{{Short description|Organometallic compound containing carbon–silicon bonds}} [[File:PmdsStructure.svg|thumb|right|Polydimethylsiloxane (PDMS) is the principal component of silicones.]] '''Organosilicon chemistry''' is the study of organometallic compounds containing carbon–silicon bonds, to which they are called '''organosilicon compounds'''. Most organosilicon compounds are similar to the ordinary organic compounds, being colourless, flammable, hydrophobic, and stable to air.

However, silicon carbide is considered an ''inorganic'' compound.

== History == {{See also|Organometallic chemistry}} In 1863, Charles Friedel and James Crafts made the first organochlorosilane compound<!--what was it?-->.<ref name=":1">{{Cite journal |last=Muller |first=Richard |date=January 1965 |title=One hundred years of organosilicon chemistry |url=https://pubs.acs.org/doi/abs/10.1021/ed042p41 |journal=Journal of Chemical Education |language=en |volume=42 |issue=1 |pages=41 |doi=10.1021/ed042p41 |bibcode=1965JChEd..42...41M |issn=0021-9584|url-access=subscription }}</ref> The same year, they also described a "polysilicic acid ether" in the preparation of ethyl- and methyl-o-silicic acid.<ref name=":1" /> Extensive research in the field of organosilicon compounds was pioneered in the beginning of 20th century by Frederic S. Kipping.<ref name=":0">{{Cite journal |last=Thomas |first=Neil R. |date=October 2010 |title=Frederic Stanley Kipping—Pioneer in Silicon Chemistry: His Life & Legacy |journal=Silicon |language=en |volume=2 |issue=4 |pages=187–193 |doi=10.1007/s12633-010-9051-x |issn=1876-990X|doi-access=free }}</ref> He also had coined the term "silicone" (resembling ''ketones'', though this is erroneous)<ref>{{Cite journal |last=Kipping |first=Frederic Stanley |date=1912-01-01 |title=CCXXII.—Organic derivatives of silicon. Part XV. The nomenclature of organic silicon compounds |url=https://pubs.rsc.org/en/content/articlelanding/1912/ct/ct9120102106 |journal=Journal of the Chemical Society, Transactions |language=en |volume=101 |pages=2106–2107 |doi=10.1039/CT9120102106 |issn=0368-1645|url-access=subscription }}</ref><ref>{{Cite book |title=Handbook of detergents. Part F, Production |date=2009 |publisher=CRC Press |others=Uri Tsoler, Paul Sosis |isbn=978-1-4200-1465-5 |location=Boca Raton, FL |oclc=319710487}}</ref>{{Rp|page=286}} in relation to these materials in 1904. In recognition of Kipping's achievements, the Dow Chemical Company had established an award in the 1960s that is given for significant contributions to the field of silicon chemistry.<ref>{{Cite web |title=Frederic Stanley Kipping Award in Silicon Chemistry |url=https://www.acs.org/funding/awards/frederic-stanley-kipping-award-in-silicon-chemistry.html |access-date=2022-12-22 |website=American Chemical Society |language=en}}</ref> In his works, Kipping was noted for using Grignard reagents to make alkyl<nowiki/>silanes and aryl<nowiki/>silanes and preparing silicone oligomers and polymers for the first time.<ref name=":0" />

In 1945, Eugene G. Rochow also made a significant contribution to the field of organosilicon chemistry by first describing the Müller-Rochow process.<ref>{{Cite journal |last=Rochow |first=Eugene G. |date=June 1945 |title=The Direct Synthesis of Organosilicon Compounds |url=https://pubs.acs.org/doi/abs/10.1021/ja01222a026 |journal=Journal of the American Chemical Society |language=en |volume=67 |issue=6 |pages=963–965 |doi=10.1021/ja01222a026 |bibcode=1945JAChS..67..963R |issn=0002-7863|url-access=subscription }}</ref>

==Occurrence and applications== thumb|right|Silicone caulk, commercial sealants, are mainly composed of organosilicon compounds mixed with hardener. Organosilicon compounds are widely encountered in commercial products. Most common are antifoamers, caulks (sealant), adhesives, and coatings made from silicones. Other important uses include agricultural and plant control adjuvants commonly used in conjunction with herbicides and fungicides.<ref name="sciencedirect.com">{{cite journal|date=2017 |title=Synthesis, characterization and thermal properties of T8 type amido-POSS with p-halophenyl end-group|journal=Journal of Organometallic Chemistry |volume=847|pages=173–183|doi=10.1016/j.jorganchem.2017.05.044|last1=Janeta|first1=Mateusz|last2=Szafert|first2=Sławomir}}</ref>

