OsO₃F₂ and OsO₂F₄, Preparation and Crystal Structures

Abstract

A new method for preparing Os03Fz is presented. Its crystal structure reveals a polymeric chain structure with distorted octahedral geometry for the Os03F3 units and symmetrical, non-linear fluorine bridges. The Os0,F3 unit has a facial geometry. This structure is not in accord with predictions on the molecular structure of Os03F,. OsOzF,, obtained from KrFz and Os04, crystallizes in the space group forming a sixfold helical chain arrangement of nearly octahedral Os02F, molecules. Oxygen or fluorine atoms are partially disordered. The cis orientation of the two oxygen atoms is established by means of NMR, vibrational spectroscopy, and X-ray data.

Lewis Acid Behavior of ReO2F3: Synthesis of (ReO2F3)∞, ReO2F4-, Re2O4F7-, Re3O6F10-, and ReO2F3(CH3CN) and Study by NMR Spectroscopy, Raman Spectroscopy, and Density Functional Theory Calculations; and X-ray Structures of [Li][ReO2F4], [K][Re2O4F7Casteel1, Dixon2, LeBlond3 et al. 1999Inorg. Chem.3315710View full textAdd to dashboardCite

“…The Re−F c,c and Re−F c,t bond distances of all three anions and of polymeric ReO 2 F 3 are generally in good agreement with the terminal Re−F bond distances in ReO 3 F (1.859(8) Å), ReOF 6 - (ax, 1.894(11)−1.927(10); eq, 1.862(2)−1.917(7) Å), ReOF 5 (1.810(7) Å), ReO 2 F 3 (calculated: ax, 1.876; eq, 1.894 Å), (ReOF 4 ·SbF 5 ) 2 (1.841(15) Å), and ReOF 4 (1.86(4) Å), except in ReO 2 F 4 - where the Re−F c,t bond distance is in better agreement with the Re−F b bond distances in ReOF 4 (2.14(4) Å; range, 1.99(4)−2.28(4) Å) 15 and in Re 2 O 2 F 9 + (2.060(4) Å) TcO 2 F 4 - , the [OsO 3 F 3 ], [TcO 2 F 4 ], and [MoOF 5 ] units of the infinite chain polymers OsO 3 F 2 , TcO 2 F 3 , and MoOF 4 , the [TcOF 5 ] unit of trimeric TcOF 4 , and the [ cis -OsO 2 F 4 ] unit of Os 2 O 4 F 7 + . The difference has been attributed to the trans influence of the M−O double bonds of the d 0 metal, for which there are significant p π → d π interactions. ,, As a consequence, the M−F c,t bond lengths resemble those of M−F b bonds.…”

The First Phosphates of Heptavalent Rhenium

“…The repulsion between the cis positioned short bonds Re=O t is expected to be strong (VSEPR model) and is at least partially mitigated by expansion of the angle ∠(O t ,Re, O t ) from 90° to about 101.6°. These bond lengths and angles are in good agreement with those of other M O 2 3+ ions in Re 2 O 7 ,27 ReO 2 X 3 , ( X = Cl, F),28,29 TcO 2 F 3 ,30,31 OsO 2 F 3 ,32 as well as MoO 2 (SO 4 ) 24. The preference for the cis conformation can be understood in terms of the spatial arrangement required for p π → d π bonding between the strongly π‐donating oxygen atoms to the t 2g orbitals of the metal.…”

Difluorochloronium(III) Fluoridometallates – from Molecular Building Blocks to (Helical) Chains

“…The products from reactions of ClF 3 with metals, such as Mo, W, U, and metal oxides, such as UO 2 , ReO 3 , OsO 4 , are usually fluorides (MF 6 , M = Mo, W, U) and oxyfluorides (ReOF 5 , OsO 3 F 2 ), respectively, in high or highest oxidation states. [5][6][7][8] If ClF 3 is used in excess and reacted with a fluoride that has an appreciable fluoride ion affinity, such as AsF 5 or SbF 5 , a difluorochloronium(III) compound is formed. [9,10] With weaker Lewis acids, such as BF 3 and PF 5 , thermally unstable ClF 2 + salts, are formed.…”

“…The products from reactions of ClF 3 with metals, such as Mo, W, U, and metal oxides, such as UO 2 , ReO 3 , OsO 4 , are usually fluorides ( M F 6 , M = Mo, W, U) and oxyfluorides (ReOF 5 , OsO 3 F 2 ), respectively, in high or highest oxidation states. [ 5–8 ]…”