Hexachlorodisilane is the
inorganic compound
An inorganic compound is typically a chemical compound that lacks carbon–hydrogen bondsthat is, a compound that is not an organic compound. The study of inorganic compounds is a subfield of chemistry known as ''inorganic chemistry''.
Inorgan ...
with the
chemical formula
A chemical formula is a way of presenting information about the chemical proportions of atoms that constitute a particular chemical compound or molecule, using chemical element symbols, numbers, and sometimes also other symbols, such as pare ...
Si
2Cl
6.
[Simmler, W. "Silicon Compounds, Inorganic", ''Ullmann's Encyclopedia of Industrial Chemistry'', Weinheim: Wiley-VCH. ] 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
Ethane ( , ) is a naturally occurring Organic compound, organic chemical compound with chemical formula . At standard temperature and pressure, ethane is a colorless, odorless gas. Like many hydrocarbons, ethane is List of purification methods ...
, with a single Si-Si bond length of 233 pm.
Hexachlorodisilane is produced in the chlorination of silicides such as e.g. calcium silicide. Idealized syntheses are as follows:
:CaSi
2 + 4 Cl
2 → Si
2Cl
6 + CaCl
2
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
Silicon tetrachloride or tetrachlorosilane is the inorganic compound with the formula SiCl4. It is a colorless volatile liquid that fumes in air. It is used to produce high purity silicon and silica for commercial applications. It is a part of the ...
in presence of Lewis bases even at room temperature.
[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]
:4 Si
2Cl
6 → 3 SiCl
4 + Si
5Cl
12
This conversion is useful in making silicon-based components of use in semiconducting devices including photovoltaic cells.
The compound is also useful
reagent
In chemistry, a reagent ( ) or analytical reagent is a substance or compound added to a system to cause a chemical reaction, or test if one occurs. The terms ''reactant'' and ''reagent'' are often used interchangeably, but reactant specifies a ...
for the
deoxygenation reactions, such as this general process involving a phosphine oxide:
:2 Si
2Cl
6 + OPR
3 → OSi
2Cl
6 + PR
3
References
Chlorosilanes