals. PLS calibration models were also optimised under the constraint of a minimum number of spectral variables with a view to developing simple photometers based on a restricted number of laser wavelengths. Standard errors of prediction obtained by cross-validation of different PLS calibration models are reported for the compounds mentioned, as well as for SF4, SO2F2 and SiF4.
Spectrum and Mutual Kinetics of HOCH2CH2O2 Radicals
Anastasi, C.,Muir, D. J.,Simpson V. J.
, p. 5791 - 5797 (2007/10/02)
β-Hydroxyethyl peroxy radicals have been studied by using pulse radiolysis to generate the radicals and kinetic absorption to monitor their formation and decay.The ultraviolet absorption spectrum assigned to HOCH2CH2O2 is broadband in nature with a maximum absorption cross section of 3.5 (+/-0.6) * 10-18 cm2 molecule-1 at 230 nm.An overall rate constant for the self-reaction 2 HOCH2CH2O2 -> HOCH2CH2OH + HOCH2CHO + O2 (3a), 2 HOCH2CH2O2 -> 2 HOCH2CH2O + O2 (3b) of k3 = 7.7 (+/-1.2) * 10-12 cm3 molecule-1 s-1 was measured at room temperature together with an estimation of the branching ratio, k3a/k3 = 0.75 (+/-0.1).
Gas-Phase Lewis Acid-Base Interactions. An Experimental Determination of Cyanide Binding Energies from Ion Cyclotron Resonance and High-Pressure Mass Spectrometric Equilibrium Measurements
Larson, J. W.,Szulejko, J. E.,McMahon, T. B.
, p. 7604 - 7609 (2007/10/02)
Both ion cyclotron resonance and high-pressure mass spectrometric equilibrium techniques have been used to investigate the binding energies of anions to a variety of Lewis acids.From an analysis of the enthalpy changes associated with CN- binding it is evident that in cases of relatively weak binding considerable freedom of rotational motion of CN- in the complex may be retained.Ab initio calculations and experiment suggest that binding through both the N and C sites of CN- is nearly equally favorable in some cases.In contrast to results previously obtained for Bronsted acids which showed that CN- and Cl- bind nearly identically, the present data for Lewis acids show many cases where cyanide is much more favorably bound than chloride, a consequence of enhanced covalent binding of the CN- complexes.New Kroeger Drago parameters derived for CN- support the importance of covalent binding in cyanide adducts.Correlations of binding energy of anions to Lewis acids with the anion proton affinity show excellent linear relationships which may be used to predict binding energetics for new anions.
Preparation and characterization of chlorodifluorosulfur(IV) hexafluoroarsenate
Alam, Kohrshed,Shreeve, Jean'ne M.
, p. 1374 - 1375 (2008/10/08)
The stable salt [SF2Cl]+[AsF6]- was prepared and isolated in good yield from the reaction of trans-CF3SF4Cl and AsF5. The identity and ionic nature of this salt were established by its elemental analysis and by 19F NMR, IR, and mass spectral studies. Redistribution of the halogen atoms in the cation of [SF2Cl]+[AsF6]- to form [SF3]+[AsF6]- and [SCl3]+[AsF6]- in liquid SO2 occurred at ambient temperature. In the presence of NaF or NaCl, [SF2Cl]+ was converted to [SF3Cl] or [SF2Cl2], respectively, at low temperature, where redistribution occurred to form SF4 and [SCl4].
Attempted Synthesis of Osmium(VI) and Iridium(VI) Thiofluorides; the Preparation of OsF5.SF4 and IrF5.SF4
Holloway, John. H,Rook, John
, p. 2285 - 2288 (2007/10/02)
The interaction of OsF4 or IrF4 with ZnS or B2S3 at elevated temperature yields the adducts OsF5.SF4 and IrF5.SF4 rather than the trasition-metal thiofluorides.Infrared and X-ray powder diffraction studies indicate that the adducts have contributions to the bonding from the ionic formulations +- and +- and there is also (19)F n.m.r. evidence for the latter in solution in anhydrous HF.
Ion Chemistry and Electron Affinity of WF6
Viggiano, A. A.,Paulson, John, F.,Dale, Fred,Henchman, Michael,Adams,N. G.,Smith, D.
, p. 2264 - 2267 (2007/10/02)
The rate coefficients and branching ratios have been measured for the reactions of WF6 with F(-),Cl(1-), Br(1-), I(1-),CN(1-),NO3(1-), NO2(1-),SF5(1-) and SF6(1-).WF6 was found to react rapidly with these ions.Three channels were observed: asociation, cha
INTERACTION BETWEEN URANIUM PENTAFLUORIDE AND THE PENTAFLUORIDES OF VANADIUM, ARSENIC, NIOBIUM, TANTALUM, AND BISMUTH, AND THE TETRAFLUORIDE OF SULPHUR
Holloway, John H.,Staunton, Garry M.,Rediess, Klaus,Bougon, Roland,Brown, David
, p. 2163 - 2166 (2007/10/02)
The interaction of UF5 with SF4, SF4O, and some Lewis-acid pentafluorides of various strengths has been studied.In anhydrous HF solutions, SF4 was shown to yield an adduct of composition 3UF5*SF4 in which both ionic and fluorine-bridged species are present.The pentafluorides of arsenic, tantalum, and niobium combine with UF5 to give adducts of composition 1.5 UF5*AsF5, UF5*2TaF5, and UF5*2NbF5, respectively.The arsenic derivative is stable at room temperature only under a pressure of AsF5, whereas the tantalum and niobium adducts decompose at higher temperature forming UF5*TaF5 and UF5*NbF5, respectively.Vibrational spectroscopic study of the pentafluoride adducts of UF5 has shown that they consist of covalent fluorine-bridged species.Uranium pentafluoride is fluorinated at room temperature by VF5 and by BiF5 in anhydrous HF.
