Hydrosilane

Hydrosilane refers to organosilicon compounds that contain at least one silicon–hydrogen (Si–H) bond. The class includes simple hydrides such as silane (SiH4) and organosilanes of the form RnSiHm, as well as more complex silanes used as reagents and monomers in silicone chemistry.

Structure and examples: The Si–H bond is polar, and the reactivity of hydrosilanes is influenced by the substituents attached to silicon. Common members include SiH4, methylsilane (CH3SiH3), dimethylsilane (CH3)2SiH2, and triphenylsilane (Ph3SiH).

Preparation: Hydrosilanes are prepared by reduction of chlorosilanes or other Si–Cl precursors, by hydrosilylation reactions that install Si–H bonds on carbon frameworks, and by industrial routes that reduce silicon compounds with hydrogen under catalytic conditions.

Reactions and uses: Hydrosilanes are widely used as hydride donors in catalytic hydrosilylation, where Si–H adds across alkenes and alkynes to form Si–C bonds. They can be oxidized to silanols, and serve as reducing reagents in transfer hydrosilylation of carbonyls and imines. They are also key precursors in silicone manufacture and related polymer chemistry.

Safety and handling: Hydrosilanes range from gases to liquids; many are flammable and some are toxic or irritant. Silanes such as SiH4 are pyrophoric and require stringent handling, inert atmosphere, and proper ventilation, with appropriate protective equipment.