Editing Tin (section)

==Compounds and chemistry==
{{category see also|Tin compounds}}
In the great majority of its compounds, tin has the [[oxidation state]] II or IV. Compounds containing [[Bivalent (chemistry)|bivalent]] tin are called {{em|[[:wiktionary:stannous|{{visible anchor|stannous}}]]}} while those containing [[tetravalent]] tin are termed {{em|[[:wiktionary:stannic|{{visible anchor|stannic}}]]}}.

===Inorganic compounds===
[[Halide]] compounds are known for both oxidation states. For Sn(IV), all four halides are well known: [[Tin(IV) fluoride|SnF<sub>4</sub>]], [[Tin(IV) chloride|SnCl<sub>4</sub>]], [[Tin(IV) bromide|SnBr<sub>4</sub>]], and [[Tin(IV) iodide|SnI<sub>4</sub>]]. The three heavier members are volatile molecular compounds, whereas the tetrafluoride is polymeric. All four halides are known for Sn(II) also: [[Tin(II) fluoride|SnF<sub>2</sub>]], [[Tin(II) chloride|{{chem|SnCl|2}}]], [[Tin(II) bromide|SnBr<sub>2</sub>]], and [[Tin(II) iodide|SnI<sub>2</sub>]]. All are polymeric solids. Of these eight compounds, only the iodides are colored.<ref name = "Wiberg&Holleman">{{Holleman&Wiberg}}</ref>

[[Tin(II) chloride]] (also known as stannous chloride) is the most important commercial tin halide. Illustrating the routes to such compounds, [[chlorine]] reacts with tin metal to give SnCl<sub>4</sub> whereas the reaction of [[hydrochloric acid]] and tin produces {{chem|SnCl|2}} and hydrogen gas. Alternatively SnCl<sub>4</sub> and Sn combine to stannous chloride by a process called [[comproportionation]]:<ref>{{Greenwood&Earnshaw2nd}}{{page needed|date=June 2021}}</ref>
:SnCl<sub>4</sub> + Sn → 2 {{chem|SnCl|2}}

Tin can form many oxides, sulfides, and other [[chalcogenide]] derivatives. The dioxide {{chem|SnO|2}} (cassiterite) forms when tin is heated in the presence of [[air]].<ref name="Wiberg&Holleman" /> {{chem|SnO|2}} is [[amphoteric]], which means that it dissolves in both acidic and basic solutions.<ref name = "Sherwood">{{cite book| title= Inorganic & Theoretical Chemistry| first= F. Sherwood |last= Taylor| publisher= Heineman| edition= 6th |year= 1942}}</ref> Stannates with the structure [{{chem|Sn(OH)|6}}]<sup>2−</sup>, like {{chem|K|2}}[{{chem|Sn(OH)|6}}], are also known, though the free stannic acid {{chem|H|2}}[{{chem|Sn(OH)|6}}] is unknown.{{Citation needed|date=August 2024}}

[[Sulfide]]s of tin exist in both the +2 and +4 oxidation states: [[tin(II) sulfide]] and [[tin(IV) sulfide]] ([[mosaic gold]]).
[[File:Tin(II)-chloride-xtal-1996-3D-balls-front.png|thumb|[[Ball-and-stick model]]s of the structure of solid [[stannous chloride]] ({{chem|SnCl|2}})<ref>{{cite journal |journal = J. Phys. Chem. Solids|volume = 57|issue = 1|date = 1996|pages = 7–16|title = The high pressure behaviour of the cotunnite and post-cotunnite phases of PbCl<sub>2</sub> and {{chem|SnCl|2}} |author = Leger, J. M. |author2 = Haines, J. |author3 = Atouf, A. |doi = 10.1016/0022-3697(95)00060-7|bibcode = 1996JPCS...57....7L }}</ref>]]

