Editing Tin(IV) chloride (section)

==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>