- Rotational spectrum and molecular properties of the dinitrogen-chlorine monofluoride complex
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The ground-state rotational spectra of the three isotopomers 14N2...35ClF, 15N2...35ClF and 15N2...37ClF of a complex formed by dinitrogen and chlorine monofluoride have been observed with a pulsed-nozzle, Fourier-transform microwave spectrometer. The spectroscopic constants B0, DJ, χaa(A) (A) = 14Ni, 14No or Cl) and Mbb(Cl) are reported. The complex is shown to have a linear (or nearly linear) arrangement NoNi...ClF of the nuclei in the equilibrium conformation with r(Ni...Cl) = 2.920(2) A. The intermolecular stretching force constant, kσ = 5.00(5) N m-1, is implied by the centrifugal distortion constant DJ. Intepretation of the nuclear quadrupole coupling constants χaa(A) leads to the oscillation angles θav = cos-1〈cos2 θ〉1/2 = 17.8(5)° and φav = cos-1〈cos2 θ〉1/2 = 10(3)° for the N2 and ClF subunits, respectively. Additionally, the diffence χaa(Ni) - χaa(No) leads, on the basis of a simple model, to the conclusion that the polarisation of N2 attending complex formation is equivalent to the transfer of a fraction δ ≈ 0.02 of an electronic charge from No to Ni. A comparison of the properties of four related complexes N2...YF and OC...YF, where Y = Cl or H, is presented.
- Cooke, Stephen A.,Cotti, Gina,Hinds, Kelvin,Holloway, John H.,Legon,Lister, David G.
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- The complex OC...ClF identified as a pre-chemical intermediate by rotational spectroscopy of carbon monoxide-chlorine monofluoride mixtures
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The ground-state rotational spectra of four isotopomers of the complex OC...ClF have been observed by using a fast-mixing nozzle in a pulsed-nozzle, Fourier-transform microwave spectrometer. The spectrum of the reaction product carbonyl chloride fluoride was detected but its intensity indicated that the extent of the reaction was small. The observed spectroscopic constants B(0), D(J), χ(aa)(Cl) and M(bb)(Cl) were interpretedto show that the pre-chemical complex has the nuclei collinear in the o rder OC...ClF, with r(C...Cl)=2.770(3)? and the intermolecular stretching force constant k(σ)=7.03(3) N m**-1. There is only a minor electric charge redistribution within ClF on complex formation.
- Hinds, K.,Holloway, J. H.,Legon, A. C.
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- From hypochlorites to perfluorinated dialkyl peroxides
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The synthesis and characterization of the new perfluorinated hypochlorite, undecafluoro-tert-pentyl hypochlorite, (C2F5)(F3C)2COCl, is reported. Its gas-phase infrared, UV/Vis and NMR spectra have been recorded and its spectroscopic properties are discussed and compared with quantum-chemical predictions and those of other known perfluorinated hypochlorites such as RFOCl [RF = F3C, (F3C)3C, (C2F5)(F3C)2C]. A synthetic route to otherwise difficult to access perfluorinated dialkyl peroxides, RFOORF, is also provided by low-temperature photolysis of the corresponding hypochlorite.
- Nissen, Jan H.,Wickemeyer, Lucas,Stüker, Tony,Steinhauer, Simon,Beckers, Helmut,Riedel, Sebastian
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supporting information
(2019/12/26)
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- Kinetic mechanism of ClONO2 uptake on polycrystalline film of NaCl
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Kinetic studies and the mechanism determination of ClONO2 uptake on polycrystalline NaCl were carried out using a coated-insert flow tube reactor combined with high-resolution, low-energy electron-impact mass spectrometer under the following conditions: p =1-2 Torr, linear flow velocity v = 3.5-75 m s-1, T = 293 and 387 K, [ClONO2] = (0.5-25) × 1012 molecules cm-3. The salt was deposited as a film from nonsaturated aqueous solution on the sliding rod. The temporal dependences of the uptake coefficient and the partial uptake coefficients leading to a formation of the prime Cl2 and HOCl products were measured for different ClONO2 concentrations. These dependences are established to be described by γ = γ0 exp(-t/τ) + γs, γ0.s-1 = a0.S + b0.s[ClONO2]. In the framework of the proposed kinetic model, the data are explained and the main elementary kinetic parameters of the uptake are evaluated. The model is based on a combination of Langmuir adsorption, formation of surface complexes on initial active sites, Z ch, followed by their unimolecular decomposition. Decomposition is proposed to proceed concurrently in two channels, one of which is a released surface site that conserves the properties of the initial site. In the other channel, the initial Zch transforms into Zph followed by steady-state uptake and reproduction of final Zph. The model gives an analytical expression for experimental parameters γ0, γs, and τ in terms of elementary rate constants and the reactant volume concentration. The final objective of the proposed model is the extrapolation of γ0, γs, and r parameters to real tropospheric conditions.
