Trichlorosilane
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Names | |||
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IUPAC name
trichlorosilane
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Other names
silyl trichloride, silicochloroform
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Identifiers | |||
3D model (JSmol)
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ChemSpider | |||
ECHA InfoCard | 100.030.026 ![]() | ||
EC Number |
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PubChem CID
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RTECS number |
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UNII | |||
UN number | 1295 | ||
CompTox Dashboard (EPA)
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Properties | |||
HCl3Si | |||
Molar mass | 135.45 g/mol | ||
Appearance | colourless liquid | ||
Density | 1.342 g/cm3 | ||
Melting point | −126.6 °C (−195.9 °F; 146.6 K) | ||
Boiling point | 31.8 °C (89.2 °F; 304.9 K) | ||
hydrolysis | |||
Hazards[1] | |||
Safety data sheet (SDS) | ICSC 0591 | ||
GHS labelling: | |||
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Signal word
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Danger | ||
H224, H250, H302, H314, H332 | |||
P231, P280, P305+P351+P338+P310, P310, P370+P378 | |||
NFPA 704 (fire diamond) | ![]()
3
4
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Flash point | −27 °C (−17 °F; 246 K) | ||
185 °C (365 °F; 458 K) | |||
Explosive limits | 1.2–90.5% | ||
Related compounds | |||
Related chlorosilanes
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Chlorosilane Dichlorosilane Chlorodimethylsilane Silicon tetrachloride | ||
Related compounds
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Trifluorosilane Tribromosilane Chloroform | ||
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). | |||
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Infobox references | |||
Trichlorosilane is an inorganic compound with the formula HCl3Si. It is a colourless, volatile liquid. Purified trichlorosilane is the principal precursor to ultrapure silicon in the semiconductor industry. In water, it rapidly decomposes to produce a silicone polymer while giving off hydrochloric acid. Because of its reactivity and wide availability, it is frequently used in the synthesis of silicon-containing organic compounds.[2]
Production[]
Trichlorosilane is produced by treating powdered metallurgical grade silicon with blowing hydrogen chloride at 300 °C. Hydrogen is also produced, as described in the chemical equation:
- Si + 3 HCl → HCl3Si + H2
Yields of 80-90% can be achieved. The main byproducts are silicon tetrachloride (chemical formula SiCl4), hexachlorodisilane (Si2Cl6) and dichlorosilane (H2SiCl2), from which trichlorosilane can be separated by distillation.
- Tank car of trichlorosilane (the blue diamond means "Dangerous when wet")
It is also produced from silicon tetrachloride:[3]
- Si + 3 SiCl4 + 2 H2 → 4 HCl3Si
Applications[]
Trichlorosilane is the basic ingredient used in the production of purified polysilicon.
- HCl3Si → Si + HCl + Cl2
Ingredient in hydrosilylation[]
Via hydrosilylation, trichlorosilane is a precursor to other useful organosilicon compounds:
- RCH=CH2 + HSiCl3 → RCH2CH2SiCl3
Some useful products of this or similar reactions include octadecyltrichlorosilane (OTS), perfluoroctyltrichlorosilane (PFOTCS), and perfluorodecyltrichlorosilane (FDTS). These reagents used in surface science and nanotechnology to form Self-assembled monolayers. Such layers containing fluorine decrease surface energy and reduce sticking. This effect is usually exploited as coating for MEMS and microfabricated stamps for a nanoimprint lithography (NIL) and in injection molding tools.[4]
Organic synthesis[]
Trichlorosilane is a reagent in the conversion of benzoic acids to toluene derivatives. In the first step of a two-pot reaction, the carboxylic acid is first converted to the trichlosilylbenzyl compound. In the second step, the benzylic silyl derivative is converted to the toluene derivative with base.[5]
References[]
- ^ "GESTIS-Stoffdatenbank". gestis.dguv.de.
- ^ Lianhong Xu, Ravi Kurukulasuriya, "Trichlorosilane" Encyclopedia of Reagents for Organic Synthesis, 2006. doi:10.1002/047084289X.rt213.pub2
- ^ Simmler, W. "Silicon Compounds, Inorganic". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a24_001.
- ^ Cech J, Taboryski R (2012). "Stability of FDTS monolayer coating on aluminum injection molding tools". Applied Surface Science. 259: 538–541. Bibcode:2012ApSS..259..538C. doi:10.1016/j.apsusc.2012.07.078.
- ^ George S. Li, David F. Ehler, R. A. Benkeser "Methyl Groups By Reduction Of Aromatic Carboxylic Acids With Trichlorosilane - Tri-n-propylamine: 2-methylbiphenyl" Org. Synth. 1977, volume 56, pp. 83. doi:10.15227/orgsyn.056.0083
- Silanes
- Chlorides