Formula Si2Cl6 Appearance Colorless liquid | Molar mass 268.88 g/mol | |
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Hexachlorodisilane is the inorganic compound with the chemical formula Si2Cl6, 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.
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Structure and synthesis
The molecule adopts a structure like ethane, with a single Si-Si bond of length 0.233 nm.
Hexachlorodisilane is produced in the chlorination of silicides such as e.g. calcium silicide. Idealized syntheses are as follows:
CaSi2 + 4 Cl2 → Si2Cl6 + CaCl2Reactions 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 Si2Cl6 → 3 SiCl4 + Si5Cl12This conversion is useful in making silicon-based components of use in semiconducting devices including photovoltaic cells.
The compound is also useful reagent for the deoxygenation reactions, such as this general process involving a phosphine oxide:
2 Si2Cl6 + OPR3 → OSi2Cl6 + PR3