===Biology and medicine=== Carbon–silicon bonds are absent in biology, however enzymes have been used to artificially create carbon-silicon bonds in living microbes.<ref>{{cite web |last1=Choi |first1=Charles |title=Possibility Of Silicon Based Life Grows |url=https://www.astrobio.net/news-exclusive/possibility-silicon-based-life-grows/ |website=Astrobiology Magazine |access-date=28 October 2019 |url-status=usurped |archive-url=https://web.archive.org/web/20170821224515/http://www.astrobio.net/news-exclusive/possibility-silicon-based-life-grows/ |archive-date=2017-08-21}}</ref><ref>{{cite journal |first1=Mark B. |last1=Frampton |first2=Paul M. |last2=Zelisko |title=Organosilicon Biotechnology |journal=Silicon |volume=1 |issue= 3|pages=147–163 |date=2009 |doi=10.1007/s12633-009-9021-3 |s2cid=195219283 }}</ref><ref name=PSurvey>{{cite book |first=S. |last=Pawlenko |title=Organosilicon Chemistry |publisher=de Gruyter |date=2011 |orig-date=1986 |isbn=978-3-11-086238-6 |page=7 |url={{GBurl|T14gnsL4sr4C|pg=PR7}}}}</ref> Silicates, on the other hand, have known existence in diatoms.<ref name="kin2002">{{cite journal |first1=Stephen D. |last1=Kinrade |first2=Ashley-M. E. |last2=Gillson |first3=Christopher T. G. |last3=Knight |title=Silicon-29 NMR evidence of a transient hexavalent silicon complex in the diatom ''Navicula pelliculosa'' |journal=J. Chem. Soc., Dalton Trans. |volume= |issue= 3|pages=307–9 |date=2002 |doi=10.1039/b105379p }}</ref> Silafluofen is an organosilicon compound that functions as a pyrethroid insecticide. Several organosilicon compounds have been investigated as pharmaceuticals.<ref>{{cite journal |last1=Bains |first1=W. |last2=Tacke |first2=R. |title=Silicon chemistry as a novel source of chemical diversity in drug design |journal=Curr. Opin. Drug Discov. Dev. |volume=6 |issue=4 |pages=526–543 |date=2003 |doi= |pmid=12951816}}</ref><ref name="phys.org">{{Cite web|url=https://phys.org/news/2017-01-common-crop-chemical-bees-susceptible.html#ms|title=Common crop chemical leaves bees susceptible to deadly viruses |date=2017 |publisher=Phys.org}}</ref>

==Bonding== {| class="wikitable sortable floatleft" |+ Bonds relevant to organosilicon chemistry |- ! Bond !! Bond length<br>(pm) !! Approx. bond<br /> strength (kJ/mol) |- | C–C || 154 || 334 |- | Si–Si || 234 || 196 |- | C–Si || 186 || 314 |- | C–H || 110 || 414 |- | Si–H || 146 || 314 |- | C–O || 145 || 355 |- | Si–O || 159 || 460 |- |}

{| class="wikitable sortable floatleft" |+ Dissociation energies of bonds to silicon<ref name=ZakData /> |- ! Bond !! Energy (kJ/mol) |- | Si–Si || 327(10) |- | Si–Br || 343(50) |- | Si–C || 435(21) |- | Si–Cl || 456(42) |- | Si–F || 540(13) |- | Si–H || 298.49(46) |- | Si–I || 339(84) |- | Si–N || 439(38) |- | Si–O || 798(8) |- | Si–S || 619(13) |- | Si–Se || 531(25) |- | H<sub>3</sub>Si–SiH<sub>3</sub> || 339(17) |- | Me<sub>3</sub>Si–SiMe<sub>3</sub> || 339 |- | Ar<sub>3</sub>Si–SiAr<sub>3</sub> || 368(31) |- | Si–Te || 506(38) |}

