SiHCl3

SiHCl3, commonly called trichlorosilane, is a silicon hydride chloride with the formula SiHCl3. The silicon atom is tetrahedrally coordinated, bearing one hydrogen and three chlorine substituents. In its pure form, it is a colorless, volatile liquid that fumes in air and is moisture sensitive.

Physical properties of SiHCl3 reflect its volatility and reactivity. It is readily hydrolyzed by water or moisture to form silica or hydrated silica and hydrogen chloride, an exothermic and corrosive reaction. It is typically handled under dry, inert atmospheres and stored in corrosion-resistant containers.

Industrial preparation of SiHCl3 commonly proceeds by hydrogenolysis of silicon tetrachloride: SiCl4 + H2 → SiHCl3 + HCl, often in the presence of catalysts. Other routes involve partial reduction of chlorosilanes or controlled chlorination/hydride transfer steps from related silicon compounds. The compound is volatile and can be distilled under appropriate inert conditions.

Applications of SiHCl3 center on its role as a silicon precursor in materials processing. It is used as a feedstock for chemical vapor deposition and other processing routes to produce high-purity silicon and silicon-containing materials. In the semiconductor and photovoltaic industries, trichlorosilane-related chemistries contribute to the preparation of silicon layers and powders, typically after appropriate purification and reduction steps.

Hazards and handling considerations: SiHCl3 is corrosive and reacts violently with water, generating hydrochloric acid and silica species. Contact with skin or eyes must be avoided, and inhalation or ingestion should be prevented. Storage and use require appropriate fume control, dry handling, and protective equipment.