Chemistry:Aluminium selenide

Aluminium selenide

Names
Other names Aluminium(III) selenide
Identifiers
CAS Number	1302-82-5 Y
3D model (JSmol)	Interactive image
ChemSpider	144477 Y
EC Number	215-110-6
PubChem CID	164804
UNII	4R7PMP996Q
CompTox Dashboard (EPA)	DTXSID80894848
InChI InChI=1S/2Al.3Se/q2*+3;3*-2 Y Key: CYRGZAAAWQRSMF-UHFFFAOYSA-N Y InChI=1/2Al.3Se/q2*+3;3*-2 Key: CYRGZAAAWQRSMF-UHFFFAOYAJ
SMILES [Al+3].[Al+3].[Se-2].[Se-2].[Se-2]
Properties
Chemical formula	Al2Se3
Molar mass	290.84 g/mol
Appearance	yellow to brown powder
Odor	odorless
Density	3.437 g/cm3
Melting point	947 °C (1,737 °F; 1,220 K)
Solubility in water	decomposes
Structure
Crystal structure	Monoclinic, mS20, Space group Cc, No. 9
Thermochemistry
Std molar entropy (So298)	154.8 J/mol K
Std enthalpy of formation (ΔfH⦵298)	-566.9 kJ/mol
Hazards
GHS pictograms
GHS Signal word	Danger
GHS hazard statements	H301, H331, H373, H410
GHS precautionary statements	P260, P261, P264, P270, P271, P273, P301+310, P304+340, P311, P314, P321, P330, P391, P403+233, P405, P501
NFPA 704 (fire diamond)	0 3 3
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Infobox references

Aluminium selenide is the inorganic compound with the formula Al₂Se₃.

Preparation

It is a solid prepared by igniting a mixture of the elements at 1,000 °C (1,830 °F):

2 Al + 3 Se → Al₂Se₃

The pure compound is white, but typical samples are coloured. Samples are usually protected from moisture, because they hydrolyze readily, giving off highly toxic hydrogen selenide gas:

Al₂Se₃ + 3 H₂O → Al₂O₃ + 3 H₂Se

Use

Al₂Se₃ has been used as a precursor to hydrogen selenide, which is released when the solid is treated with acids.