- Zelenov,Aparina,Kashtanov,Shestakov,Gershenzon
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p. 6771 - 6780
(2008/10/09)
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- Temperature Dependence of the Rate Constant for the Reaction F( 2P) + Cl2 → FCl + Cl at T = 180-360 K
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The absolute rate constant for the reaction F(2P) with Cl 2 has been measured using the discharge flow kinetics technique coupled to mass spectrometric detection at T = 180-360 K and 1 Torr He nominal pressure. Experiments were performed at NASA Goddard Space Flight Center (GSFC) in Greenbelt, MD, and Laboratoire de Combustion et Systemes Reactifs-CNRS in Orleans, France. Results of k = (5.7 ± 0.8) × 10-11 and (6.2 ± 0.8) × 10-11 cm3 molecule-1 s-1 independent of temperature were obtained by each laboratory, respectively. When the results from both laboratories were combined into one data set, an average temperature independent value of k1 = (6.0 ± 1.1) × 10-11 cm3 molecule-1 s-1 was obtained. A very slight positive temperature dependence with k1(T) = (6.5 ± 1.5) × 10-11 exp{-(20 ± 60)/T} cm3 molecule-1 s-1 may also be derived from the combined data in the range T = 180-360 K.
- Nesbitt, Fred L.,Cody, Regina J.,Dalton, Douglas A.,Riffault, Veronique,Bedjanian, Yuri,Le Bras, Georges
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p. 1726 - 1730
(2007/10/03)
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- Synthese binaerer und ternaerer fluoride
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Die Druckfluorierung mit elementarem Fluor (p(F2) ~ 1-3E+3 bar) oder wasserfreier HF (im folgenden aHF= anhydrous HF) [p(HF) ~ 1-200 bar]) bzw. Mischungen von beiden ist eine Moeglichkeit bzw. Methode, thermisch empfindliche oder fluechtige binaere wie auch ternaere Fluoride in unterschiedlichen Oxidationsstufen insbesondere auch in einkristalliner Form darzustellen.
- Mueller, B. G.
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- Reaction of CF3OCl with Lewis Acids and with Br2 and I2
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The reactions of CF3OCl with SbX5 (X = F, Cl) and AsF5 at 195 K yield the adducts CF3OCl*SbX5 and CF3OCl*AsF5 respectively.At 213 K CF3OCl*SbCl5 forms SbCl4F, Cl2 and OCF2, while compounds CF3OCl*MF5 (M = As, Sb) slowly decompose giving ClF, OCF2 and mixed M(V) halides.The formation of IF5, OCF2 and Cl2 in the oxidative fluorination of I2 with CF3OCl at 293 K is described.Br2 reacts with CF3OCl to give BrF3 under similar conditions. - Keywords: Trifluoromethyl Hypochlorite Antimony Pentachloride and Pentafluoride Adduct; Trifluoromethyl Hypochlorite Arsene Pentafluoride Adduct; Vibrational Spectra; NMR Spectra
- Minkwitz, Rolf,Konikowski, Detlef
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p. 1277 - 1280
(2007/10/03)
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- Isolation of H2S...ClF in a pre-reactive mixture of H2S and ClF expandedin a coaxial jet and characterization by rotational spectroscopy
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The reaction between H2S and ClF was precluded and H2S...ClF isolated bya coaxial supersonic expansion of the gaseous components into the Fabry -Perot cavity of a pulsed-nozzle, Fourier-transform microwave spectrometer. The ground-state rotational spectra of seven isotopomers of H2S...ClF were analysed and gave in each case the spectroscopic constants 1/2(B(0)+C(0)), D(J), χ(aa) (Cl) and M(bb) (Cl). Interpretation of these constants revealed the complex to have a geometry of C(s) symmetry with the S...Cl-F nuclei collinear in the order shown, with the angle 180°-φ=84.2(4)° between the C(2) axis of H2S and the S...Cl-F axis, and with r(S...Cl)=2.857(3)?.
- Bloemink, H. I.,Hinds, K.,Holloway, J. H.,Legon, A. C.
