Urandiselenid

General
Surname	Urandiselenid
other names	Uranium selenide (ambiguous)
Molecular formula	USe 2
Brief description	black solid
External identifiers / databases
EC number	235-245-4
ECHA InfoCard	100.032.029
PubChem	82939
Wikidata	Q15634280
properties
Molar mass	395.95 g mol −1
Physical state	firmly
density	8.89 g cm −3 (α); 9.08 g cm −3 (β); 9.0 g cm −3 (γ);
Melting point	1460 ° C (α-form); 1350-1380 ° C (β-form);
Hazard and safety information
	; Radioactive
H and P phrases	H: 300-330-373-410
	P: ?
	As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Urandiselenide is an inorganic chemical compound of uranium from the group of selenides . In addition to this, further uranium selenides are known with USe ₃ , U ₃ Se ₅ , U ₂ Se ₃ , U ₃ Se ₄ and USe, and another oxide selenide of uranium is known with UOSe.

presentation

α-uranium diselenide can be obtained by reacting uranium triselenide with hydrogen at 700 ° C.

{\ displaystyle {\ ce {USe3 + H2 -> USe2 + H2Se}}}

β- and γ-uranium diselenide can be produced by thermal degradation of uranium triselenide in a high vacuum, with β-uranium diselenide and γ-uranium diselenide being formed at 575 ° C. at 760 ° C.

{\ displaystyle {\ ce {USe3 -> USe2 + Se}}}

properties

Urandiselenide is a black, crystalline solid that occurs in three polymorphic modifications. The α-form has a tetragonal , the β-form an orthorhombic ( lead (II) chloride type with the space group Pnma (space group no. 62) with the lattice constants a = 7.4552 Å, b = 4.2320 Å , c = 8.964 Å and the γ-form a hexagonal crystal structure . Template: room group / 62

Individual evidence

↑ ^a ^b ^c ^d ^e ^f ^g ^h ⁱ Georg Brauer (Ed.), With the collaboration of Marianne Baudler u. a .: Handbook of Preparative Inorganic Chemistry. 3rd, revised edition. Volume II, Ferdinand Enke, Stuttgart 1978, ISBN 3-432-87813-3 , p. 1232.

↑ Jane E. Macintyre: Dictionary of Inorganic Compounds . CRC Press, 1992, pp. 3809 ( limited preview in Google Book search).

↑ Harmonized classification and labeling of selenium compounds with the exception of cadmium sulphoselenide and those specified elsewhere in this Annex in the Classification and Labeling Inventory of the European Chemicals Agency (ECHA), accessed on March 18, 2017.

↑ Not explicitly listed in Regulation (EC) No. 1272/2008 (CLP) , but with the indicated labeling it falls under the group entries on uranium compounds with the exception of those specified elsewhere in this Annex and selenium compounds with the exception of cadmium sulphoselenide and those specified elsewhere in this Annex in the Classification and Labeling Inventory of the European Chemicals Agency (ECHA), accessed on March 18, 2017. Manufacturers or distributors can expand the harmonized classification and labeling .

↑ The hazards emanating from radioactivity do not belong to the properties to be classified according to the GHS labeling.

^ Leopold Gmelin: Uranium: Supplement volume . 1981, ISBN 978-0-387-93433-4 , pp. i ( limited preview in Google Book Search).

↑ H. Noël et al. : Crystal Structure and Physical Properties of β-USe ₂ and USe _{2 - x} Te _x (x = 0.24 and 0.72) . In: Journal of Solid State Chemistry . tape 126 , no. 1 , October 1996, p. 22-26 , doi : 10.1006 / jssc.1996.0304 .

[brauer-1] ↑ ^a ^b ^c ^d ^e ^f ^g ^h ⁱ Georg Brauer (Ed.), With the collaboration of Marianne Baudler u. a .: Handbook of Preparative Inorganic Chemistry. 3rd, revised edition. Volume II, Ferdinand Enke, Stuttgart 1978, ISBN 3-432-87813-3 , p. 1232.

[Jane_E._Macintyre-2] Jane E. Macintyre: Dictionary of Inorganic Compounds . CRC Press, 1992, pp. 3809 ( limited preview in Google Book search).

[3] Template: CL Inventory / harmonized Harmonized classification and labeling of selenium compounds with the exception of cadmium sulphoselenide and those specified elsewhere in this Annex in the Classification and Labeling Inventory of the European Chemicals Agency (ECHA), accessed on March 18, 2017.