Disulfur dibromide

{{Chembox

| Watchedfields = changed

| verifiedrevid = 408467094

| Name = Disulfur dibromide

| ImageFile1 = Disulfur-dibromide-2D-dimensions.png

| ImageName1 = Ball-and-stick model of sulfur dibromide

| ImageFile2 = Disulfur-dibromide-3D-balls.png

| ImageName2 = Disulfur-dibromide-3D-vdW.png

| ImageCaption2 = {{color box|yellow}} Sulfur, S; {{color box|maroon}} Bromine, Br

| ImageFile3 = Sulphur bromide.jpg

| IUPACName = Disulfur dibromide
Dibromodisulfane

| OtherNames =

| SystematicName = Bromosulfanyl thiohypobromite

| Section1 = {{Chembox Identifiers

| CASNo = 13172-31-1

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

| UNII_Ref = {{fdacite|correct|FDA}}

| UNII = L9DU8F2SHZ

| ChemSpiderID = 109902

| PubChem = 123296

| RTECS =

| EINECS = 236-119-1

| UNNumber =

| SMILES = S(SBr)Br

| StdInChIKey = JIRDGEGGAWJQHQ-UHFFFAOYSA-N

| StdInChI = InChI=1S/Br2S2/c1-3-4-2

}}

| Section2 = {{Chembox Properties

| Formula = {{chem2|S2Br2}}

| S=2|Br=2

| Appearance = Orange/yellow liquid

| Density = 2.703 g/cm³

| Solubility = hydrolyzes

| MeltingPtC = -46

| MeltingPt_ref =

| BoilingPtC = 46-48

| BoilingPt_notes = (0.1 mmHg)

| RefractIndex =

}}

| Section3 = {{Chembox Structure

| Coordination = 2 at sulfur atoms

| MolShape = gauche

| PointGroup = C₂

| Dipole =

}}

| Section4 = {{Chembox Thermochemistry

|DeltaHf = 30.96 kJ/mol{{cite book |author= |year=1999 |title=Thermodynamic Properties of Inorganic Materials · Pure Substances. Part 2 _ Compounds from BeBr_g to ZrCl2_g |url=https://materials.springer.com/bp/docs/978-3-540-49411-9 |publisher=Springer-Verlag Berlin Heidelberg |page=99 |isbn=978-3-540-49411-9 }}

|Entropy = 350.52 J/(mol·K)

}}

| Section7 = {{Chembox Hazards

| ExternalSDS = [http://www.inchem.org/documents/icsc/icsc/eics1661.htm ICSC 1661]

| GHSPictograms = {{GHS05}}{{GHS07}}{{GHS09}}

| GHSSignalWord = Danger

| HPhrases = {{H-phrases|}}

| PPhrases = {{P-phrases|}}

| NFPA-H =

| NFPA-F =

| NFPA-R =

| NFPA-S =

| AutoignitionPt =

| PEL =

}}

| Section8 = {{Chembox Related

| OtherFunction = {{ubl|Sulfur dibromide|Thionyl bromide|Sulfuryl bromide}}

| OtherCompounds = {{ubl|Hydrogen disulfide|Disulfur difluoride|Disulfur dichloride|Disulfur diiodide}}

}}

}}

Disulfur dibromide is the inorganic compound with the formula {{chem2|S2Br2|auto=1}}. It is a yellow-brown liquid that fumes in air. It is prepared by direct combination of the elements and purified by vacuum distillation.{{cite book|author=F. Fehér|chapter=Dibromodisulfane|title=Handbook of Preparative Inorganic Chemistry, 2nd Ed.|editor=G. Brauer|publisher=Academic Press|year=1963|place=NY, NY|volume=1|pages=377–378}} Higher yields can be obtained from disulfur dichloride and 50% aqueous hydrobromic acid, but the product must be promptly removed from water, lest it hydrolyze.{{cite book|title=Sulfur in Organic and Inorganic Chemistry|volume=1|editor-first=Alexander|editor-last=Senning|year=1971|publisher=Marcel Dekker|location=New York|lccn=70-154612|isbn=0-8247-1615-9|first=Philip S.|last=Magee|chapter=The Sulfur–Bromine Bond|pages=264–267}} The compound has no particular application,{{cn|date=November 2024}} unlike the related sulfur compound disulfur dichloride, although acidic alcoholysis is "an excellent synthesis of alkyl bromides."

The molecular structure is {{chem2|Br\sS\sS\sBr}}, akin to that of disulfur dichloride ({{chem2|S2Cl2}}). According to electron diffraction measurements, the angle between the {{chem2|Br^{a}\sS\sS}} and {{chem2|S\sS\sBr^{b}|}} planes is 84° and the {{chem2|Br\sS\sS}} angle is 107°. The {{chem2|S\sS}} distance is 198.0 pm, circa 5.0 pm shorter than for {{chem2|S2Cl2}}.{{cite journal|title=Comparison of the Structural Properties of Compounds Containing the XSSX Moiety (X = H, Me, R, Cl, Br, F, OR)|last1=Zysman-Colman|first1=Eli|last2=Harpp|first2=David|journal=Journal of Sulfur Chemistry|year=2004|volume=25|issue=4 |page=291-316|doi=10.1080/17415990410001710163|s2cid=95468251}}