In the great majority of organosilicon compounds, Si is tetravalent with tetrahedral molecular geometry. Compared to carbon–carbon bonds, carbon–silicon bonds are longer and weaker.<ref name="sciencedirect.com"/><ref>{{cite book |title=Handbook of Chemistry and Physics |publisher=CRC Press |edition=81st |date= June 2000|isbn=0-8493-0481-4 |pages= }}</ref>

The C–Si bond is somewhat polarised towards carbon due to carbon's greater electronegativity (C 2.55 vs Si 1.90), and single bonds from Si to electronegative elements are very strong.<ref name=ZakData>{{cite web|title=Properties of atoms, radicals, and bonds|url=https://labs.chem.ucsb.edu/zakarian/armen/11---bonddissociationenergy.pdf|access-date=28 Nov 2022|publisher=Zakarian lab, UCSB}}</ref> Silicon is thus susceptible to nucleophilic attack by O<sup>−</sup>, Cl<sup>−</sup>, or F<sup>−</sup>; the energy of an Si–O bond in particular is strikingly high. This feature is exploited in many reactions such as the Sakurai reaction, the Brook rearrangement, the Fleming–Tamao oxidation, and the Peterson olefination.<ref>{{cite book |first=E. |last=Colvin |title=Silicon in Organic Synthesis |publisher=Butterworth |orig-date=1981 |date=2014 |isbn=978-1-4831-4223-4 |pages= |url={{GBurl|PDT9BAAAQBAJ|pg=PR9}}}}</ref>

The Si–C bond (1.89 Å) is significantly longer than a typical C–C bond (1.54 Å), suggesting that silyl substitutents have less steric demand than their organyl analogues. When geometry allows, silicon exhibits negative hyperconjugation, reversing the usual polarization on neighboring atoms.{{cn|date=November 2023}}

==Preparation== The first organosilicon compound, tetraethylsilane, was prepared by Charles Friedel and James Crafts in 1863 by reaction of tetrachlorosilane with diethylzinc.

Most organosilicon compounds derive from organosilicon chlorides {{chem|(CH|3|)|4−''x''|SiCl|''x''}}. These methyl chlorides are produced by the "Direct process", which entails the reaction of methyl chloride with a silicon-copper alloy. The main and most sought-after product is dimethyldichlorosilane:

:{{chem2|2 CH3Cl + Si -> (CH3)2SiCl2}}

A variety of other products are obtained, including trimethylsilyl chloride and methyltrichlorosilane. About 1 million tons of organosilicon compounds are prepared annually by this route. The method can also be used for phenyl chlorosilanes.<ref name=Roeshe>{{cite book |last1=Röshe |first1=L. |last2=John |first2=P. |last3=Reitmeier |first3=R. |chapter=Organic Silicon Compounds |chapter-url= |doi=10.1002/14356007.a24_021 |title=Ullmann's Encyclopedia of Industrial Chemistry |publisher=Wiley |date=2003 |isbn= |pages= }}</ref>

===Hydrosilylation=== {{Main|Hydrosilylation}}

Another major method for the formation of Si-C bonds is hydrosilylation (also called hydrosilation).<ref>{{cite book |chapter=Hydrosilylation |doi=10.1007/978-1-4020-8172-9_1 |editor-first=B. |editor-last=Marciniec |title=Advances in Silicon Science |publisher=Springer |date=2009 |volume=1 |isbn=978-1-4020-8172-9 |pages= 3–51}}</ref> In this process, compounds with Si–H bonds (hydrosilanes) are added to unsaturated substrates. Commercially, the main substrates are alkenes. Other unsaturated functional groups&nbsp;— alkynes, imines, ketones, and aldehydes&nbsp;— also participate, but these reactions are of little economic value.<ref>{{cite journal |last1=Ramírez-Oliva |first1=E. |last2=Hernández |first2=A. |last3=Martínez-Rosales |first3=J.M. |last4=Aguilar-Elguezabal |first4=A. |last5=Herrera-Pérez |first5=G. |last6=Cervantes |first6=J. |title=Effect of the synthetic method of Pt/MgO in the hydrosilylation of phenylacetylene |journal=Arkivoc |volume=126 |issue= |pages=136 |date=2006 |doi= |url=https://www.arkat-usa.org/ARKIVOC/JOURNAL_CONTENT/manuscripts/2006/EL-1973AP%20as%20published%20mainmanuscript.pdf}}</ref>

thumb|Idealized mechanism for metal-catalysed hydrosilylation of an alkene

Hydrosilylation requires metal catalysts, especially those based on platinum group metals. In the related silylmetalation, a metal replaces the hydrogen atom.

