Trichlorosilane
| Trichlorosilane | |
|---|---|
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| IUPAC name trichlorosilane | |
| Other names silyl trichloride, silicochloroform | |
| Identifiers | |
| CAS number | 10025-78-2  |
| PubChem | 24811 |
| ChemSpider | 23196 |
| EC number | 233-042-5 |
| UN number | 1295 |
| RTECS number | VV5950000 |
| Jmol-3D images | {{#if:Cl[SiH](Cl)Cl|Image 1 |
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| Properties | |
| Molecular formula | 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 |
| Solubility in water | hydrolysis |
| Hazards | |
| MSDS | ICSC 0591 |
| EU Index | 014-001-00-9 |
| EU classification | Highly flammable (F+) Harmful (Xn) Corrosive (C) |
| R-phrases | R12, R14, R17, R20/22, R29, R35 |
| S-phrases | (S2), S7/9, S16, S26, S36/37/39, S43, S45 |
| NFPA 704 |
 4
3
2
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| Flash point | −27 °C; −17 °F; 246 K |
| Autoignition temperature | 185 °C; 365 °F; 458 K |
| Explosive limits | 1.2–90.5% |
| Related compounds | |
| Related chlorosilanes | Chlorosilane Dichlorosilane Dichloromethylsilane Chlorodimethylsilane Silicon tetrachloride |
| Related compounds | Trifluorosilane Tribromosilane Chloroform |
(verify) (what is: / ?)Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa) | |
| Infobox references | |
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.[1]
Production
Trichlorosilane is produced by treating powdered ferrosilicon with blowing hydrogen chloride at 300 °C. Hydrogen is also produced, as described in the chemical equation:
- Si + 3 HCl → HSiCl3 + 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.
Tank car of trichlorosilane (the blue diamond means "Dangerous when wet").
It is also produced from silicon tetrachloride:[2]
- Si + 3 SiCl4 + 2 H2 → 4 HSiCl3
Applications
Trichlorosilane is the basic ingredient used in the production of purified polysilicons.
- HSiCl3 → Si + HCl + Cl2
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 perfluordecyltrichlorosilane (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 an injection molding tools.[3]
References
- ↑ Lianhong Xu, Ravi Kurukulasuriya, "Trichlorosilane" Encyclopedia of Reagents for Organic Synthesis, 2006. doi:10.1002/047084289X.rt213.pub2
- ↑ Simmler, W. (2005), "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.