Editing Tin(IV) chloride

{{chembox
| Verifiedfields = changed
| Watchedfields = changed
| verifiedrevid = 470610502
| ImageFileL1 = Tin(IV) chloride.jpg
| ImageCaptionL1 = Anhydrous Tin(IV) chloride 
| ImageNameL1 = Tin (IV) chloride
| ImageFileR1 = Tin(IV) chloride pentahydrate.jpg
| ImageCaptionR1 = Tin(IV) chloride pentahydrate
| ImageNameR1 = Tin(IV) chloride pentahydrate.jpg
| ImageFileL2 = Tin(IV)-chlorid.svg
| ImageFileR2 = SnCl4 OH2 2.svg
| IUPACName = Tetrachlorostannane<br/>Tin tetrachloride<br/>Tin(IV) chloride
| OtherNames = Stannic chloride
|Section1={{Chembox Identifiers
| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}
| ChemSpiderID = 22707
| InChI = 1/4ClH.Sn/h4*1H;/q;;;;+4/p-4
| InChIKey = HPGGPRDJHPYFRM-XBHQNQODAC
| SMILES = Cl[Sn](Cl)(Cl)Cl
| SMILES_Comment = anhydrous
| SMILES1 = Cl[Sn-2](Cl)(Cl)([OH2+])([OH2+])Cl.O.O.O
| SMILES1_Comment = pentahydrate
| StdInChI_Ref = {{stdinchicite|correct|chemspider}}
| StdInChI = 1S/4ClH.Sn/h4*1H;/q;;;;+4/p-4
| StdInChIKey_Ref = {{stdinchicite|correct|chemspider}}
| StdInChIKey = HPGGPRDJHPYFRM-UHFFFAOYSA-J
| CASNo = 7646-78-8
| CASNo_Ref = {{cascite|correct|CAS}}
| CASNo2_Ref = {{cascite|changed|??}}
| CASNo2 = 10026-06-9
| CASNo2_Comment = (pentahydrate)
| UNII_Ref = {{fdacite|correct|FDA}}
| UNII = 67H76LFL3V
| EINECS = 231-588-9
| RTECS = XP8750000
| UNNumber = 1827
| PubChem = 24287
  }}
|Section2={{Chembox Properties
| Formula = SnCl<sub>4</sub>
| MolarMass = 260.50 g/mol (anhydrous) <br> 350.60 g/mol (pentahydrate)
| Appearance = Colorless fuming liquid
| Odor = Acrid
| Density = 2.226 g/cm<sup>3</sup> (anhydrous) <br> 2.04 g/cm<sup>3</sup> (pentahydrate)
| Solubility = hydrolysis, very hygroscopic (anhydrous) <br> very soluble (pentahydrate)
| SolubleOther = soluble in [[ethanol|alcohol]], [[benzene]], [[toluene]], [[chloroform]], [[acetone]], [[kerosene]], [[carbon tetrachloride|CCl<sub>4</sub>]], [[methanol]], [[gasoline]], [[carbon disulfide|CS<sub>2</sub>]]
| MeltingPtC = -34.07
| MeltingPt_notes = (anhydrous) <br/> {{convert|56|C|F K}} (pentahydrate)
| BoilingPtC = 114.15
| Viscosity = 
| RefractIndex = 1.512
| VaporPressure = 2.4 kPa
| MagSus = &minus;115·10<sup>−6</sup> cm<sup>3</sup>/mol
  }}
|Section3={{Chembox Structure
| CrystalStruct = monoclinic (P21/c)
  }}
|Section4={{Chembox Thermochemistry
| DeltaHf = 
| Entropy = 
  }}
|Section7={{Chembox Hazards
| ExternalSDS = [http://www.inchem.org/documents/icsc/icsc/eics0953.htm ICSC 0953]
| NFPA-H = 3
| NFPA-F = 0
| NFPA-R = 1
| GHSPictograms = {{GHS05}}
| GHSSignalWord = Danger
| HPhrases = {{H-phrases|314|412}}
| PPhrases = {{P-phrases|260|264|273|280|301+330+331|303+361+353|304+340|305+351+338|310|321|363|405|501}}
  }}
|Section8={{Chembox Related
| OtherAnions = [[Tin(IV) fluoride]]<br/>[[Tin(IV) bromide]]<br/>[[Tin(IV) iodide]]
| OtherCations = [[Carbon tetrachloride]]<br/>[[Silicon tetrachloride]]<br/>[[Germanium tetrachloride]]<br/>[[Lead(IV) chloride]]
| OtherCompounds = [[Tin(II) chloride]]
  }}
}}

