Arsenic triselenide

{{chembox

| Watchedfields = changed

| verifiedrevid = 431676226

| Name = Arsenic triselenide

| ImageFile1 = As2Se3.jpg

| ImageFile2 =Unit cell of As2Se3.png

| OtherNames = Arsenic(III) selenide

| Reference =

|Section1={{Chembox Identifiers

| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}

| ChemSpiderID = 14089

| InChI = 1/As2Se3/c3-1-5-2-4

| SMILES = [Se]=[As][Se][As]=[Se]

| InChIKey = WBFMCDAQUDITAS-UHFFFAOYAQ

| StdInChI_Ref = {{stdinchicite|correct|chemspider}}

| StdInChI = 1S/As2Se3/c3-1-5-2-4

| StdInChIKey_Ref = {{stdinchicite|correct|chemspider}}

| StdInChIKey = WBFMCDAQUDITAS-UHFFFAOYSA-N

| CASNo_Ref = {{cascite|correct|CAS}}

| CASNo = 1303-36-2

| PubChem = 14772

| RTECS = CG2285000

| EC_number = 215-119-5

| UNII = XWS0W0GB8G

}}

|Section2={{Chembox Properties

| As=2|Se=3

| Appearance = brown-black powder or metallic gray crystals

| Odor = odorless

| Density = 4.75 g/cm³{{cite book | editor= Haynes, William M. | date = 2016| title = CRC Handbook of Chemistry and Physics | edition = 97th | publisher = CRC Press | isbn = 9781498754293|page=4.49| title-link = CRC Handbook of Chemistry and Physics}}

| Solubility = insoluble

| MeltingPtC = 377

| MeltingPt_ref =

| BoilingPt =

}}

|Section3={{Chembox Structure

| Structure_ref ={{cite journal|doi=10.1107/S0567740873005091|title=Crystalline structures of As₂Se₃ and As₄Se₄|journal=Acta Crystallographica Section B|volume=29|issue=8|pages=1583–1589|year=1973|last1=Renninger|first1=A. L.|last2=Averbach|first2=B. L.|doi-access=|bibcode=1973AcCrB..29.1583R }}

| CrystalStruct = Monoclinic, mP20

| SpaceGroup = P2₁/c, No. 14

| LattConst_a = 0.43 nm

| LattConst_b = 0.994 nm

| LattConst_c = 1.29058 nm

| LattConst_alpha =90

| LattConst_beta =109.927

| LattConst_gamma = 90

| UnitCellFormulas =4

}}

|Section7={{Chembox Hazards

| GHSPictograms = {{GHS06}}{{GHS08}}{{GHS09}}

| GHSSignalWord = Danger

| HPhrases = {{H-phrases|301|330|331|373|410}}

| PPhrases = {{P-phrases|260|261|264|270|271|273|284|301+310|304+340|310|311|314|320|321|330|391|403+233|405|501}}

| NFPA-H = 4

| NFPA-R = 0

| NFPA-F = 0

}}

|Section8={{Chembox Related

| OtherAnions = {{ubl|diarsenic trioxide|diarsenic trisulfide|arsenic(III) telluride}}

| OtherCations = antimony(III) selenide

| OtherCompounds = arsenic(V) selenide

}}

}}

Arsenic triselenide is an inorganic chemical compound with the chemical formula {{chem2|As2Se3|auto=1}}.

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.{{cite journal|doi=10.1016/j.jnoncrysol.2011.03.030|title=Fabrication of highly homogeneous As₂Se₃ glass under argon flow|journal=Journal of Non-Crystalline Solids|volume=357|issue=15|pages=2897–2902|year=2011|last1=Guillevic|first1=Erwan|last2=Zhang|first2=Xianghua|last3=Adam|first3=Jean-Luc|last4=Ma|first4=Hongli|last5=Lucas|first5=Jacques|last6=Tariel|first6=Hugues|bibcode=2011JNCS..357.2897G}}

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