Lead(II) bromide: Difference between revisions

| Verifiedfields = changed

| verifiedrevid =

| ImageFile2 = Lead(II)-bromide-xtal-3x3x3-3D-sf.png

|Section1={{Chembox Identifiers

| CASNo = 10031-22-8

| CASNo_Ref = {{cascite}}

| =

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

| UNII = 1O767M99U7

| PubChem = 24831

| ChemSpiderID = 23216

| SMILES = Br[Pb]Br

| StdInChI = 1S/2BrH.Pb/h2*1H;/q;;+2/p-2

| StdInChIKey = ZASWJUOMEGBQCQ-UHFFFAOYSA-L

|Section2={{Chembox Properties

| Formula = PbBr₂

| MolarMass = 367.01 g/mol

| Appearance = white powder

| Density = 6.66 g/cm³ <ref></ref>

| =

| = 916

| BoilingPt_notes = (vaporizes)

| Solubility = 0.455 g/100 mL (0 °C) <br> 0. g/100 mL (20 °C) <br> 4.41 g/100 mL (100 °C)

| SolubilityProduct = . x 10

| SolubleOther = insoluble in [[alcohol]]; <br> soluble in [[ammonia]], [[alkali]], [[potassium bromide|KBr]], [[sodium bromide|NaBr]]

| MagSus = &minus;90.6·10⁻⁶ cm³/mol

| Section3 = {{Chembox

| Structure_ref = <ref name=Lumbreras1986 />

| CrystalStruct = [[Lead(II) chloride|PbCl₂]] type (orthorhombic)

| SpaceGroup = Pnma (No. 62)

| =

| LattConst_a = 805.90 pm

| = 0

| LattConst_c = 473.19 pm

| LattConst_alpha =

| LattConst_beta =

| LattConst_gamma =

| LattConst_ref =

| LattConst_Comment =

| UnitCellVolume =

| UnitCellFormulas = 4

| Coordination =

| MolShape =

| OrbitalHybridisation =

| Dipole =

|={{Chembox

| ExternalSDS =

| NFPA-H = 3

| NFPA-F = 0

| NFPA-R = 0

| GHSPictograms = {{GHS07}}{{GHS08}}{{GHS09}}

| GHSSignalWord = Danger

| HPhrases = {{H-phrases|302|332|360|373|410}}

| PPhrases = {{P-phrases|201|202|260|261|264|270|271|273|281|301+312|304+312|304+340|308+313|312|314|330|391|405|501}}

}}

|Section8={{Chembox Related

| OtherAnions = [[Lead(II) fluoride]],<br/>[[Lead(II) chloride]],<br/>[[Lead(II) iodide]]

| OtherCations = [[Thallium(I) bromide]],<br/>[[Tin(II) bromide]]<br/>[[Bismuth bromide]]

'''Lead(II) bromide''' is the [[inorganic compound]] with the formula PbBr₂. It is a white powder. It is produced in the burning of typical leaded gasolines.<ref name=Ullmann>Michael J. Dagani, Henry J. Barda, Theodore J. Benya, David C. Sanders "Bromine Compounds" in Ullmann's Encyclopedia of Industrial Chemistry" Wiley-VCH, Weinheim, 2000.{{doi|10.1002/14356007.a04_405}}</ref>

==Preparation and properties==

It is typically prepared from treating solutions of lead salts (e.g., ([[lead(II) nitrate]]) with bromide salts. This process exploits its low solubility in water - only 0.455 g dissolves in 100 g of water at 0 °C. It is about ten times more soluble in boiling water.<ref>{{Greenwood&Earnshaw}}</ref>

PbBr₂ has the same [[crystal structure]] as [[Lead(II) chloride|lead chloride]] ([[cotunnite]]) – they are [[Isomorphism (crystallography)|isomorphous]]. In this structure, Pb²⁺ is surrounded by nine Br⁻ ions in a distorted [[Tricapped trigonal prismatic molecular geometry|tricapped trigonal prismatic]] geometry. Seven of the Pb-Br distances are shorter, in the range 2.9-3.3 Å, while two of them are longer at 3.9 Å. The coordination is therefore sometimes described as (7+2).<ref>{{Greenwood&Earnshaw|pages=382}}</ref><ref name=Lumbreras1986>{{ cite journal | title = Structure and ionic conductivity of mixed lead halides PbCl_2xBr_2(1−x). II | first1 = M. | last1 = Lumbreras | first2 = J. | last2 = Protas | first3 = S. | last3 = Jebbari | first4 = G. J. | last4 = Dirksen | first5 = J. | last5 = Schoonman | journal = [[Solid State Ionics|Solid State Ion.]] | volume = 20 | issue = 4 | year = 1986 | pages = 295–304 | doi = 10.1016/0167-2738(86)90049-4 }}</ref>

Lead bromide was prevalent in the environment as the result of the use of leaded gasoline. [[Tetraethyl lead]] was once widely used to improve the combustion properties of gasoline. To prevent the resulting lead oxides from fouling the engine, gasoline was treated with [[1,2-Dibromoethane]], which converted lead oxides into the more volatile lead bromide, which was then exhausted from the engine into the environment.<ref name=Ullmann/>

==Safety==

Like other compounds containing lead, lead(II) bromide is categorized as ''probably carcinogenic to humans'' (Category 2A), by the [[International Agency for Research on Cancer]] (IARC). Its release into the environment as a product of leaded gasoline was highly controversial.

==References==

{{reflist}}

{{Lead compounds}}

{{bromine compounds}}

{{bromides}}

[[:(II)]]

[[Category:Bromides]]

[[Category: ]]