The OsO4F-, OsO4F22-, 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]

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 th e 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 th e Tractions of OsO3F2 With a stoichiometric amount of [N(CH3)(4)][F] in CH3 CN solvent and with excess NOF, respectively. The OsO4F-anion was fully str ucturally 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) Angstrom, b = 11.401(2) Angstrom, c = 10.925(2) Angstrom, V = 87 4.1(3) Angstrom(3), Z = 4, and R = 0.0282 at -50 degrees C. The cis-OsO4F22 - anion was characterized in the solid state by vibrational spectroscopy, a nd previous claims regarding the cis-OsO4F22- anion are shown to be erroneo us. The fac-OsO3F3- anion was fully structurally characterized in CH3CN sol ution by F-19 NMR spectroscopy and in the solid state by vibrational spectr oscopy of its N(CH3)(4+) and NO+ salts and by a single-crystal X-ray diffra ction study of [N(CH3)(4)][OsO3F3]: C2/c, a = 16.347(4) Angstrom, b = 13.47 5(3) Angstrom, c = 11.436(3) Angstrom, beta = 134.128(4)degrees V = 1808.1( 7) Angstrom(3), Z = 8, and R = 0.0614 at -117 DC. The geometrical parameter s and vibrational frequencies of OsO4F-, Cis-OsO4F22-, monomeric OsO3F2, an d fac-OsO3F3- and the fluoride affinities of OsO4 and monomeric OsO3F2 were calculated using density functional theory methods.