13774-85-1Relevant academic research and scientific papers
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 (2010/07/04)
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.
Synthesis and X-ray crystal structure of (OsO3F 2)2·2XeOF4 and the raman spectra of (OsO3F2)∞, (OsO3F 2)2, and (OsO3F2) 2·2XeOF4
Hughes, Michael J.,Mercier, Helene P.A.,Schrobilgen, Gary J.
, p. 4478 - 4490 (2009/09/24)
The adduct, (OsO3F2).2XeOF4, was synthesized by dissolution of the infinite chain polymer, (OsO3F 2), in XeOF4 solvent at room temperature followed by removal of excess XeOF4under dynamic vacuum at 0 °C. Continued pumping at 0°C resulted in removal of associated XeOF4, yielding (Os0 3F2)2, a new low-temperature phase of OsO3F2. Upon standing at 25 °C for 1/2 h, (Oso3F2)2 underwent a phase transition to the known monoclinic phase, (OsO 3F2). The title compounds, (OsO3F 2)∞ (OsO3F2)2, and (OsO 3F2)2.2XeOF4 have been characterized by low-temperature (-150 °C) Raman spectroscopy. Crystallization of (OsO3F2)2.2XeOF4 from XeOF 4 solution at O °C yielded crystals suitable for X-ray structure determination. The structural unit contains the (OsO3F 2)2 dimer in which the OsO3F3 units are joined by two Os-F-Os bridges having fluorine bridge atoms that are equidistant from the osmium centers (2.117(5) and 2.107(4) A). The dimer coordinates to two XeOF4molecules through OsF... Xe bridges in which the Xe... F distances (2.757(5) A) are significantly less than the sum of the Xe and F van der Waals radii (3.63 A). The (OsO3F2) 2 dimer has Ci symmetry in which each pseudo-octahedral OsO3F3 unit has a facial arrangement of oxygen ligands with XeOF4 molecules that are only slightly distorted from their gasphase C4v, symmetry. Quantum-chemical calculations using SVWN and B3LYP methods were employed to calculate the gas-phase geometries, natural bond orbital analyses, and vibrational frequencies of (OsO3F 2)2, (OsO3F2)2.2XeOF 4, XeOF4, OsO2F4, and (w-FOs0 3F2)2OsO3F~ to aid in the assignment of the experimental vibrational frequencies of (OsO3F 2)2, (OsO3F2)2.2XeOF 4, and (OsO3F2)∞ The vibrational modes of the low-temperature polymeric phase, (OsO3F2)∞ have been assigned by comparison with the calculated frequencies of (w-FOsO 3F2)2OsO3F-, providing more complete and reliable assignments than were previously available.
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.
Preparation of O2XeF2-x(OTeF5)x, OXeF4-y(OTeF5)y, and XeF4-y(OTeF5)y (x = 0-2, y = 0-4) and study by 129Xe and 19F NMR and Raman spectroscopy: The oxygen primary isotopic effect in the 129Xe NMR spectra of XeO2F2 and XeOF4
Schumacher, Gerhard A.,Schrobilgen, Gary J.
, p. 2923 - 2929 (2008/10/08)
A series of mixed fluoro/pentafluroorthotellurate (OTeF5) derivatives of the xenon(VI) oxyfluorides XeOF4 and XeO2F2, as well as those of XeF4, have been prepared and studied by 19F and 129Xe NMR spectroscopy. The compound O2Xe(OTeF5)2 has been prepared and isolated for the first time and, along with the previously reported Xe(OTeF5)4 and XeO(OTeF5)4 derivatives, has been characterized by low-temperature Raman spectroscopy. An oxygen-17 NMR study of the 17O/ 18O-enriched oxyfluorides XeO2F2 and XeOF4 and their 18O/16O primary isotopic shifts in the 129Xe NMR spectra are also reported.
Chemical Application of 99Tc NMR Spectroscopy: Preparation of Novel Tc(VII) Species and Their Characterization by Multinuclear NMR Spectroscopy
Franklin, Kenneth J.,Lock, Colin J. L.,Sayer, Brian G.,Schrobilgen, Gary J.
, p. 5303 - 5306 (2007/10/02)
The 99Tc NMR parameters of a number of Tc(VII) and one Tc(V) species have been determined.The anion TcO4- (Ξ = 22.508311 MHz in H2O) was chosen as the standard for 99Tc NMR spectroscopy.A 99Tc-17O coupling constant of 131.4 Hz was obtained from a 17O- and 18O-enriched sample of TcO4- whose 99Tc spectrum also showed an isotopic shift of 0.22 ppm/mass number arising from a statistical distribution of 16O/17O/18O isotopic isomers.Technetium-99 and proton NMR provided definitive proof for the existence of the stereochemically nonrigid TcH92- anion.Both TcO3F and the novel TcO3+ cation were synthesized and characterized by 99Tc, 17O, and 19F NMR spectroscopy.Preliminary results on two new technetium(VII) oxyfluorides tentatively identified as F2O2TcOTcO2F2 and TcO2F3 are also reported.The diamagnetic d2 anion, TcO2(CN)43-, represents the most deshielded 99Tc environment encountered in the present study.
Complexes of xenon oxide tetrafluoride
Selig, Henry
, p. 183 - 186 (2008/10/08)
Xenon oxide tetrafluoride bears a strong resemblance to the halogen fluorides both in physical properties and chemical behavior. A number of physical properties of XeOF4 have been measured. Xenon oxide tetrafluoride is a clear, colorless liquid freezing at -46.2°. Its electrical conductivity at 24° is 1.03 × 10-5 ohm-1 cm.-1 and its dielectric constant is 24.6 at 24°. It is miscible with anhydrous HF, but its conductivity is not enhanced in such a solution. The addition of CsF or RbF to XeOF4 increases its conductivity markedly. Xenon oxide tetrafluoride forms a series of addition compounds with the heavier alkali fluorides. The following complexes have been isolated: CsF·XeOF4, 3RbF-2XeOF4 and 3KF·-XeOF4. No reaction occurs with NaF. Thermogravimetric studies show that a number of intermediates are formed before final decomposition to the alkali fluorides. Xenon oxide tetrafluoride reacts with SbF5 to form a complex of composition XeOF4· 2SbF5. A reaction also occurs with AsF5 at -78°, but the complex is unstable at room temperature.
