Trichlorosilane is an inorganic compound with the formula HSiCl3. 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.
silyl trichloride, silicochloroform
3D model (JSmol)
CompTox Dashboard (EPA)
|Molar mass||135.45 g/mol|
|Melting point||−126.6 °C (−195.9 °F; 146.6 K)|
|Boiling point||31.8 °C (89.2 °F; 304.9 K)|
|Safety data sheet||ICSC 0591|
|Highly flammable (F+)|
|R-phrases (outdated)||R12, R14, R17, R20/22, R29, R35|
|S-phrases (outdated)||(S2), S7/9, S16, S26, S36/37/39, S43, S45|
|Flash point||−27 °C (−17 °F; 246 K)|
|185 °C (365 °F; 458 K)|
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
|what is ?)(|
- Si + 3 HCl → HCl3Si + H2
Yields of 80-90% can be achieved. The major byproducts are silicon tetrachloride (chemical formula SiCl4), hexachlorodisilane (Si2Cl6), and dichlorosilane (H2SiCl2), from which trichlorosilane can be separated by distillation.
- Si + 3 SiCl4 + 2 H2 → 4 HSiCl3
Trichlorosilane is the basic ingredient used in the production of purified polysilicon.
- HSiCl3 → Si + HCl + Cl2
Ingredient in hydrosilylationEdit
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.
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.
- 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. 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