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p. 113 - 120
(2008/10/08)
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- Eine gaskinetische Studie zur Reaktion von HOCl mit F-, Cl- und H-Atomen bei Raumtemperatur
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Chemical Kinetics / Elementary Reactions / Fluorescence / Mass Spectrometry / Radicals.The reactions of HOCl with F-, Cl- and H-atoms were investigated at room temperature in a discharge flow system equipped with an OH-resonance fluorescence cell and a mass spectrometric detector.All kinetic studies were carried out under pseudo first order conditions with HOCl being the minority component.Branching ratios for individual processes were obtained by following simultaneously the rates of HOCl consumption and product formation.The following rate constants (in units cm3 molecule-1 s-1) were determined: .Calibration for using reaction (1) for gas titration is discussed.The data are evaluated to yield ΔHf = -79.7 kJ mol-1 for the heat of HOCl formation.
- Vogt, R.,Schindler, R.N.
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p. 819 - 829
(2007/10/02)
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- The reactions of positive and negative halogen ions with Cl2 and Br2
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A selected ion flow tube study has been carried out at 300 K of the reactions of some atomic and molecular positive and negative halogen ions with Cl2 and Br2 from which the rate coefficients k and ion product distributions have been determined.For the energetic F+ ion reactions, dissociative charge transfer is the dominant process, while for the Cl+ ions, only nondissociative charge transfer occurs.For the less energetic Br+ and I+ reactions, dihalogen molecular ions are important products.All these positive ion reactions proceed quite efficiently, i.e., the k are appreciable fractions of kc, their respective collisional rate coefficients, except for the reactions of Cl2 with the lower energy ions of the spin-orbit triplet of I+, i.e., I+(3P1,0), for which k ca. 0.07kc, this being due to the endothermicities of the reactions.The molecular ion Cl2+ undergoes rapid nondissociative charge transfer with Br2, a process which is, of course, endothermic for the reaction of Br2+ with Cl2 and so no reaction is observed.The less-energetic atomic negative ion reactions proceed-via atom exchange-in which the atomic negative ion of the reactant molecular species and a dihalogen molecule are produced.For those reactions that are exothermic, the k are, within error, equal to (2/3)kc, implying that they proceed via complexes which separate statistically back to reactants (1/3) and forward to products (2/3).Both the Br- + Cl2 and Cl- + Br2 reactions are somewhat less efficient (i.e., k c), a result of the slight endothermicities of the reactions.Of the molecular negative ion reactions, electron transfer is the major process in the Cl2- reaction with Br2, whereas the reaction of Br2- with Cl2 proceeds relatively slowly producing the triatomic ion BrCl2-.
- Spanel, P.,Tichy, M.,Smith, D.
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p. 8660 - 8666
(2007/10/02)
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- Preparation of the nitryl salts ON(Cl)F+AsF6-, ON(CF3)F+AsF6-, and HON(CH2)CF3+SbF6- and crystal structure of HON(CH2)CF3+AsF6-
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The ON(Cl)F+AsF6- and ON(CF3)F+AsF6- salts are prepared by oxidative fluorination of ONCl and ONCF3 with N2F+AsF6-. Methylation of ONCF3 with CH3F and AsF5 gives ON(CH3)CF3+AsF6-, which in the solid state exists as the enol tautomer hydroxylimmonium salt HON(CH2)CF3+AsF6-, triclinic, of space group P1 with a = 5.063 (1) ?, b = 7.757 (3) ?, c = 10.429 (2) ?, α = 86.75 (2)°, β = 89.34 (2)°, and γ = 74.12 (2)°. The framework of the cation is planar, with C-N bond lengths of 147.7 (5) and 127.3 (5) pm and an N-O distance of 137.2(4) pm. The cation and anion have a short H?F contact of 166 (6) pm. An alternative method for the preparation of ONF2+MF6- (M = As, Sb) was found involving the oxidative fluorination of ONF with XeF+MF6-.
- Minkwitz, Rolf,Bernstein, Dirk,Preut, Hans,Sartori, Peter
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p. 2157 - 2161
(2008/10/08)
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- Fluoride-promoted competitive reactions of cyanogen fluoride, perfluoromethanimine, and pentafluoro-2-azapropene
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Competitive reactions of cyanogen fluoride (FC≡N), perfluoromethanimine (CF2=NF), and pentafluoro-2-azapropene (CF3N=CF2) were performed by combining pairs of the substrates over KF or CsF. These reactions establish the order of reactivity with fluoride ion as CF2=NF > CF3N=CF2 ? F - C≡N. Subsequent reactions of the addition products with fluoride ion, CIF, and Br2/CsF are discussed. Seven new compounds, including a novel diaziridine, were characterized by IR, NMR, MS, and physical properties.
- Bauknight Jr., Charles W.,DesMarteau, Darryl D.