'''Tin(IV) chloride''', also known as '''tin tetrachloride''' or '''stannic chloride''', is an [[inorganic compound]] of [[tin]] and [[chlorine]] with the formula SnCl<sub>4</sub>. It is a colorless [[Hygroscopy|hygroscopic]] [[liquid]], which fumes on contact with air. It is used as a precursor to other tin compounds.<ref name = "Wiberg&Holleman">{{Cite book | author = Egon Wiberg, Nils Wiberg, Arnold Frederick Holleman | date = 2001 | title = Inorganic Chemistry | publisher = Elsevier | isbn = 0-12-352651-5}}</ref> It was first discovered by [[Andreas Libavius]] (1550–1616) and was known as ''spiritus fumans libavii''.

==Preparation==
It is prepared from reaction of chlorine gas with tin at {{convert|115|C|F}}:
:{{chem2|Sn + 2Cl2 → SnCl4}}

==Structure==
[[File:Tin(IV) chloride space-filling3D.png|alt=Space-filling model of anhydrous SnCl4.|left|thumb|151x151px|Space-filling model of anhydrous SnCl<sub>4</sub>.]]
[[File:SnCl4-xtal-down-b-axis-2005-CM-3D-polyhedra.png|200px|left|thumb|Structure of solid SnCl<sub>4</sub>.]]
Anhydrous tin(IV) chloride solidifies at −33&nbsp;°C to give [[monoclinic]] crystals with the P21/c [[space group]]. It is isostructural with [[SnBr4|SnBr<sub>4</sub>]]. The molecules adopt near-perfect tetrahedral symmetry with average Sn–Cl distances of 227.9(3) pm.<ref>{{cite journal |last=Reuter |first=Hans |author2=Pawlak, Rüdiger |title=Die Molekül- und Kristallstruktur von Zinn(IV)-chlorid |journal=Zeitschrift für anorganische und allgemeine Chemie |date=April 2000 |volume=626 |issue=4 |pages=925–929 |doi=10.1002/(SICI)1521-3749(200004)626:4<925::AID-ZAAC925>3.0.CO;2-R |language=German}}</ref>

==Reactions==
Tin(IV) chloride is well known as a [[Lewis acid]]. Thus it forms hydrates. The pentahydrate SnCl<sub>4</sub>·5H<sub>2</sub>O was formerly known as '''butter of tin'''. These hydrates consist of ''cis''-[SnCl<sub>4</sub>(H<sub>2</sub>O)<sub>2</sub>] molecules together with varying amounts of [[water of crystallization]]. The [[water of crystallization|additional water molecules]] link together the molecules of [SnCl<sub>4</sub>(H<sub>2</sub>O)<sub>2</sub>] through [[hydrogen bond]]s. A pentahydrate has also been crystallized.  In ''cis''-{{chem2|SnCl4(H2O)2*3H2O}}, the Sn-Cl bonds are 238.3 pm.<ref>{{cite journal |doi=10.1039/dt9800000949 |title=Crystal Structures of di-µ-Hydroxo-bis&#91;aquatrichlorotin (IV)&#93;–1,4-dioxan (1/3), di-µ-hydroxo-bis&#91;aquatrichlorotin(IV)&#93;–1,8-epoxy-p-menthane (1/4), di-µ-hydroxo-bis&#91;aquatribromotin (IV)&#93;–1,8-epoxy-p-menthane (1/4), di-µ-hydroxo-bis&#91;aquatrichlorotin(IV)&#93;–water (1/4), and ''cis''-Diaquatetrachlorotin (IV)–water (1/3) |date=1980 |last1=Barnes |first1=John C. |last2=Sampson |first2=Hazel A. |last3=Weakley |first3=Timothy J. R. |journal=J. Chem. Soc., Dalton Trans. |issue=6 |pages=949–953 }}</ref> Although the pentahydrate is the most common hydrate, lower hydrates have also been characterised.<ref>{{cite journal |last=Genge |first=Anthony R. J. |author2=Levason, William |author3=Patel, Rina |author4=Reid, Gillian |author5= Webster, Michael |display-authors=3 |title=Hydrates of tin tetrachloride |journal=[[Acta Crystallographica#Acta Crystallographica Section C: Structural Chemistry|Acta Crystallographica Section C]] |date=2004 |volume=60 |issue=4 |pages=i47–i49 |doi=10.1107/S0108270104005633 |pmid=15071197 |doi-access=free}}</ref>

Aside from water, other Lewis bases form adducts with SnCl<sub>4</sub>. These include [[ammonia]] and organo[[phosphine]]s.

