Osmium pentafluoride

Osmium pentafluoride
Identifiers
CAS Number	31576-40-6;
3D model (JSmol)	monomer: Interactive image; tetramer: Interactive image;
ChemSpider	103874289;
PubChem CID	15797581;
	InChI InChI=1S/5FH.Os/h5*1H;/q;;;;;+5/p-5 Key: RFWLPKSDISVSGM-UHFFFAOYSA-I;
	SMILES monomer: F[Os](F)(F)(F)F; tetramer: F[Os-]1(F)(F)(F)[F+][Os-](F)(F)(F)(F)[F+][Os-](F)(F)(F)(F)[F+][Os-](F)(F)(F)(F)[F+]1;
Properties
Chemical formula	F5Os
Molar mass	285.22 g·mol−1
Appearance	blue-green solid
Melting point	70 °C (158 °F; 343 K)
Structure
Crystal structure	Monoclinic
Space group	P21/c (No. 14)
Lattice constant	a = 5.53 Å, b = 9.91 Å, c = 12.59 Å α = 90°, β = 99.5°, γ = 90°
Lattice volume (V)	680 Å3
Formula units (Z)	8 units per cell
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Osmium pentafluoride is an inorganic compound with the formula OsF₅. It is a blue-green solid. Like the pentafluorides of Ru, Rh, and Ir, OsF₅ exists as a tetramer in the solid state.

Preparation

Osmium pentafluoride can be prepared by reduction of osmium hexafluoride with iodine as a solution in iodine pentafluoride:^[1]

10 OsF₆ + I₂ → 10 OsF₅ + 2 IF₅

It can also be prepared by treating a solution of osmium hexafluoride in anhydrous hydrogen fluoride with hydrogen or silicon.^[2] Platinum gauze or UV irradiation increase the reaction rate.

References

^ ^a ^b Holloway, John H.; Mitchell, S. J. (1971). "Preparation and Crystal Structure of Osmium Pentafluoride". Journal of the Chemical Society: 2789–94. doi:10.1039/J19710002789.
^ Paine, Robert T.; Asprey, Larned B. (1975-05-01). "Reductive syntheses of transition metal fluoride compounds. Synthesis of rhenium, osmium, and iridium pentafluorides and tetrafluorides". Inorganic Chemistry. 14 (5): 1111–1113. doi:10.1021/ic50147a030. ISSN 0020-1669.

[Holloway-1] Holloway, John H.; Mitchell, S. J. (1971). "Preparation and Crystal Structure of Osmium Pentafluoride". Journal of the Chemical Society: 2789–94. doi:10.1039/J19710002789.

[2] Paine, Robert T.; Asprey, Larned B. (1975-05-01). "Reductive syntheses of transition metal fluoride compounds. Synthesis of rhenium, osmium, and iridium pentafluorides and tetrafluorides". Inorganic Chemistry. 14 (5): 1111–1113. doi:10.1021/ic50147a030. ISSN 0020-1669.

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