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p. 728 - 733
(2007/10/02)
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- Disproportionation of chlorine in hydrogen fluoride and related media
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Chlorine can be made to disproportionate to chlorine monofluoride and chloride, taking advantage of Le Chatelier's principle in several different ways.It will disproportionate to form insoluble silver chloride and chlorine monofluoride when silver fluoride is present.It will disproportionate in a melt of alkali metal fluorides to form alkali metal chlorides and chlorine monofluoride.The alkali metal chlorides will react with hydrogen fluoride to regenerate the metal fluorides and hydrogen chloride.Chlorine will also disproportionate in hydrogen fluoride containing antimony pentafluoride to yield antimony pentafluoride adducts of chlorine monofluoride and of hydrogen chloride.These adducts are readily decomposed to yield the disproportionation products and the original antimony pentafluoride.Key words: hydrogen fluoride, disproportionation, chlorine, waterlike, solvent system
- Gambardella, Mario,Kongpricha, Santad,Pitts, James J.,Jache, Albert W.
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p. 1828 - 1831
(2007/10/02)
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- Kinetics and Mechanism of X + ClNO -> XCl + NO (X = Cl, F, Br, OH, O, N) from 220 to 450 K. Correlation of Reactivity and Activation Energy with Electron Affinity of X
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The rate constants for a series of radical reactions with ClNO, X + ClNO -> products where X = Cl, F, Br, OH, O, N, have been measured as a function of temperature in discharge flow systems at pressures between 1 and 2 Torr of helium buffer gas.Radicals were detected by resonance fluorescence (X = Cl, Br, OH, O), laser magnetic resonance (X = OH), and chemical conversion/resonance fluorescence (X = F, N).The rate constants, with units of cm3 molecule-1 s-1 and to 95 percent confidence level, are for Cl + ClNO -> Cl2 + NO, e(-128+/-46)/T; for F + ClNO -> FCl + NO, e(-28+/-84)/T; for Br + ClNO -> BrCl + NO, e(-52+/-43)/T; for OH + ClNO -> ClOH + NO, e(-1130+/-170)/T; for OH + ClNO -> HONO + Cl, e(240+/-130)/T; for O + ClNO -> ClO + NO, e(-1520+/-36)/T; and for N + ClNO -> NCl + NO, e(-2250+/-90)/T.Both the reaction activation energies and the logarithms of the room temperature rate constants are found to correlate strongly with the affinity of the radical in such a way that high electron affinity leads to enhanced reactivity.The reactivity trend is rationalized by a frontier orbital interaction dominated by the ease with which electron transfer from the CINO molecule to the X radical can occur to stabilize a polar transition state, a mechanism shown to be widely prevalent in radical-molecule systems.The propensity for this type of interaction is determined by the energy required for electron transfer which, in this case, is given by IPCINO - EAX, where IP refers to ionization potemtial and EA to electron affinity.In addition, the A factors for the X/CINO reactions are found to increase as the electron affinity of the radical increases, indicating that the tightness of the reansition state is directly related to the height of the activation barrier.
- Abbatt, J. P. D.,Toohey, D. W.,Fenter, F. F.,Stevens, P. S.,Brune, Wm. H.,Anderson, J. G.
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p. 1022 - 1029
(2007/10/02)
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- Reactions of chlorine fluorides and oxyfluorides with the nitrate anion and alkali-metal fluoride catalyzed decomposition of ClF5
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The binary chlorine fluorides ClF5, ClF3, and ClF, when used in an excess, all undergo facile fluorine-oxygen exchange reactions with the nitrate anion, forming FClO2, unstable FClO, and ClONO2, respectively, as the primary products. Whereas FClO3 does not react with LiNO3 at temperatures as high as 75°C, FClO2 readily reacts with either LiNO3 or N2O5 to give ClONO2 and O2 in high yield, probably via the formation of an unstable O2ClONO2 intermediate. With an excess of ClF, chlorine nitrate undergoes a slow reaction to give FNO2 and Cl2O as the primary products, followed by Cl2O reacting with ClF to give Cl2, ClF, and FClO2. The alkali-metal fluorides CsF, RbF, and KF catalyze the decomposition of ClF5 to ClF3 and F2, which can result in the generation of substantial F2 pressures at temperatures as low as 25°C.
- Christe, Karl O.,Wilson, William W.,Wilson, Richard D.
