Hexachlorodisilane
 | |
| Names | |
|---|---|
| IUPAC name
Hexachlorodisilane | |
| Other names
Disilicon hexachloride | |
| Identifiers | |
| 13465-77-5 | |
| Properties | |
| Si2Cl6 | |
| Molar mass | 268.88 g/mol |
| Appearance | Colorless liquid |
| Melting point | −1 °C (30 °F; 272 K) |
| Boiling point | 144 °C (291 °F; 417 K) |
| Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). | |
| Infobox references | |
Hexachlorodisilane is the inorganic compound with the chemical formula Si2Cl6,[1] It is a colourless liquid that fumes in moist air. It has specialty applications in as a reagent and as a volatile precursor to silicon metal.
Structure and synthesis
The molecule adopts a structure like ethane, with a single Si-Si bond of length 0.233 nm.[2]
Hexachlorodisilane is produced in the chlorination of silicides such as e.g. calcium silicide. Idealized syntheses are as follows:[3]
- CaSi2 + 4 Cl2 → Si2Cl6 + CaCl2
Reactions and uses
Hexachlorodisilane is stable under air or nitrogen at temperatures of at least up to 400°C for several hours, but decomposes to dodekachloroneopentasilane and silicon tetrachloride in presence of Lewis bases even at room temperature. [4]
- 3 Si2Cl6 → SiCl4 + Si5Cl12
This conversion is useful in making silicon-based components of use in semiconducting devices including photovoltaic cells.[1]
The compound is also useful reagent for the deoxygenation reactions, such as this general process involving a phosphine oxide:
- 2 Si2Cl6 + OPR3 → OSi2Cl6 + PR3
References
- 1 2 Simmler, W. "Silicon Compounds, Inorganic", Ullmann's Encyclopedia of Industrial Chemistry, Weinheim: Wiley-VCH. doi:10.1002/14356007.a24_001
- ↑ T.L. Cottrell, "The Strengths of Chemical Bonds," 2nd ed., Butterworths, London, 1958.
- ↑ Seo, E.S.M; Andreoli, M; Chiba, R (2003). "Silicon tetrachloride production by chlorination method using rice husk as raw material". Journal of Materials Processing Technology 141 (3): 351. doi:10.1016/S0924-0136(03)00287-5.
- ↑ Emeleus, H. J., and Muhammad Tufail. "Reaction of Hexachlorodisilane with Bases and Alkyl Halides." Journal of Inorganic and Nuclear Chemistry 29.8 (1967): 2081-084.