The Osmium(VIII) Oxofluoro Cations OsO₂F₃⁺ and F(cis-OsO₂F₃)₂⁺:  Syntheses, Characterization by ¹⁹F NMR Spectroscopy and Raman Spectroscopy, X-ray Crystal Structure of F(cis-OsO₂F₃)₂⁺Sb₂F₁₁^-, and Density Functional Theory Calculations of OsO₂F₃⁺, ReO₂F₃, and F(cis-OsO

Abstract

Osmium dioxide tetrafluoride, cis-OsO(2)F(4), reacts with the strong fluoride ion acceptors AsF(5) and SbF(5) in anhydrous HF and SbF(5) solutions to form orange salts. Raman spectra are consistent with the formation of the fluorine-bridged diosmium cation F(cis-OsO(2)F(3))(2)(+), as the AsF(6)(-) and Sb(2)F(11)(-) salts, respectively. The (19)F NMR spectra of the salts in HF solution are exchange-averaged singlets occurring at higher frequency than those of the fluorine environments of cis-OsO(2)F(4). The F(cis-OsO(2)F(3))(2)(+)Sb(2)F(11)(-) salt crystallizes in the orthorhombic space group Imma. At -107 degrees C, a = 12.838(3) Å, b = 10.667(2) Å, c = 11.323(2) Å, V = 1550.7(8) Å(3), and Z = 4. Refinement converged with R = 0.0469 [R(w) = 0.0500]. The crystal structure consists of discrete fluorine-bridged F(cis-OsO(2)F(3))(2)(+) and Sb(2)F(11)(-) ions in which the fluorine bridge of the F(cis-OsO(2)F(3))(2)(+) cation is trans to an oxygen atom (Os-O 1.676 Å) of each OsO(2)F(3) group. The angle at the bridge is 155.2(8) degrees with a bridging Os---F(b) distance of 2.086(3) Å. Two terminal fluorine atoms (Os-F 1.821 Å) are cis to the two oxygen atoms (Os-O 1.750 Å), and two terminal fluorine atoms of the OsO(2)F(3) group are trans to one another (1.813 Å). The OsO(2)F(3)(+) cation was characterized by (19)F NMR and by Raman spectroscopy in neat SbF(5) solution but was not isolable in the solid state. The NMR and Raman spectroscopic findings are consistent with a trigonal bipyramidal cation in which the oxygen atoms and a fluorine atom occupy the equatorial plane and two fluorine atoms are in axial positions. Density functional theory calculations show that the crystallographic structure of F(cis-OsO(2)F(3))(2)(+) is the energy-minimized structure and the energy-minimized structures of the OsO(2)F(3)(+) cation and ReO(2)F(3) are trigonal bipyramidal having C(2)(v)() point symmetry. Attempts to prepare the OsOF(5)(+) cation by oxidative fluorination of cis-OsO(2)F(4) with KrF(+)AsF(6)(-) in anhydrous HF proved unsuccessful.

Syntheses, Structures, and Bonding of NgF2⋅CrOF4, NgF2⋅2CrOF4(Ng=Kr, Xe), and (CrOF4)∞

“…Anhydrous HF must be handled by using appropriate protective gear with immediate access to proper treatment procedures [53] in the event of contact with the liquid, vapor,o ri ts solutions. Anhydrous HF must be handled by using appropriate protective gear with immediate access to proper treatment procedures [53] in the event of contact with the liquid, vapor,o ri ts solutions.…”

Thiazyl Trifluoride (NSF3) Adducts and Imidodifluorosulfate (F2OSN-) Derivatives of Hg(OTeF5)2

“…Manipulations involving air-sensitive materials were carried out under anhydrous conditions on glass and metal high-vacuum lines and inside an inert atmosphere drybox as previously described. 50 Preparative work was carried out in T-shaped reaction vessels constructed from 1/4-in. o.d.…”

“…wall thickness) of FEP (tetrafluoroethylene-hexafluoropropylene block copolymer) tubing. 50 The tubing was heat-sealed at one end, heat flared at the other end, and connected through a 45°SAE flare nut to the conical end of a Kel-F (chlorotrifluoroethylene polymer) valve to form a compression seal. Reaction vessels and sample tubes were rigorously dried under dynamic vacuum for at least 8 h prior to passivation with 1 atm of F 2 gas.…”

A Raman spectroscopic study of the XeOF4/XeF2 system and the X-ray crystal structure of α-XeOF4·XeF2

“…Manipulations involving air-sensitive materials were carried out under anhydrous conditions as previously described [47]. All preparative work was carried out in 1/4-in.…”