13693-09-9Relevant academic research and scientific papers
Synthesis and crystal structure of (Xe2F11+)2NiF6 2-
Jesih, Adolf,Lutar, Karel,Leban, Ivan,Z?emva, Boris
, p. 2911 - 2914 (1989)
(Xe2F11+)2NiF6 2- has been prepared by the reaction between nickel difluoride, krypton difluoride, and xenon hexafluoride in anhydrous hydrogen fluoride. (Xe2F11+)2NiF6 2- crystallizes in the monoclinic space group I2/a with a = 17.477 (5) ?, b = 5.384 (6) ?, c = 21.300 (8) ?, β = 102.83 (3)°, V = 1954.2 ?3, Z = 4, and dc = 3.792 g cm-3. A structure determination using three-dimensional Mo Kα X-ray data resulted in conventional R and Rw factors of 0.070 and 0.094, respectively, for 1355 unique reflections for which I > 3σ(I). The anion NiF62- is essentially octahedral; Ni-F distances range from 1.77 (1) to 1.79 (1) ?. The Xe2Fu+ ion consists of two XeF5 groups bridged by an additional common fluorine atom. The bridge bond lengths are 2.35 (1) and 2.21 (1) ? with a bridge angle of 140.3 (6)°. (Xe2F11+)2NiF6 2- represents the first known crystal structure of a compound with two Xe2F11+ cations.
The xenon-fluorine system
Weinstock, Bernard,Weaver, E. Eugene,Knop, Charles P.
, p. 2189 - 2203 (1966)
Equilibrium constants have been obtained in the Xe-F2 system in the temperature range 250-500°. The data show that only three binary fluorides, XeF2, XeF4, and XeF6, are present. There is no evidence for the existence of XeF8 at 250° and up to 500 atm of F2. A preparation of pure XeF6 is described. A molecular weight determination, some infrared measurements, and vapor pressure data obtained with this sample are reported. Values for the thermodynamic properties of formation of XeF2, XeF4, and XeF6 are derived from the equilibrium constant data. The average value of the two missing vibrational modes of XeF4 is evaluated to be 246 ± 10 cm-1 from an analysis of the equilibrium constant and molecular data. Thermodynamic properties of XeF2 and XeF4 are calculated from molecular data. The value of S° for XeF4 at 25° is 75.6 cal mole-1 deg-1, in agreement with a value of 75.3 cal mole-1 deg-1 calculated from calorimetric data and the heat of sublimation. A number of molecular models for XeF6 are examined in terms of their consistency with the equilibrium constant data. A definite choice among the various models is not possible, but the analysis favors a low symmetry for XeF6. Values of S° for XeF6 at 25° are derived for each model and may be useful to help determine the symmetry of XeF6 when calorimetric data become available. The average bond energy of XeF2 is 31.0 kcal and that of XeF4 is 30.9 kcal. For XeF6 the average bond energy is 29.7 kcal, so that the average energy for forming the last two bonds in XeF6 is 27.3 kcal.
Syntheses and Structures of F6XeNCCH3 and F6Xe(NCCH3)2
Matsumoto, Kazuhiko,Haner, Jamie,Mercier, Hélène P. A.,Schrobilgen, Gary J.
, p. 14169 - 14173 (2015)
Acetonitrile and the potent oxidative fluorinating agent XeF6 react at -40 C in Freon-114 to form the highly energetic, shock-sensitive compounds F6XeNCCH3 (1) and F6Xe(NCCH3)2CH3CN (2CH3CN). Their low-temperature single-crystal X-ray structures show that the adducted XeF6 molecules of these compounds are the most isolated XeF6 moieties thus far encountered in the solid state and also provide the first examples of XeVI-N bonds. The geometry of the XeF6 moiety in 1 is nearly identical to the calculated distorted octahedral (C3v) geometry of gas-phase XeF6. The C2v geometry of the XeF6 moiety in 2 resembles the transition state proposed to account for the fluxionality of gas-phase XeF6. The energy-minimized gas-phase geometries and vibrational frequencies were calculated for 1 and 2, and their respective binding energies with CH3CN were determined. The Raman spectra of 1 and 2CH3CN were assigned by comparison with their calculated vibrational frequencies and intensities.
Stable Chloro- and Bromoxenate Cage Anions; [X3(XeO3)3]3- and [X4(XeO3)4]4- (X = Cl or Br)
Goettel, James T.,Haensch, Veit G.,Schrobilgen, Gary J.
, p. 8725 - 8733 (2017)
The number of isolable compounds which contain different noble-gas-element bonds is limited for xenon and even more so for krypton. Examples of Xe-Cl bonds are rare, and prior to this work, no Xe-Br bonded compound had been isolated in macroscopic quantities. The syntheses, isolation, and characterization of the first compounds to contain Xe-Br bonds and their chlorine analogues are described in the present work. The reactions of XeO3 with [N(CH3)4]Br and [N(C2H5)4]Br have provided two bromoxenate salts, [N(C2H5)4]3[Br3(XeO3)3] and [N(CH3)4]4[Br4(XeO3)4], in which the cage anions have Xe-Br bond lengths that range from 3.0838(3) to 3.3181(8) ?. The isostructural chloroxenate anions (Xe-Cl bond lengths, 2.9316(2) to 3.101(4) ?) were synthesized by analogy with their bromine analogues. The bromo- and chloroxenate salts are stable in the atmosphere at room temperature and were characterized in the solid state by Raman spectroscopy and low-temperature single-crystal X-ray diffraction, and in the gas phase by quantum-chemical calculations. They are the only known examples of cage anions that contain a noble-gas element. The Xe-Br and Xe-Cl bonds are very weakly covalent and can be viewed as σ-hole interactions, similar to those encountered in halogen bonding. However, the halogen atoms in these cases are valence electron lone pair donors, and the σ?Xe-O orbitals are lone pair acceptors.
