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.
Synthesis and structure
Uranium pentafluoride is an intermediate in the conversion of
uranium tetrafluoride to volatile UF6:
2UF4 + F2 → 2UF5
2UF5 + F2 → 2UF6
It can be produced by reduction of the hexafluoride with
carbon monoxide at elevated temperatures.[1]
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.[3] The structure is reminiscent of that for
vanadium pentafluoride.
^Gordon W. Halstead, P. Gary Eller "Uranium(V) Fluorides and Alkoxides" Inorganic Syntheses 1982, volume 21, 162.
doi:
10.1002/9780470132524.ch35
^Eller, P. G.; Larson, A. C.; Peterson, J. R.; Ensor, D. D.; Young, J. P. (1979). "Crystal Structures of α-UF5 and U2F9 and Spectral Characterization of U2F9". Inorganica Chimica Acta. 37 (2): 129–133.
doi:
10.1016/S0020-1693(00)95530-0.