Uranium pentachloride

Uranium pentachloride is an inorganic chemical compound composed of uranium in the +5 oxidation state and five chlorine atoms.
Preparation.
Uranium pentachloride can be prepared from the reaction of uranium trioxide with carbon tetrachloride, with a previously prepared amount of the compound serving as a catalyst.
It can also be prepared from the reaction between uranium tetrachloride and chlorine in a fluidized bed reactor at 550 °C.
Properties.
Uranium pentachloride is available as red-brown microcrystalline powders or black-red crystals with metallic sheen. It is very hygroscopic and decomposes into uranium hexachloride and uranium tetrachloride when in water or heated. There are two crystalline forms, each of which has the uranium atom in an octahedral geometry among six chlorine atoms. Usually, it is in the α-form, which has a monoclinic crystal structure with space group "P"21/"n". The β-form is triclinic with space group "P".
The gaseous form has C4v symmetry. 