selenium tetrabromide
{{Chembox
| Name =
| ImageFile1 = Selenium tetrabromide.jpg
| ImageSize1 =
| ImageFile2 = Selenium-tetrabromide-tetramer-from-alpha-xtal-3D-bs-17.png
| IUPACName = Tetrabromo-λ4-selane
| OtherNames = Selenium tetrabromide, selenium(IV) bromide
| SystematicName =
| Section1 = {{Chembox Identifiers
| CASNo = 7789-65-3
| EC_number = 232-181-9
| UNII = 8O54YXR180
| PubChem = 82246
| ChemSpiderID = 74224
| SMILES = Br[Se](Br)(Br)Br
| InChI = 1/Br4Se/c1-5(2,3)4
| InChIKey = VTQZBGAODFEJOW-UHFFFAOYAY
| StdInChI = 1S/Br4Se/c1-5(2,3)4
| StdInChIKey = VTQZBGAODFEJOW-UHFFFAOYSA-N
}}
| Section2 = {{Chembox Properties
| Formula = SeBr4
| MolarMass = 398.576
| Appearance =
| Density = 4.029 g/cm3
| MeltingPtC = 75
| MeltingPt_notes = (dissolves)
| BoilingPtC = 115
| BoilingPt_notes = (sublimes)
| Solubility =
}}
| Section3 = {{Chembox Structure
| CrystalStruct = trigonal (α)
monoclinic (β)
| SpaceGroup = P31c, No. 159 (α)
C2/c, No.15 (β)
| UnitCellFormulas = 16
}}
| Section4 = {{Chembox Hazards
| MainHazards =
| FlashPt =
| AutoignitionPt =
| GHSPictograms = {{GHS05}}{{GHS06}}{{GHS08}}{{GHS09}}
| GHSSignalWord = Danger
| HPhrases = {{H-phrases|301|311|314|331|351|373|410}}
| PPhrases = {{P-phrases|201|202|260|261|264|270|271|273|280|281|301+310|301+330+331|302+352|303+361+353|304+340|305+351+338|308+313|310|311|312|314|321|322|330|361|363|391|403+233|405|501}}
}}
| Section5 =
| Section6 =
|Section8={{Chembox Related
| OtherAnions = Selenium tetrafluoride
Selenium tetrachloride
| OtherCations = Tellurium tetrabromide
| OtherCompounds = Selenium dibromide
}}
}}
Selenium tetrabromide is an inorganic compound with a chemical formula SeBr4.
Preparation
Selenium tetrabromide could be produced by mixing elemental bromine and selenium:{{Greenwood&Earnshaw|pages=772-774}}{{cite journal|last1=Tideswell|first1=N. W.|last2=McCullough|first2=J. D.|year=1956|title=Selenium Bromides. I. A Spectrophotometric Study of the Dissociation of Selenium Tetrabromide and Selenium Dibromide in Carbon Tetrachloride Solution1,2|journal=Journal of the American Chemical Society|volume=78|issue=13|pages=3026–3029|doi=10.1021/ja01594a025}}
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Properties
Selenium tetrabromide exists in two polymorphs, the trigonal, black α-SeBr4 and the monoclinic, orange-reddish β-SeBr4, both of which feature tetrameric cubane-like Se4Br16 units but differ in how they are arranged.{{Cite journal|last1=Born|first1=Ref. P.|last2=Kniep|first2=R.|last3=Mootz|first3=D.|date=1979|title=Phasenbeziehungen im System Se-Br und die Kristallstrukturen des dimorphen SeBr4|url=https://onlinelibrary.wiley.com/doi/abs/10.1002/zaac.19794510103|journal=Z. Anorg. Allg. Chem.|volume=451|issue=1|pages=12–24|doi=10.1002/zaac.19794510103}} It dissolves in carbon disulfide, chloroform and ethyl bromide, but decomposes in water,{{Cite book|last=Perry|first=Dale L.|title=Handbook of Inorganic Compounds|publisher=CRC Press|year=2011|isbn=978-1-4398-1461-1|pages=360}} so that it produces selenous acid in wet air.
The compound is only stable under a bromine-saturated atmosphere; gas phase measurements of the gas density indicate that the compound decomposes into selenium monobromide and bromine.
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References
{{reflist}}
{{Selenium compounds}}
{{Bromides}}
{{Bromine compounds}}