===Hydrides===
[[Stannane]] ({{chem|SnH|4}}), with tin in the +4 oxidation state, is unstable. Organotin hydrides are however well known, e.g. [[tributyltin hydride]] (Sn(C<sub>4</sub>H<sub>9</sub>)<sub>3</sub>H).<ref name="Hol1985" /> These compounds release transient [[Tributyltin|tributyl tin]] radicals, which are rare examples of compounds of tin(III).<ref>{{cite journal | doi = 10.1002/zaac.19733980109 | title = Organic Derivatives of Tin. III. Reactions of Trialkyltin Ethoxide with Alkanolamines | date = 1973 | last1 = Gaur | first1 = D. P.| last2 = Srivastava | first2 = G. | last3 = Mehrotra | first3 = R. C.| journal = Zeitschrift für Anorganische und Allgemeine Chemie | volume = 398 | page = 72}}</ref>

===Organotin compounds===
[[Organotin]] compounds, sometimes called stannanes, are [[chemical compounds]] with tin–carbon bonds.<ref>{{Cite book|last=Elschenbroich|first=Christoph|url=https://www.worldcat.org/oclc/64305455|title=Organometallics.|date=2006|publisher=Wiley-VCH|isbn=3-527-29390-6|edition=3rd, completely rev. and extended|location=Weinheim|oclc=64305455}}</ref> Of the tin compounds, the organic derivatives are commercially the most useful.<ref name="Ullmann" /> Some organotin compounds are highly toxic and have been used as [[biocide]]s. The first organotin compound to be reported was diethyltin diiodide ((C<sub>2</sub>H<sub>5</sub>)<sub>2</sub>SnI<sub>2</sub>), reported by [[Edward Frankland]] in 1849.<ref>{{cite journal|title = Synthetic aspects of tetraorganotins and organotin(IV) halides| first1= Sander H. L.| last1= Thoonen |first2 = Berth-Jan| last2= Deelman| first3 = Gerard |last3= van Koten|journal = [[Journal of Organometallic Chemistry]] |issue = 13|date = 2004| volume= 689|pages = 2145–2157| doi= 10.1016/j.jorganchem.2004.03.027| hdl= 1874/6594| s2cid= 100214292|url = http://igitur-archive.library.uu.nl/chem/2005-0622-182223/13093.pdf |url-status = dead|archive-url = https://web.archive.org/web/20110807042719/http://igitur-archive.library.uu.nl/chem/2005-0622-182223/13093.pdf| archive-date = 2011-08-07|access-date = 2009-07-31}}</ref>

Most organotin compounds are colorless liquids or solids that are stable to air and water. They adopt tetrahedral geometry. Tetraalkyl- and tetraaryltin compounds can be prepared using [[Grignard reagent]]s:<ref name="Ullmann" />
:{{chem|SnCl|4}} + 4 RMgBr → {{chem|R|4|Sn}} + 4 MgBrCl
The mixed halide-alkyls, which are more common and more important commercially than the tetraorgano derivatives, are prepared by [[redistribution reaction]]s:
:{{chem|SnCl|4}} + {{chem|R|4|Sn}} → 2 {{chem|SnCl|2}}R<sub>2</sub>

Divalent organotin compounds are uncommon, although more common than related divalent [[organogermanium]] and [[organosilicon]] compounds. The greater stabilization enjoyed by Sn(II) is attributed to the "[[inert pair effect]]". Organotin(II) compounds include both stannylenes (formula: R<sub>2</sub>Sn, as seen for singlet [[carbene]]s) and distannylenes (R<sub>4</sub>Sn<sub>2</sub>), which are roughly equivalent to [[alkene]]s. Both classes exhibit unusual reactions.<ref>{{cite journal | last1 = Peng | first1 = Yang | last2 = Ellis | first2 = Bobby D. | last3 = Wang | first3 = Xinping | last4 = Fettinger | first4 = James C. | last5 = Power | first5 = P. P.| date = 2009| title = Reversible Reactions of Ethylene with Distannynes Under Ambient Conditions |journal = Science | volume = 325| pages = 1668–1670 | doi = 10.1126/science.1176443 |bibcode = 2009Sci...325.1668P | issue = 5948 | pmid = 19779193 | s2cid = 3011002 }}</ref>