Osmium hexafluoride, also osmium(VI) fluoride, (OsF
6) is a compound of
osmium
Osmium (from Greek grc, ὀσμή, osme, smell, label=none) is a chemical element with the symbol Os and atomic number 76. It is a hard, brittle, bluish-white transition metal in the platinum group that is found as a trace element in alloys, mos ...
and
fluorine
Fluorine is a chemical element with the symbol F and atomic number 9. It is the lightest halogen and exists at standard conditions as a highly toxic, pale yellow diatomic gas. As the most electronegative reactive element, it is extremely reacti ...
, and one of the seventeen known binary
hexafluoride
A hexafluoride is a chemical compound with the general formula QXnF6, QXnF6m−, or QXnF6m+. Many molecules fit this formula. An important hexafluoride is hexafluorosilicic acid (H2SiF6), which is a byproduct of the mining of phosphate rock. In ...
s.
Synthesis
Osmium hexafluoride is made by a direct reaction of osmium metal exposed to an excess of elemental
fluorine
Fluorine is a chemical element with the symbol F and atomic number 9. It is the lightest halogen and exists at standard conditions as a highly toxic, pale yellow diatomic gas. As the most electronegative reactive element, it is extremely reacti ...
gas at 300 °C.
: + 3 →
Description
Osmium hexafluoride is a yellow crystalline solid that melts at 33.4 °C and boils at 47.5 °C.
The solid structure measured at −140 °C is
orthorhombic
In crystallography, the orthorhombic crystal system is one of the 7 crystal systems. Orthorhombic lattices result from stretching a cubic lattice along two of its orthogonal pairs by two different factors, resulting in a rectangular prism with a r ...
space group ''Pnma''.
Lattice parameters
Lattice may refer to:
Arts and design
* Latticework, an ornamental criss-crossed framework, an arrangement of crossing laths or other thin strips of material
* Lattice (music), an organized grid model of pitch ratios
* Lattice (pastry), an orna ...
are ''a'' = 9.387
Å, ''b'' = 8.543 Å, and ''c'' = 4.944 Å. There are four
formula units (in this case, discrete molecules) per
unit cell, giving a density of 5.09 g·cm
−3.
The OsF
6 molecule itself (the form important for the liquid or gas phase) has
octahedral molecular geometry
In chemistry, octahedral molecular geometry, also called square bipyramidal, describes the shape of compounds with six atoms or groups of atoms or ligands symmetrically arranged around a central atom, defining the vertices of an octahedron. The oc ...
, which has point group (''
Oh''). The Os–F
bond length is 1.827 Å.
Partial hydrolysis of OsF
6 produces OsOF
4.
References
['']CRC Handbook of Chemistry and Physics
The ''CRC Handbook of Chemistry and Physics'' is a comprehensive one-volume reference resource for science research. First published in 1914, it is currently () in its 103rd edition, published in 2022. It is sometimes nicknamed the "Rubber Bible ...
'', 90th Edition, CRC Press, Boca Raton, Florida, 2009, , Section 4, ''Physical Constants of Inorganic Compounds'', p. 4-85.
Further reading
* ''
Gmelins Handbuch der anorganischen Chemie'', System Nr. 53, Osmium, Supplement Volume 1, pp. 111–114.
External links
Osmium hexafluoride at webelements.com
{{fluorine compounds
Osmium compounds
Hexafluorides
Platinum group halides
Octahedral compounds