Uranium disulfide

Uranium disulfide is an inorganic chemical compound of uranium in oxidation state +4 and sulfur in oxidation state −2. It is radioactive and appears in the form of black crystals.^[2]

Uranium disulfide

Identifiers
CAS Number	12039-14-4
3D model (JSmol)	Interactive image
ChemSpider	23349340
ECHA InfoCard	100.031.700
EC Number	234-884-6
PubChem CID	131700999
CompTox Dashboard (EPA)	DTXSID2065204
InChI InChI=1S/2S.U/q2*-2;+4 Key: OYHHCKFHGQELGK-UHFFFAOYSA-N
SMILES [S-2].[S-2].[U+4]
Properties
Chemical formula	US2
Molar mass	302.160 g/mol
Appearance	Black crystals
Structure[1]
Crystal structure	Tetragonal (α-US2)
Space group	P4/ncc (No. 130)
Lattice constant	a = 1029.3 pm, c = 637.4 pm
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Uranium disulfide has two allotropic forms: α-uranium disulfide, which is stable above the transition temperature (about 1350 °C) and metastable below it, and β-uranium disulfide which is stable below this temperature.^[3] The tetragonal crystal structure of α-US₂ is identical to α-USe₂.^[1]

Uranium disulfide can be synthesized by reduction of gaseous hydrogen sulfide with uranium metal powder at elevated temperatures.^[4]