The OsO₄F^-, OsO₄F₂^2-, and OsO₃F₃^- Anions, Their Study by Vibrational and NMR Spectroscopy and Density Functional Theory Calculations, and the X-ray Crystal Structures of [N(CH₃)₄][OsO₄F] and [N(CH₃)₄][OsO₃F₃]

Abstract

The fluoride ion acceptor properties of OsO4 and OsO3F2 were investigated. The salts [N(CH3)4][OsO4F] and [N(CH3)4]2[OsO4F2] were prepared by the reactions of OsO4 with stoichiometric amounts of [N(CH3)4][F] in CH3CN solvent. The salts [N(CH3)4][OsO3F3] and [NO][OsO3F3] were prepared by the reactions of OsO3F2 with a stoichiometric amount of [N(CH3)4][F] in CH3CN solvent and with excess NOF, respectively. The OsO4F- anion was fully structurally characterized in the solid state by vibrational spectroscopy and by a single-crystal X-ray diffraction study of [N(CH3)4][OsO4F]: Abm2, a = 7.017(1) A, b = 11.401(2) A, c = 10.925(2) A, V = 874.1(3) A3, Z = 4, and R = 0.0282 at -50 degrees C. The cis-OsO4F2(2-) anion was characterized in the solid state by vibrational spectroscopy, and previous claims regarding the cis-OsO4F2(2-) anion are shown to be erroneous. The fac-OsO3F3- anion was fully structurally characterized in CH3CN solution by 19F NMR spectroscopy and in the solid state by vibrational spectroscopy of its N(CH3)4+ and NO+ salts and by a single-crystal X-ray diffraction study of [N(CH3)4][OsO3F3]: C2/c, a = 16.347(4) A, b = 13.475(3) A, c = 11.436(3) A, beta = 134.128(4) degrees, V = 1808.1(7) A3, Z = 8, and R = 0.0614 at -117 degrees C. The geometrical parameters and vibrational frequencies of OsO4F-, cis-OsO4F2(2-), monomeric OsO3F2, and fac-OsO3F3- and the fluoride affinities of OsO4 and monomeric OsO3F2 were calculated using density functional theory methods.

The solid-state 19F NMR spectrum of [N(CH3)4][IO2F2], a vibrational study of [N(CH3)4][IO3] and [N(CH3)4][IO3]·2H2O, and the X-ray crystal structures of [N(CH3)4][IO2F2] and [N(CH3)4][IO3]

“…2b). The N(CH 3 ) 4 + cation is essentially tetrahedral with the expected bond lengths[22].The I-O bond lengths in [N(CH 3 ) 4 ][IO 3 ] (1.8176(9) and 1.8072(14) Å ) are significantly longer than two of the I-O bond lengths of the corresponding dihydrate of [N(CH 3 ) 4 ] [IO 3 ]Á2H 2 O (1.773(9), 1.776(4), and 1.807(9) Å [11]). This corroborates vibrational spectroscopic evidence that hydrogen bonding in the dihydrate strengthens the I-O bonds.…”

Interactions between SF4 and Fluoride: A Crystallographic Study of Solvolysis Products of SF4·Nitrogen-Base Adducts by HF

“…Crystals were mounted at low temperature under a stream of dry cold nitrogen as previously described. 16 For wet samples, cut FEP tubes were manipulated in the cold trough, at temperatures just above the freezing point of the solvent. Solvents were removed using a combination of glass pipettes and capillary action of Kimwipes.…”

A new synthetic route to rhenium and iodine oxide fluoride anions: The reaction between oxoanions and sulfur tetrafluoride

“…After removal of the removal of most of the volatiles at -40 °C, crystals were selected at low temperature under a stream of dry cold nitrogen as previously described. [24] The crystals were centered on a Bruker SMART APEX II diffractometer, controlled by the APEX2…”