===Via cleavage of Si–Si bonds=== Hexamethyldisilane reacts with methyllithium to give trimethylsilyl lithium:<ref>{{cite book |doi=10.1002/047084289X.rt312.pub2|chapter=Trimethylsilyllithium |title=Encyclopedia of Reagents for Organic Synthesis |year=2009 |last1=Linderman |first1=Russell J. |last2=Stiasni |first2=Nikola |last3=Hiersemann |first3=Martin |isbn=978-0471936237 }}</ref> :{{chem2|(CH3)6Si2 + CH3Li -> (CH3)3SiLi + (CH3)4Si}} Similarly, tris(trimethylsilyl)silyl lithium is derived from tetrakis(trimethylsilyl)silane:<ref name=OS>{{cite journal|title=Tris(trimethylsilyl)silane|first1=Joachim |last1=Dickhaut |first2=Bernd |last2=Giese|journal=Org. Synth.|year=1992|volume=70|page=164|doi=10.15227/orgsyn.070.0164}}</ref> :{{chem2|((CH3)3Si)4Si + CH3Li → ((CH3)3Si)3SiLi + (CH3)4Si}}

== Functional groups == Silicon is a component of many functional groups. Most of these are analogous to organic compounds. The overarching exception is the rarity of multiple bonds to silicon, as reflected in the double bond rule.

=== Silanols, siloxides, siloxanes, and silazanes === Silanols are analogues of alcohols. They are generally prepared by hydrolysis of silyl chlorides:<ref name=Lickiss/> :{{chem|R|3|SiCl}} + {{H2O}} → {{chem|R|3|SiOH}} + HCl Less frequently silanols are prepared by oxidation of silyl hydrides, a reaction that uses a metal catalyst: :2 {{chem|R|3|SiH}} + {{chem|O|2}} → 2 {{chem|R|3|SiOH}}

Many silanols have been isolated including {{chem|link=trimethylsilanol|(CH|3|)|3|SiOH}} and {{chem|(C|6|H|5|)|3|SiOH}}. They are about 500x more acidic than the corresponding alcohols. Siloxides are the deprotonated derivatives of silanols:<ref name=Lickiss>{{cite journal |first=Paul D. |last=Lickiss |title=The Synthesis and Structure of Organosilanols |journal=Advances in Inorganic Chemistry |volume=42 |issue= |pages=147–262 |date=1995 |doi=10.1016/S0898-8838(08)60053-7 |isbn=9780120236428 }}</ref> :{{chem|R|3|SiOH}} + NaOH → {{chem|R|3|SiONa}} + {{H2O}}

Silanols tend to dehydrate to give siloxanes: :2 {{chem|R|3|SiOH}} → {{chem|R|3|Si-O-SiR|3}} + {{H2O}} Polymers with repeating siloxane linkages are called silicones. Compounds with an Si=O double bond called silanones are extremely unstable.

Analogous compounds with nitrogen instead of oxygen are the silazanes.

===Silyl ethers=== Silyl ethers have the connectivity Si–O–C. They are typically prepared by the reaction of alcohols with silyl chlorides:

:{{chem2|(CH3)3SiCl + ROH -> (CH3)3Si\sO\sR + HCl}}

Silyl ethers are extensively used as protective groups for alcohols.

Exploiting the strength of the Si–F bond, fluoride sources such as tetra-n-butylammonium fluoride (TBAF) are used in deprotection of silyl ethers:

:{{chem2|(CH3)3Si\sO\sR + F− + H2O -> (CH3)3Si\sF + H\sO\sR + OH−}}

===Silyl chlorides=== {{main|Chlorosilane}}

Organosilyl chlorides are important commodity chemicals. They are mainly used to produce silicone polymers as described above. Especially important silyl chlorides dimethyldichlorosilane ({{chem|Me|2|SiCl|2}}), methyltrichlorosilane ({{chem|MeSiCl|3}}), and trimethylsilyl chloride ({{chem|Me|3|SiCl}}) are all produced by direct process. More specialized derivatives that find commercial applications include dichloromethylphenylsilane, trichloro(chloromethyl)silane, trichloro(dichlorophenyl)silane, trichloroethylsilane, and phenyltrichlorosilane.

