Silicon compounds, organic silane

The second largest family of biogas contaminants is volatile organic silicon compounds, namely silanes and siloxanes [1]. 

In comparison to the Si—OR bond, the Si—C bond can be considered essentially unreactive if the organic moiety is a simple unsubstituted hydrocarbon. If the organic moiety is substituted as in the case of a trialkoxysilane, the chemistry is more appropriately considered elsewhere (see Silicon COMPOUNDS, SILANES SILICON COMPOUNDS, SILYLATING AGENTS). 

Chatgilialoglu, C. Ferreri, C. Gimisis, T. Tris(trimethylsilyl)silane in organic synthesis. In Rappoport, Z. Apeloig, Y. (Eds.), The Chemistry of Organic Silicon Compounds, Wiley, Chichester, 1998 Vol. 2, Chapter 25, pp. 1539-1579. 

Silicon, like carbon, is relatively inactive at ordinary temperatures. But, when heated, it reacts vigorously with the halogens (fluorine, chlorine, bromine, cmd iodine) to form halides and with certain metals to form silicides. It is unaffected by all acids except hydrofluoric. At red heat, silicon is attacked by water vapor or by oxygen, forming a surface layer of silicon dioxide. When silicon and carbon are combined at electric furnace temperatures of 2,000 to 2,600 °C (3,600 to 4700 °F), they form silicon carbide (Carborundum = SiC), which is an Importeint abrasive. When reacted with hydrogen, silicon forms a series of hydrides, the silanes. Silicon also forms a series of organic silicon compounds called silicones, when reacted with various organic compounds. 

Gngnard reagents - [BROMINE COMPOUNDS] (Vol 4) - [ESTERS, ORGANIC] (Vol 9) -from benzene [BENZENE] (Vol 4) -chemiluminescence [LUMINESCENTMATERIALS - CHEMILUMINESCENCE] (Vol 15) -magnesium alkyls from [MAGNESIUM COMPOUNDS] (Vol 15) -reaction of propylene oxides [PROPYLENE OXIDE] (Vol 20) -for silanes [SILICON COMPOUNDS - SILANES] (Vol 22) -for sulfoxide synthesis [SULFOXIDES] (Vol 23)... 

Photolysis [KINETTCMEASUREMENTS] (Vol 14) maleic anhydnde [MALEIC ANHYDRIDE, MALEIC ACID AND FUMARIC ACID] (Vol 15) of molybdenum compounds [MOLYBDENUM AND COMPOUNDS] (Vol 16) of pesticides [SOIL CHEMISTRY OF PESTICIDES] (Vol 22) of silanes [SILICON COMPOUNDS - SILANES] (Vol 22) of titanium compounds [TITANIUM COMPOUNDS - ORGANIC] (V ol 24)... 

Compounds of silicon with hydrogen are called silanes. The simplest of these is silane, SiH4. Disilane is H3SiSiH3. Numerous organic silanes exist in which alkyl moieties are substituted for H. 

Comprehensive Organometallic Chemistry Pergamon New York, 1982, Vol. 2. Chapters on Organopolysilanes , Carbocyclic Silanes , Organosilanes , and Silicon Compounds in Organic Synthesis (Vol. 7) by R. West, T. J. Barton, D. A. Armitage, and P. D. Magnus, respectively. 

Silicon compounds with coordination number larger than four are the object of many studies first with respect to their application as catalysts in organic and inorganic syntheses and second as starting materials for the preparation of a broad variety of organosilicon compounds [1]. Additionally, hypervalent silicon hydride compounds can successfully be used as model compounds to study, for instance, the mechanism of nucleophilic substitution reactions, which is of great interest since the silicon atom is able to easily extend its coordination number [1]. Moreover, hypervalent silanes are suitable as starting materials for the synthesis and stabilization of low-valent silanediyl transition metal complexes [2-5]. 

Silanes Organic silicon compounds, in particular used to improve adhesive and ageing properties of surfaces. 

Hypervalent silicon compounds have found wide utility in organic synthesis. In general, pentacoordinated anionic silicates are more reactive toward nucleophiles than are tetracoordinated silanes. For example, Mes2SiF2 is unreactive toward water, while (the 18-crown-6 potassium salt of) Mes2SiF3 is completely hydrolyzed within minutes. Similarly, the pentacoordinate anion HSi(OEt)4 is an effective reducing agent for aldehydes, ketones, and esters at or below room temperature (Scheme 2) no such reaction occurs with HSi(OEt)3. The difference in relative reactivities of hypervalent and nonhypervalent species is relevant to the intermediates proposed in Section 7.6. 

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