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p. 675 - 677
(2008/10/08)
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- Synthesis and characterization of NF4CrF6 and reaction chemistry of CrF5
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NF4CrF6, a new stable NF4+ salt containing an energetic counterion, was prepared by treatment of CrF5 with an excess of NF4HF2 in HF solution. The composition and ionic nature of NF4CrF6 was established by elemental analysis, vibrational and 19F NMR spectroscopy, and its X-ray powder pattern. Reactions of CrF5 with H2O in HF, ClF3, FNO, Cl2, CFCl3, and KrF2 were studied to determine its acidity and oxidizing power. With FNO, a stable 1:1 adduct is formed, which on the basis of its vibrational spectra has the ionic structure NO+CrF6-. The reaction of NOCrF6 with NO produced (NO+)2CrF62-, which by controlled pyrolysis was converted to NO+CrF5-. With stoichiometric amounts of H2O in HF, CrF5 did not form a stable OH3+CrF6- salt but the reaction resulted in hydrolysis to CrF3O. The influence of the strong Lewis acids AsF5 and SbF5 on the oxidizing power of CrF5 was also investigated. On the basis of the fact that CrF5-SbF5 mixtures can oxidize O2 (IP = 12.06 eV) but not NF3 (IP = 13.00 eV), the following qualitative oxidizer strength scale is proposed: KrF+ > PtF6 > SbF5 + F2 + activation energy > CrF5-SbF5. The results of a normal-coordinate analysis of CrF6- and CrF62- show the expected decrease in force constants with increasing negative charge.
- Bougon, Roland,Wilson, William W.,Christe, Karl O.
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p. 2286 - 2292
(2008/10/08)
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- Ion-molecule reactions of CL2 with CL- and F-
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Using the flowing afterglow technique, we have examined the process Cl2 + Cl- ->Cl3- in helium buffer gas.The system was studied over a range of helium pressures and the dependence of the apparent two-body rate upon the buffer gas concentration gives a three-body rate constant for the process: k = 0.9*10-29 cm6 molecule-2s-1.In addition, we looked at the analogous process involoving a fluoride ion.There is no evidence for formation of the trihalide Cl2F- under our experimental conditions.A charge exchange process between Cl2 and F- to produce Cl- and neutral ClF does occur, however.This rate is independent of the pressure of the helium buffer gas: k = 8.8*10-10 cm3 molecule-1 s-1.
- Babcock, Lucia M.,Streit, Gerald E.
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p. 2407 - 2411
(2007/10/02)
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- Syntheses and properties of FOIF4O, ClOIF4O, HOIF4O, and tetrafluoroperiodates
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Mixtures of cis- and trans-CsIF4O2 were prepared by the interaction of CsIO4 with either anhydrous HF, BrF5, ClF3, ClF5, or F2. The vibrational spectra of these mixtures were recorded, and partial assignments are given for cis- and trans-IF4O2-. The assignments for trans-IF4O2- were supported by a normal-coordinate analysis. The CsIF4O2 salt dissolves in CH3CN with the formation of IF4O2- anions but undergoes solvolysis in anhydrous HF with formation of HOIF4O. An improved synthesis of HOIF4O from CsIF4O2 and BiF5 in anhydrous HF is reported, and its Raman and 19F NMR spectra were recorded. The interaction of CsIF4O2 with NF4SbF6 in anhydrous HF results in solutions containing NF4+, HF2-, and HOIF4O. When standing or when pumped to dryness, these mixtures decompose to yield NF3 and the new compound FOIF4O in high yield. The latter compound, the first known example of an iodine hypofluorite, was thoroughly characterized and shown by vibrational and NMR spectroscopy to be a mixture of the cis and trans isomers. For comparison, the vibrational spectra of IF5O have also been recorded. The reaction of CsIF4O2 with ClOSO2F was shown to yield the novel compound ClOIF4O. The fluorination reactions of CsIO4, CsIF4O2, IF5O, and HOIF4O with elementary fluorine were also studied.
- Christe, Karl O.,Wilson, Richard D.,Schack, Carl J.
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p. 2104 - 2114
(2008/10/08)
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- Millimetr wave measurements of the rotational spectra of ClF, BrF, BrCl, ICl, and IBr
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The rotational spectra of all twelve stable isotopic species of ClF, BrF, BrCl, ICl, and IBr were abserved and measured in the millimeter wave region by means of a sensitive microwave spectrometer.Transitions were detected over a wide range of frequencies for molecules in both the ground vibrational state and several excites states.The rotational spectrum of each molecule was split by the nuclear quadrupole interaction.Altogether, 250 new lines were measured.These correspond to 136 purw rotational transitions.Values of the Dunham coefficients Y01, Y11, Y21, Y31, Y02, Y12, and Y03 were obtained from a computer analysis of the measured frequencies.From these coefficients a number of equilibrium constants were derived to significantly greater accuracy than in previous work.In particular, the equilibrium distance, re, was found to two or three more significant figures.
- Willis, Robert E.,Clark, William W.
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p. 4946 - 4950
(2007/10/02)
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