Syntheses, Raman Spectra, and X-ray crystal structures of [XeF 5][μ-F(OsO3F2)2] and [M][OsO 3F3] (M = XeF5+, Xe 2F11+)
Hughes, Michael J.,Mercier, Helene P. A.,Schrobilgen, Gary J.
, p. 3501 - 3515 (2010)
Stoichiometric amounts of XeF6 and (OsO3F 2)∞ react at 25-50 °C to form salts of the known XeF5+ and Xe2F11+ cations, namely, [XeF5][μ-F(OsO3F2) 2], [XeF5][OsO3F3], and [Xe 2F11][OsO3F3]. Although XeF 6 is oxophllic toward a number of transition metal and main-group oxides and oxide fluorides, fluoride/oxide metathesis was not observed. The series provides the first examples of noble-gas cations that are stabilized by metal oxide fluoride anions and the first example of a μ-F(OsO 3F2)2 salt. Both [XeF5][μ- F(OsO3F2)2] and [Xe2F 11][OsO3F3] are orange solids at room temperature. The [XeF5][OsO3F3] salt is an orange liquid at room temperature that solidifies at 5-0°C. When the salts are heated at 50 °C under 1 atm of N2 for more than 2 h, significant XeF6 loss occurs. The X-ray crystal structures (-173 °C) show that the salts exist as discrete ion pairs and that the osmium coordination spheres in OsO3F3- and μ-F(OsO 3F2)2- are pseudo-octahedral OsO 3F3-units having facial arrangements of oxygen and fluorine atoms. The μ-F(OsO3F2)2- anion Is comprised of two symmetry-related OsO3F2-groups that are fluorine-bridged to one another. Ion pairing results from secondary bonding interactions between the fluorine/oxygen atoms of the anions and the xenon atom of the cation, with the Xe...F/O contacts occurring opposite the axial fluorine and from beneath the equatorial XeF4-planes of the XeF 5 and Xe2F11 cations so as to avoid the free valence electron lone pairs of the xenon atoms. The xenon atoms of [XeF 5][μ-F(OsO3F2)2] and [Xe 2F11][OsO3F3] are nine-coordinate and the xenon atom of [XeF5][OsO3F3] is eight-coordinate. Quantum-chemical calculations at SVWN and B3LYP levels of theory were used to obtain the gas-phase geometries, vibrational frequencies, and NBO bond orders, valencies, and NPA charges of the ion pairs, [Xe 2F11][OsO3F3], [XeF 5][OsO3F3], and [XeF5][μ- F(OsO3F2)2,] as well as those of the free ions, Xe2F11+, XeF5-, OsO 3F3-, and μ-F(OsO3F 2)2-, The Raman spectra (-150 °C) of the salts have been assigned based on the ion pairs observed in the crystal structures and the calculated vibrational frequencies and intensities of the gas-phase ion pairs.
New syntheses and properties of XeO2F2, Cs+XeO2F3-, and NO2+[XeO2F3·nXeO 2F2]-
Christe, Karl O.,Wilson, William W.
, p. 3763 - 3768 (2008/10/08)
Alkali-metal nitrates and N2O5 are useful reagents for the stepwise replacement of two fluorine atoms by one oxygen atom in xenon fluorides or oxyfluorides. Thus, the reaction of an excess of XeF6 with CsNO3 yields XeOF4, FNO2, and CsXeF7 in high yield. With CsNO3 in excess, the primary products are CsXeOF5 and FNO2, and after longer reaction times some CsXeO2F3 is also formed. The reaction of CsNO3 with an excess of XeOF4 produces FNO2 and XeO2F2 in quantitative yield with a mixture of CsF and CsXeOF5 as the byproducts. Recrystallization of this CsF-CsXeOF5-XeO2F2 mixture from anhydrous HF provides a convenient synthesis for CsXeO2F3. The reaction of N2O5 with an excess of XeOF4 results in XeO2F2 and FNO2, thus providing a new safe synthesis for XeO2F2. Vibrational spectra of liquid, solid, and Ar-matrix-isolated XeO2F2 are reported. With FNO2, xenon dioxide difluoride forms an unstable NO2+[XeO2F3·nXeO 2F2]- adduct, which was characterized by Raman spectroscopy. The vibrational spectra of CsXeO2F3 were recorded and assigned. It is shown that the two oxygen atoms in XeO2F3- are cis and not trans to each other and that the Raman spectrum previously attributed to Cs+XeO2F3- is due to a Cs+[XeO2F3·nXeF2]- adduct.
