β form
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3D model (JSmol)
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ChemSpider | |
ECHA InfoCard | 100.033.991 |
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Properties | |
UF5 | |
Molar mass | 333.02 g/mol |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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what is ?) | (|
Infobox references | |
Uranium pentafluoride is the inorganic compound with the chemical formula UF5. It is a pale yellow paramagnetic solid. The compound has attracted interest because it is related to uranium hexafluoride, which is widely used to produce uranium fuel. It crystallizes in two polymorphs, called α- and β-UF5.
It can be produced by reduction of the hexafluoride with carbon monoxide at elevated temperatures.
Other reducing agents have been examined.
The α form is a linear coordination polymer consisting of chains of octahedral uranium centers in which one of the five fluoride anion forms a bridge to the next uranium atom. The structure is reminiscent of that for vanadium pentafluoride.
In β form, the uranium centers adopt a square antiprismatic structure. The β polymorph gradually converts to α at 130 °C.
Of theoretical interest, molecular UF5 can be generated as a transient monomer by UV-photolysis of uranium hexafluoride. It is thought to adopt a square pyramidal geometry.