Sodium arsenide

Sodium arsenide, also known as trisodium arsenide, is the inorganic compound of sodium and arsenic with the formula Na₃As.^[1] It is a dark colored solid that degrades upon contact with water or air. It is prepared by the reaction of the elements at 200–400 °C.^[2] The compound is mainly of interest as exhibiting an archetypal structure. The normal pressure "sodium arsenide" phase is adopted by many alkali metal pnictides. At 3.6 gigapascals, Na₃As adopts the Li₃Bi structure, which is another archetypal structure.^[3] Sodium arsenide is a crystalline solid used as a semiconductor and in photo optic applications. Its IUPAC name is disodioarsanylsodium.

At high pressures, Na₃As adopts this cubic structure (the so-called Li₃Bi motif).

Sodium arsenide

Names
IUPAC name Disodioarsanylsodium
Identifiers
CAS Number	12044-25-6
3D model (JSmol)	Interactive image
ChemSpider	74787
ECHA InfoCard	100.031.762
EC Number	234-952-5
PubChem CID	82879
CompTox Dashboard (EPA)	DTXSID0065222
InChI InChI=1S/As.3Na Key: MMQSOEGXVXPNSH-UHFFFAOYSA-N
SMILES [Na][As]([Na])[Na]
Properties
Chemical formula	Na3As
Molar mass	143.89 g·mol−1
Appearance	Violet brown solid
Density	2.36 g·cm−3
Solubility in water	Hydrolysis
Hazards
Occupational safety and health (OHS/OSH):
Main hazards	Toxic, releases AsH3
Related compounds
Other anions	Sodium nitride, sodium phosphide, sodium antimonide
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references