Silanyl

Silanyl is a term used in organosilicon chemistry to denote a silicon-centered substituent based on the silane framework, typically the silanyl group SiH3 attached to a parent molecule. In this context, silanyl refers to the SiH3– unit and its connectivity to the rest of the molecule. The term is related to the broader family of silyl groups, but silanyl emphasizes a hydrosilane-derived fragment and is sometimes distinguished from more common silyl protecting groups such as trimethylsilyl (TMS).

Chemical structure and reactivity: A silanyl fragment consists of a silicon atom bonded to three hydrogen atoms and to the remainder of the molecule. The Si–H bonds confer reactivity that can be exploited in various transformations, including hydrosilylation of unsaturated substrates and other silicon-centered functionalizations. Because silicon-hydrogen bonds are relatively reactive under certain conditions, silanyl groups can be installed, manipulated, or transformed in situ to give other silicon-containing functionalities.

Synthesis and applications: Silanyl groups can be introduced through reactions that generate Si–H bearing silicon centers, such as hydrosilylation or reduction of silicon-containing precursors. In practice, silanyl chemistry is used as an intermediate step in the preparation of more stable silicon-containing compounds, or as a transient moiety that can be converted into silyl ethers, siloxanes, or other organosilicon frameworks. The terminology is more common in older or more specialized literature, with modern discussions often favoring broader terms like silanyl, silane, or silyl depending on the context.

Safety: Silane-related species, including silanyl fragments, are typically moisture- and air-sensitive and may be flammable or reactive. Proper handling in well-ventilated, inert environments is advised, with attention to hydrogen evolution and potential hazards associated with silicon hydrides.

See also: Silane, Silyl group, Hydrosilylation, Organosilicon chemistry.