Article · Wikipedia archive · Last revised Jul 9, 2026

Arsenic triselenide

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

Last revised
Jul 9, 2026
Read time
≈ 2 min
Length
427 w
Citations
7
Source
Arsenic triselenide
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Names
Other names
Arsenic(III) selenide
Identifiers
3D model (JSmol)
ChemSpider
ECHA InfoCard 100.013.745
EC Number
  • 215-119-5
RTECS number
  • CG2285000
UNII
  • InChI=1S/As2Se3/c3-1-5-2-4 checkY
    Key: WBFMCDAQUDITAS-UHFFFAOYSA-N checkY
  • InChI=1/As2Se3/c3-1-5-2-4
    Key: WBFMCDAQUDITAS-UHFFFAOYAQ
  • [Se]=[As][Se][As]=[Se]
Properties
As2Se3
Molar mass 386.756 g·mol−1
Appearance brown-black powder1 or metallic gray crystals
Odor odorless
Density 4.75 g/cm31
Melting point 377 °C (711 °F; 650 K)1
insoluble1
Structure2
Monoclinic, mP20
P21/c, No. 14
a = 0.43 nm, b = 0.994 nm, c = 1.29058 nm
α = 90°, β = 109.927°, γ = 90°
4
Hazards
GHS labelling:
GHS06: ToxicGHS08: Health hazardGHS09: Environmental hazard
Danger
H301, H330, H331, H373, H410
P260, P264, P270, P271, P273, P284, P301+P310, P304+P340, P310, P311, P314, P320, P321, P330, P391, P403+P233, P405, P501
NFPA 704 (fire diamond)
Related compounds
Other anions
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).
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Arsenic triselenide is an inorganic chemical compound with the chemical formula As2Se3.

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

References

References

  1. Haynes, William M., ed. (2016). CRC Handbook of Chemistry and Physics (97th ed.). CRC Press. p. 4.49. ISBN 9781498754293.
  2. Renninger, A. L.; Averbach, B. L. (1973). "Crystalline structures of As2Se3 and As4Se4". Acta Crystallographica Section B. 29 (8): 1583–1589. Bibcode:1973AcCrB..29.1583R. doi:10.1107/S0567740873005091.
  3. Guillevic, Erwan; Zhang, Xianghua; Adam, Jean-Luc; Ma, Hongli; Lucas, Jacques; Tariel, Hugues (2011). "Fabrication of highly homogeneous As2Se3 glass under argon flow". Journal of Non-Crystalline Solids. 357 (15): 2897–2902. Bibcode:2011JNCS..357.2897G. doi:10.1016/j.jnoncrysol.2011.03.030.
  4. Zou, Yi; Lin, Hongtao; Ogbuu, Okechukwu; Li, Lan; Danto, Sylvain; Novak, Spencer; Novak, Jacklyn; Musgraves, J. David; Richardson, Kathleen; Hu, Juejun (2012). "Effect of annealing conditions on the physio-chemical properties of spin-coated As2Se3 chalcogenide glass films". Optical Materials Express. 2 (12): 1723. Bibcode:2012OMExp...2.1723Z. doi:10.1364/OME.2.001723. S2CID 32070511.