Although proportionately a minor outlet, organosilicon compounds are widely used in organic synthesis. Notably trimethylsilyl chloride {{chem|Me|3|SiCl}} is the main silylating agent. One classic method called the '''Flood reaction''' for the synthesis of this compound class is by heating hexaalkyldisiloxanes {{chem|R|3|SiOSiR|3}} with concentrated sulfuric acid and a sodium halide.<ref>{{cite journal |first=E.A. |last=Flood |title=Preparation of Triethylsilicon Halides |journal=J. Am. Chem. Soc. |volume=55 |issue=4 |pages=1735–6 |date=1933 |doi=10.1021/ja01331a504 |bibcode=1933JAChS..55.1735F }}</ref>

===Silyl hydrides=== {{Main|Hydrosilane}}

[[File:TTMSS.svg|thumb|Tris(trimethylsilyl)silane is a well-investigated hydrosilane.<ref>{{cite journal|title=Thirty Years of (TMS)<sub>3</sub>SiH: A Milestone in Radical-Based Synthetic Chemistry|first1=Chryssostomos |last1=Chatgilialoglu |first2=Carla |last2=Ferreri |first3=Yannick |last3=Landais |first4=Vitaliy I. |last4=Timokhin|journal=Chemical Reviews|year=2018|volume=118|issue=14|pages=6516–72|doi=10.1021/acs.chemrev.8b00109|pmid=29938502|s2cid=49413857}}</ref>]] The silicon to hydrogen bond is longer than the C–H bond (148 compared to 105 pm) and weaker (299 compared to 338 kJ/mol). Hydrogen is more electronegative than silicon hence the naming convention of silyl ''hydrides''. Commonly the presence of the hydride is not mentioned in the name of the compound. Triethylsilane has the formula {{chem|Et|3|SiH}}. Phenylsilane is {{chem|PhSiH|3}}. The parent compound {{chem|SiH|4}} is called silane.

===Silylium ions=== Silylium ions have general formula [SiR{{prime|R}}R{{pprime}}]<sup>+</sup>. They are more stable in the gas phase than the corresponding carbocations, because silicon is more electropositive than carbon. However, silicon stabilizes higher coordination numbers than carbon, such that silylium ions are much less stable and more electrophilic in condensed phases.<ref name=AdamantogenRev/> Thus for example trimethylsilyl hydrogen sulfate is a covalent ester in sulfuric acid solution, rather than dissociated ions.<ref>{{cite book|p=167|title=Non-Aqueous Solvent Systems|editor-first=T.&nbsp;C.|editor-last=Waddington|chapter=Sulphuric Acid|first1=R.&nbsp;J.|last1=Gillespie|first2=E.&nbsp;A.|last2=Robinson|year=1965|publisher=Academic Press|location=London, UK|lccn=65-14294}}</ref>

Silylium ions can be isolated with noncoordinating solvents and anions. Typically, they are synthesized via hydride abstraction from a hydrosilane.<ref name=AdamantogenRev>{{cite book|via=ResearchGate|url=https://www.researchgate.net/publication/233842683|chapter=Silicon-, germanium-, and tin-centered cations, radicals, and anions|first1=Vladimir&nbsp;Ya.|last1=Lee|author2=Sekiguchi Akira|title=Reviews of Reactive Intermediate Chemistry|editor-first1=Matthew&nbsp;S.|editor-last1=Platz|editor-first2=Robert&nbsp;A.|editor-last2=Moss|editor-first3=Maitland|editor-last3=Jones|year=2007|publisher=Wiley|pages=49–51}}</ref>

