View source for Chemistry:Thorium(IV) bromide

{{Chembox
| Name = 
| ImageFile = 
|  ImageSize = 
|  ImageAlt = 
| IUPACName = 
| Section1 = {{Chembox Identifiers
|   CASNo = 13453-49-1
|   CASNo_Ref = {{cascite|correct|CAS}}
|   CASNo_Comment = anhydrous
|   CASNo2 = 20333-47-5
|   CASNo2_Ref = {{cascite|correct|CAS}}
|   CASNo2_Comment = octahydrate
| ChemSpiderID = 75321
| EC_number = 236-628-9
|   PubChem = 83483
| StdInChI=1S/4BrH.Th/h4*1H;/q;;;;+4/p-4
| StdInChIKey = OMDXFCRSKHYDTM-UHFFFAOYSA-J
|   SMILES =  Br[Th](Br)(Br)Br}}
| Section2 = {{Chembox Properties
|   Formula = ThBr<sub>4</sub>
|   MolarMass = 551.65
|   Appearance = white solid
|   Density = 5.72 g·cm<sup>−3</sup> (α)<br>5.76 g·cm<sup>−3</sup> (β)
|   MeltingPt = 678±5 °C<ref>{{cite journal|journal=Journal of the Less Common Metals|volume=35|issue=2|language=en|date=April 1974|pages=331–338|doi=10.1016/0022-5088(74)90245-8|url=https://linkinghub.elsevier.com/retrieve/pii/0022508874902458|title=Crystal structures of ThBr4 polymorphs|accessdate=2020-11-03|first1=J.T. |last1=Mason |first2=M.C. |last2=Jha |first3=D.M. |last3=Bailey |first4=P. |last4=Chiotti|archive-date=2018-07-01|archive-url=https://web.archive.org/web/20180701212731/https://linkinghub.elsevier.com/retrieve/pii/0022508874902458|url-status=live}}</ref>
|   BoilingPt = 
|   Solubility =  soluble}}
| Section3 = {{Chembox Hazards
|   MainHazards = 
|   FlashPt = 
|   Autoignition =  }}
}}

'''Thorium(IV) bromide''' is an inorganic compound, with the chemical formula of ThBr<sub>4</sub>.

== Preparation ==

Thorium(IV) bromide can be obtained by reacting [[Chemistry:Thorium dioxide|thorium dioxide]], [[Chemistry:Bromine|bromine]] and [[Chemistry:Carbon|carbon]] at 800~900&nbsp;°C. This method produces a mixture of alpha and beta forms of thorium bromide. The pure α-form product is obtained by heating the mixture at 330~375&nbsp;°C for a long time. The pure β form is obtained by heating the product to 470&nbsp;°C and then rapidly cooling it in ice water.<ref name=Georg>Georg Brauer, unter Mitarbeit von Marianne Baudler u. a. (Hrsg.): Handbuch der Präparativen Anorganischen Chemie. 3., umgearbeitete Auflage. Band I. Ferdinand Enke, Stuttgart 1975, ISBN 3-432-02328-6, S. 1136.</ref>

:{{chem2|ThO2 + 2 C + 2 Br2 ⟶ ThBr4 + 2 CO}}

Thorium(IV) bromide can also be produced by the reaction of [[Chemistry:Thorium|thorium]] and bromine. Thorium hydroxide reacts with [[Chemistry:Hydrobromic acid|hydrobromic acid]] to crystallize hydrates from the solution.<ref name=Lester>{{Cite book |last1=Morss |first1=L. R. |url=https://books.google.com/books?id=9vPuV3A0UGUC&pg=PA81 |title=The Chemistry of the Actinide and Transactinide Elements (Set Vol.1-6): Volumes 1-6 |last2=Edelstein |first2=Norman M. |last3=Fuger |first3=Jean |date=2010-10-21 |publisher=Springer Science & Business Media |isbn=978-94-007-0211-0 |language=en}}</ref>

== Properties ==

Thorium(IV) bromide exists in low-temperature α-type and high-temperature β-type. They are both white deliquescent solids and are easily soluble in water, [[Chemistry:Ethanol|ethanol]] and [[Chemistry:Ethyl acetate|ethyl acetate]]. It reacts with [[Chemistry:Fluorine|fluorine]] gas under standard conditions and with [[Chemistry:Chlorine|chlorine]] or [[Chemistry:Oxygen|oxygen]] when heated. The beta form of thorium bromide is metastable at room temperature and converts to the alpha form over 10 to 12 weeks, with the conversion from alpha to beta occurring at around 420&nbsp;°C. The α-type thorium(IV) bromide is an orthorhombic crystal, while the β-type thorium(IV) bromide is a tetragonal crystal with [[Space group|space group]] ''I''4<sub>1</sub>/amd. Some of its hydrates are known, and these hydrates form thorium oxybromide on heating.<ref name=Lester />

== References ==
{{reflist}}

==External reading==
* {{Cite journal |last1=Mikheev |first1=N. B. |last2=Kamenskaya |first2=A. N. |last3=Kulyukhin |first3=S. A. |last4=Rumer |first4=I. A. |last5=Novichenko |first5=V. L. |date=2001 |title=Sorption of CH3131I from the Gas Phase on Modified Metal-Substituted Zeolites Containing Copper and Silver Ions |url=http://dx.doi.org/10.1023/a:1012868726987 |journal=Radiochemistry |volume=43 |issue=3 |pages=293–296 |doi=10.1023/a:1012868726987 |s2cid=92635246 |issn=1066-3622}}

{{Thorium compounds}}

[[Category:Bromides]]
[[Category:Actinide halides]]

{{Sourceattribution|Thorium(IV) bromide}}