The ammonium salt of [SnCl<sub>6</sub>]<sup>2−</sup> is formed from [[ammonium chloride]].  It is called "pink salt":<ref name=Ullmann/>
:{{chem2|SnCl4  +  2 (NH4)Cl → (NH4)2SnCl6}}
The analogous reaction with hydrochloric acid gives "hexachlorostannic acid".<ref name = "Wiberg&Holleman"/>

Reaction of the tetrachloride with [[hydrogen fluoride]] gives [[tin tetrafluoride]]:<ref name=Ullmann/>
:{{chem2|SnCl4  +  4 HF→ SnF4  +  4 HCl}}

Tin(IV) chloride undergoes [[redistribution reaction|redistribution]] with tin(IV) bromide as assessed by <sup>119</sup>Sn NMR and [[Raman spectroscopy]]. Equilibrium is achieved in seconds at room temperature.  By contrast, halide exchange for related germanium and especially silicon halides is slower.<ref>{{cite journal |doi=10.1021/cr60233a004 |title=Redistribution and Exchange Reactions in Groups IIB-VIIB |date=1965 |last1=Lockhart |first1=J. C. |journal=Chemical Reviews |volume=65 |pages=131–151 }}</ref>

==Applications==
===Precursor to organotin compounds===
Anhydrous tin(IV) chloride is a major precursor in [[organotin chemistry]]. Upon treatment with [[Grignard reagent]]s, tin(IV) chloride gives tetraalkyltin compounds:<ref name = "Greenwood">{{Greenwood&Earnshaw}}</ref>
:SnCl<sub>4</sub> + 4 RMgCl → SnR<sub>4</sub> + 4 MgCl<sub>2</sub>
Anhydrous tin(IV) chloride reacts with tetraorganotin compounds in [[redistribution reaction]]s:
:SnCl<sub>4</sub> + SnR<sub>4</sub> → 2 SnCl<sub>2</sub>R<sub>2</sub>
These organotin halides are useful precursors to catalysts (e.g., [[dibutyltin dilaurate]]) and polymer stabilizers.<ref name=Ullmann>G. G. Graf "Tin, Tin Alloys, and Tin Compounds" in Ullmann's Encyclopedia of Industrial Chemistry, 2005 Wiley-VCH, Weinheim. {{doi|10.1002/14356007.a27_049}}</ref>

===Organic synthesis===
SnCl<sub>4</sub> is used in [[Friedel–Crafts reaction]]s as a Lewis acid [[catalyst]].<ref name = "Wiberg&Holleman"/> For example, the acetylation of thiophene to give [[2-Acetylthiophene|2-acetylthiophene]] is promoted by tin(IV) chloride.<ref>{{cite journal |author=John R. Johnson, G. E. May|doi=10.15227/orgsyn.018.0001|title=2-Acetothienone|journal=Organic Syntheses|year=1938|volume=18|page=1}}</ref> Similarly, tin(IV) chloride is useful for nitrations.<ref>{{cite journal | journal = [[Synthesis (journal)|Synthesis]] | year = 1990 | pages = 81&ndash;84 | doi = 10.1055/s-1990-26795 | title = ''O''-Debenzylation of a Pyrrolo[2,1-''c''][1,4]benzodiazepine in the Presence of a Carbinolamine Functionality: Synthesis of DC-81 | author = Thurston, David E. | volume = 1990 | last2 = Murty | first2 = Varanasi S. | last3 = Langley | first3 = David R. | last4 = Jones | first4 = Gary B.| s2cid = 98109571 }}</ref>

==Safety==
Stannic chloride was used as a [[chemical weapon]] in [[World War I]], as it formed an irritating (but non-deadly) dense smoke on contact with air. It was supplanted by a mixture of [[silicon tetrachloride]] and [[titanium tetrachloride]] near the end of the war due to shortages of tin.<ref>{{Cite book | pages = 148–49, 407 | title = Chemical Warfare | first = Amos A. | last = Fries | publisher = Read | year = 2008 | isbn = 978-1-4437-3840-8 }}.</ref>

==References==
{{reflist}}

==External links==
{{Commons category|Tin(IV) chloride}}
* [https://www.inchem.org/documents/icsc/icsc/eics0953.htm International Chemical Safety Card 0953]
* {{Webarchive |url=https://web.archive.org/web/20050228231850/http://www.tinchemical.com/products.html |date=2005-02-28 |title=tinchemical.com/products (industrial uses) |nolink=1}}

{{Tin compounds}}
{{Chlorides}}

[[Category:Chlorides]]
[[Category:Tin(IV) compounds]]
[[Category:Metal halides]]