===Silenes=== thumb|General formula of a Silenes Organosilicon compounds, unlike their carbon counterparts, do not have a rich double bond chemistry.<ref>{{cite journal |first1=Henrik |last1=Ottosson |first2=Patrick G. |last2=Steel |title=Silylenes, Silenes, and Disilenes: Novel Silicon-Based Reagents for Organic Synthesis? |journal=Chem. Eur. J. |volume=12 |issue= 6|pages=1576–85 |date=2006 |doi=10.1002/chem.200500429 |pmid=16138382 |url=https://durham-repository.worktribe.com/output/1546230 }}</ref> Compounds with '''silene''' Si=C bonds (also known as '''alkylidenesilanes''') are laboratory curiosities such as the silicon benzene analogue silabenzene. In 1967, Gusel'nikov and Flowers provided the first evidence for silenes from pyrolysis of ''dimethylsilacyclobutane''.<ref>{{cite journal |first1=L.E. |last1=Gusel'Nikov |first2=M.C. |last2=Flowers |title=The thermal decomposition of 1,1-dimethyl-1-silacyclobutane and some reactions of an unstable intermediate containing a silicon–carbon double bond |journal=Chem. Commun. |volume= |issue= 17|pages=864–5 |date=1967 |doi=10.1039/C19670000864 }}</ref> The first stable (kinetically shielded) silene was reported in 1981 by Brook.<ref>{{cite journal |first1=Adrian G. |last1=Brook |first2=Fereydon |last2=Abdesaken |first3=Brigitte |last3=Gutekunst |first4=Gerhard |last4=Gutekunst |first5=R. Krishna |last5=Kallury |title=A solid silaethene: isolation and characterization |journal=J. Chem. Soc., Chem. Commun. |volume= |issue= 4|pages=191–2 |date=1981 |doi=10.1039/C39810000191 }}</ref><ref>{{cite journal |first=Kim M. |last=Baines |title=Brook silenes: inspiration for a generation |journal=Chem. Commun. |volume= 49|issue= 57|pages=6366–9 |date=2013 |doi=10.1039/C3CC42595A |pmid=23752786 }}</ref>

:Silenes Gusel'nikov 1967 Brook 1981

Disilenes have Si=Si double bonds and disilynes are silicon analogues of an alkyne. The first '''silyne''' (with a silicon to carbon triple bond) was reported in 2010.<ref>{{cite journal |last1=Gau |first1=D. |last2=Kato |first2=T. |last3=Saffon-Merceron |first3=N. |last4=De Cózar |first4=A. |last5=Cossío |first5=F. |last6=Baceiredo |first6=A. |title=Synthesis and Structure of a Base-Stabilized C-Phosphino-Si-Amino Silyne |journal=Angewandte Chemie International Edition |volume=49 |issue= 37|pages=6585–8 |date=2010 |doi=10.1002/anie.201003616 |pmid=20677192 }}</ref>

===Siloles=== thumb|upright=.3|Chemical structure of silole '''Siloles''', also called '''silacyclopentadienes''', are members of a larger class of compounds called metalloles. They are the silicon analogs of cyclopentadienes and are of current academic interest due to their electroluminescence and other electronic properties.<ref>{{cite journal |first1=Nicholas A.|last1=Morra|first2=Brian L.|last2=Pagenkopf|title=Direct Synthesis of 2,5-dihalosiloles |journal=Organic Syntheses |volume=85 |issue= |pages=53–63 |date=2008 |doi= 10.15227/orgsyn.085.0053}}</ref><ref>{{cite journal |first1=Laurent |last1=Aubouy |first2=Philippe |last2=Gerbier |first3=Nolwenn |last3=Huby |first4=Guillaume |last4=Wantz |first5=Laurence |last5=Vignau |first6=Lionel |last6=Hirsch |first7=Jean-Marc |last7=Jano |title=Synthesis of new dipyridylphenylaminosiloles for highly emissive organic electroluminescent devices |journal=New J. Chem. |volume=28 |issue= |pages=1086–90 |date=2004 |doi=10.1039/b405238b }}</ref> Siloles are efficient in electron transport. They owe their low lying LUMO to a favorable interaction between the antibonding sigma silicon orbital with an antibonding pi orbital of the butadiene fragment.

