Hexachlorodisilane
Names
IUPAC name
Hexachlorodisilane
Other names
Perchlorodisilane
Identifiers
3D model (JSmol)
ChemSpider
ECHA InfoCard 100.033.353 Edit this at Wikidata
EC Number
  • 236-704-1
UNII
  • InChI=1S/Cl6Si2/c1-7(2,3)8(4,5)6
    Key: LXEXBJXDGVGRAR-UHFFFAOYSA-N
  • [Si]([Si](Cl)(Cl)Cl)(Cl)(Cl)Cl
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).

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 length of 233 pm.[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 dodecachloroneopentasilane and silicon tetrachloride in presence of Lewis bases even at room temperature.[4]

4 Si2Cl6 → 3 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. ^ a b Simmler, W. "Silicon Compounds, Inorganic", Ullmann's Encyclopedia of Industrial Chemistry, Weinheim: Wiley-VCH. doi:10.1002/14356007.a24_001
  2. ^ T.L. Cottrell, "The Strengths of Chemical Bonds," 2nd ed., Butterworths, London, 1958
  3. ^ 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.
  4. ^ 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
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