Silane is an inorganic compound with chemical formula, Si H₄, making it a group 14 hydride. It is a colourless, flammable gas with a sharp, repulsive smell, somewhat similar to that of acetic acid. Silane is of practical interest as a precursor to elemental silicon.

Silanes refer to many compounds with four substituents on silicon, including an organosilicon compound. Examples include trichlorosilane (SiHCl₃), tetramethylsilane (Si(CH₃)₄), and tetraethoxysilane (Si(OC₂H₅)₄).

Silane can be produced by several routes. Typically, it arises from the reaction of hydrogen chloride with magnesium silicide:

It is also prepared from metallurgical grade silicon in a two-step process. First, silicon is treated with hydrogen chloride at about 300 °C to produce trichlorosilane, HSiCl₃, along with hydrogen gas, according to the chemical equation:

The trichlorosilane is then converted to a mixture silane and silicon tetrachloride. This redistribution reaction requires a catalyst:

The most commonly used catalysts for this process are metal halides, particularly aluminium chloride. This is referred to as a redistribution reaction, which is a double displacement involving the same central element. It may also be thought of as a disproportionation reaction even though there is no change in the oxidation number for silicon (Si has a nominal oxidation number IV in all three species). However, the utility of the oxidation number concept for a covalent molecule, even a polar covalent molecule, is ambiguous. The silicon atom could be rationalized as having the highest formal oxidation state and partial positive charge in SiCl₄ and the lowest formal oxidation state in SiH₄ since Cl is far more electronegative than is H.

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