Mercury(II) bromide
{{chembox
| Verifiedfields = changed
| Watchedfields = changed
| verifiedrevid = 438049564
| ImageFile = HgBr2-xtal-1990-CM-3D-balls.png
| ImageSize = 250 px
| ImageName = Mercury(II) bromide
| IUPACName = Mercury(II) bromide
| OtherNames = Mercuric bromide
|Section1={{Chembox Identifiers
| CASNo_Ref = {{cascite|correct|CAS}}
| CASNo = 7789-47-1
| ChEBI = 49639
| ChemSpiderID = 23014
| EC_number = 232-169-3
| PubChem = 24612
| UNNumber = 1634
| UNII_Ref = {{fdacite|correct|FDA}}
| UNII = P986675T8V
| RTECS = OV7415000
| StdInChI=1S/2BrH.Hg/h2*1H;/q;;+2/p-2
| StdInChIKey = NGYIMTKLQULBOO-UHFFFAOYSA-L
| SMILES = Br[Hg]Br
}}
|Section2={{Chembox Properties
| Formula = HgBr2
| MolarMass = 360.41 g/mol
| Appearance = white solid
| Density = 6.03 g/cm3, solid
| Solubility = 0.6 g/100 mL (25°C)
| SolubleOther = 30 g/100 mL (25°C) ethanol
| SolubilityProduct =
| MeltingPtC = 237
| BoilingPtC = 322
| MagSus = −94.2·10−6 cm3/mol
}}
|Section3={{Chembox Structure
| MolShape =
| Coordination = rhombic
| CrystalStruct =
| Dipole =
}}
|Section7={{Chembox Hazards
| GHSPictograms = {{GHS06}}{{GHS08}}{{GHS09}}
| GHS_ref= {{Cite PubChem|cid=24612|title=Mercuric bromide|access-date=2021-11-25}}
| GHSSignalWord = Danger
| HPhrases = {{H-phrases|H300|H310|H330|H373|H410}}
| PPhrases = {{P-phrases|P260|P262|P264|P270|P271|P273|P280|P284|P301+P310|P302+P350|P304+P340|P310|P314|P320|P321|P322|P330|P361|P363|P391|P403+P233|P405|P501}}
| NFPA-H = 3
| NFPA-F = 0
| NFPA-R = 2
| NFPA-S =
| FlashPt = Non-flammable
}}
|Section8={{Chembox Related
| OtherAnions = Mercury(II) fluoride
Mercury(II) chloride
Mercury(II) iodide
| OtherCations = Zinc bromide
Cadmium bromide
Mercury(I) bromide
}}
}}
Mercury(II) bromide or mercuric bromide is an inorganic compound with the formula HgBr2.{{Cite web |last=PubChem |title=Mercury bromide (Hg2Br2) |url=https://pubchem.ncbi.nlm.nih.gov/compound/24829 |access-date=2022-12-22 |website=pubchem.ncbi.nlm.nih.gov |language=en}} This white solid is a laboratory reagent.{{Cite web |last=Elements |first=American |title=Mercury Bromide |url=https://www.americanelements.com/mercury-bromide-7789-47-1 |access-date=2022-12-22 |website=American Elements |language=en}} Like all mercury salts, it is highly toxic.
Preparation
Mercury(II) bromide can be produced by reaction of metallic mercury with bromine.{{cite book|author1=F. Wagenknecht|author2=R. Juza|chapter=Mercury(II) bromide|title=Handbook of Preparative Inorganic Chemistry, 2nd Ed. |editor=G. Brauer|publisher=Academic Press|year=1963|place=NY, NY|volume=2|pages=1109}}
Reactions
Mercury(II) bromide is used as a reagent in the Koenigs–Knorr reaction, which forms glycoside linkages on carbohydrates.
{{Citation
| last = Horton
| first = Derek
| year = 2004
| title = Advances in Carbohydrate Chemistry and Biochemistry
| location = Amsterdam
| publisher = Elsevier Academic Press
| isbn = 0-12-007259-9
| pages = 76
| url = https://books.google.com/books?id=E22gW9CbU_0C&q=%22mercury(II)+bromide%22&pg=PA76
| access-date = 2008-05-29
{{Citation
| last = Stick
| first = Robert V.
| year = 2001
| title = Carbohydrates: The Sweet Molecules of Life
| location = San Diego
| publisher = Academic Press
| isbn = 0-12-670960-2
| pages = 125
| url = https://books.google.com/books?id=-MtjsUMB6ogC&q=%22mercury(II)+bromide%22&pg=PA125
| access-date = 2008-05-29
}}
It is also used to test for the presence of arsenic, as recommended by the European Pharmacopoeia.
{{Citation
| last = Pederson
| first = Ole
| year = 2006
| title = Pharmaceutical Chemical Analysis
| location = Boca Raton, Florida
| publisher = CRC Press
| isbn = 0-8493-1978-1
| pages = 107
| url = https://books.google.com/books?id=R7ZxXS5DZj8C&q=%22mercury(II)+bromide%22&pg=PT125
| access-date = 2008-05-29
}}
The arsenic in the sample is first converted to arsine gas by treatment with hydrogen. Arsine reacts with mercury(II) bromide:
{{Citation
| last1 = Odegaard
| first1 = Nancy
| last2 = Sadongei
| first2 = Alyce
| year = 2005
| title = Old Poisons, New Problems
| publisher = Rowman Altamira
| isbn = 0-7591-0515-4
| pages = 58
| url = https://books.google.com/books?id=QLU0SVlruCMC&q=%22mercury(II)+bromide%22&pg=PA58
| access-date = 2008-05-29
}}
:AsH3 + 3HgBr2 → As(HgBr)3 + 3HBr
The white mercury(II) bromide will turn yellow, brown, or black if arsenic is present in the sample.
{{Citation
| last1 = Townsend
| first1 = Timothy G.
| last2 = Solo-Gabriele
| first2 = Helena
| year = 2006
| title = Environmental Impacts of Treated Wood
| location = Boca Raton, Florida
| publisher = CRC Press
| isbn = 0-8493-6495-7
| pages = 339
| url = https://books.google.com/books?id=ENJL1UMdGTUC&q=%22mercury(II)+bromide%22&pg=PT361
| access-date = 2008-05-29
}}
Mercury(II) bromide reacts violently with elemental indium at high temperatures
{{Citation
| last1 = Bretherick
| first1 = L.
| last2 = Urben
| first2 = P. G.
| last3 = Pitt
| first3 = Martin John
| year = 1999
| title = Bretherick's Handbook of Reactive Chemical Hazards
| publisher = Elsevier Academic Press
| isbn = 0-7506-3605-X
| pages = 110
}}
and, when exposed to potassium, can form shock-sensitive explosive mixtures.
{{Citation
| last1 = Bretherick
| first1 = L.
| last2 = Urben
| first2 = P. G.
| last3 = Pitt
| first3 = Martin John
| year = 1999
| title = Bretherick's Handbook of Reactive Chemical Hazards
| publisher = Elsevier Academic Press
| isbn = 0-7506-3605-X
| pages = 1276
}}
References
{{Reflist}}
{{Mercury compounds}}
{{bromine compounds}}
{{Authority control}}