Arsenic triselenide

Arsenic triselenide is an inorganic chemical compound with the chemical formula As₂Se₃.

Arsenic triselenide

Names
Other names Arsenic(III) selenide
Identifiers
CAS Number	1303-36-2 Y
3D model (JSmol)	Interactive image
ChemSpider	14089 Y
ECHA InfoCard	100.013.745
EC Number	215-119-5
PubChem CID	14772
RTECS number	CG2285000
UNII	XWS0W0GB8G
CompTox Dashboard (EPA)	DTXSID7061645
InChI InChI=1S/As2Se3/c3-1-5-2-4 Y Key: WBFMCDAQUDITAS-UHFFFAOYSA-N Y InChI=1/As2Se3/c3-1-5-2-4 Key: WBFMCDAQUDITAS-UHFFFAOYAQ
SMILES [Se]=[As][Se][As]=[Se]
Properties
Chemical formula	As2Se3
Molar mass	386.756 g·mol−1
Appearance	brown-black powder[1] or metallic gray crystals
Odor	odorless
Density	4.75 g/cm3[1]
Melting point	377 °C (711 °F; 650 K)[1]
Solubility in water	insoluble[1]
Structure[2]
Crystal structure	Monoclinic, mP20
Space group	P21/c, No. 14
Lattice constant	a = 0.43 nm, b = 0.994 nm, c = 1.29058 nm α = 90°, β = 109.927°, γ = 90°
Formula units (Z)	4
Hazards
GHS labelling:
Pictograms
Signal word	Danger
Hazard statements	H301, H330, H331, H373, H410
Precautionary statements	P260, P261, P264, P270, P271, P273, P284, P301+P310, P304+P340, P310, P311, P314, P320, P321, P330, P391, P403+P233, P405, P501
NFPA 704 (fire diamond)	4 0 0
Related compounds
Other anions	diarsenic trioxide diarsenic trisulfide arsenic(III) telluride
Other cations	antimony(III) selenide
Related compounds	arsenic(V) selenide
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Y verify (what is YN ?) Infobox references

Amorphous arsenic triselenide is used as a chalcogenide glass for infrared optics. When purified, it transmits light with wavelengths between ca. 0.7 and 19 μm.^[3]

In arsenic triselenide, arsenic is covalently bonded to selenium, where arsenic has a formal oxidation state of +3, and selenium −2.

Solution processed thin film As2Se3

Thin film selenide glasses have emerged as an important material for integrated photonics due to its high refractive index, mid-IR transparency and high non-linear optical indices. High-quality As₂Se₃ glass films can be deposited from spin coating method from ethylenediamine solutions.^[4]