===Pentacoordinated silicon=== {{See also|Hypervalent molecule#Pentacoordinated silicon}} Unlike carbon, silicon compounds can be coordinated to five atoms as well in a group of compounds ranging from so-called silatranes, such as phenylsilatrane, to a uniquely stable pentaorganosilicate:<ref>{{cite journal |first1=Sirik |last1=Deerenberg |first2=Marius |last2=Schakel |first3=Adrianus H. J. F. |last3=de Keijzer |first4=Mirko |last4=Kranenburg |first5=Martin |last5=Lutz |first6=Anthony L. |last6=Spek |first7=Koop |last7=Lammertsma |title=Tetraalkylammonium pentaorganosilicates: the first highly stable silicates with five hydrocarbon ligands |journal=Chem. Commun. |volume=4 |issue= 4|pages=348–9 |date=2002 |doi=10.1039/b109816k |pmid=12120068 |hdl=1874/14327 |s2cid=20937906 |hdl-access=free }}</ref> :Pentaorganosilicate|frameless

The stability of hypervalent silicon is the basis of the Hiyama coupling, a coupling reaction used in certain specialized organic synthetic applications. The reaction begins with the activation of a Si–C bond by fluoride:

:{{chem2|R\sSiR3' + R"\sX + F- -> R\sR" + R'3SiF + X-}}

==Reactions of Si–C bonds== Unstrained silicon-carbon bonds are stable toward oxygen and water, at least under ambient conditions. Unsaturated silanes are susceptible to electrophilic substitution. Some strong acids will protodesilate arylsilanes and even some alkylsilanes. Most nucleophiles are too weak to displace carbon from silicon: the exceptions are fluoride ions and alkoxides.<ref>{{cite book|pages=240–244|first=Christoph|last=Elschenbroich|title=Organometallics|publisher=Wiley|edition=3rd|translator-first1=José|translator-last1=Oliveira|translator-first2=Christoph|translator-last2=Elschenbroich|orig-date=2005|year=2006|isbn=978-3-527-29390-2}}</ref>

"Simple tetraalkylsilanes are known to undergo random exchange of alkyls in the presence of aluminum halides."<ref>{{Cite journal |last=Frye |first=Cecil L. |last2=Klosowski |first2=Jerome M. |last3=Weyenberg |first3=Donald R. |date=Oct 1970 |title=1,3,5,7-Tetrasilaadamantanes. Facile synthesis via catalyzed ligand redistribution |url=https://pubs.acs.org/doi/abs/10.1021/ja00724a069 |journal=Journal of the American Chemical Society |language=en |volume=92 |issue=21 |pages=6379–6380 |doi=10.1021/ja00724a069 |issn=0002-7863|url-access=subscription }}</ref>

In the Peterson olefination, an organosilicon anion attacks a carbonyl to form an alkene

==Environmental effects== Organosilicon compounds affect bee (and other insect) immune expression, making them more susceptible to viral infection.<ref name="phys.org"/><ref>{{cite journal|last1=Fine|first1=Julia D.|last2=Cox-Foster|first2=Diana L.|last3=Mullin|first3=Christopher A.|date=2017-01-16|title=An Inert Pesticide Adjuvant Synergizes Viral Pathogenicity and Mortality in Honey Bee Larvae|journal=Scientific Reports |volume=7|article-number=40499|doi=10.1038/srep40499|pmc=5238421|pmid=28091574|bibcode=2017NatSR...740499F}}</ref>

==See also== *Compounds of carbon with period 3 elements: **organoaluminum compounds **organophosphorus compounds **organosulfur compounds *Compounds of carbon with other group 14 elements: **organogermanium compounds **organotin compounds **organolead compounds *Silylenes, the carbene counterparts *Silylenoids, the carbenoid counterparts *Decamethylsilicocene

==References== {{Reflist}}

==External links== *Magnus Walter's [http://users.ox.ac.uk/~mwalter/web_05/resources/sil_chem/org_silicon_chem.shtml Selected Aspects of Organosilicon Chemistry] {{Webarchive|url=https://web.archive.org/web/20060504031036/http://users.ox.ac.uk/~mwalter/web_05/resources/sil_chem/org_silicon_chem.shtml |date=2006-05-04 }}<!--dead link--> *[http://www.chem.wisc.edu/areas/reich/OrgMet/silicon.htm Silicon in organic synthesis] *S. Marsden (Editor): [https://www.beilstein-journals.org/bjoc/series/1 Contemporary organosilicon chemistry.] Thematic Series in the Open Access Beilstein Journal of Organic Chemistry.

{{ChemicalBondsToCarbon}} {{Authority control}}

Category:Organosilicon compounds