organosilici

Organosilicon compounds, also called organosilici in Italian, are chemical species that contain at least one carbon–silicon (C–Si) bond. They encompass a broad range of structures, from simple organosilanes and hydrosilanes to complex polymers such as polysiloxanes (silicones). The alkyl, aryl, vinyl, and other substituents attached to silicon influence properties such as reactivity, stability, and hydrolytic resistance, yielding materials with low surface energy and high thermal stability.

Major classes include organosilanes (R3Si–R′), where Si–C bonds attach carbon skeletons to silicon; organosiloxanes (silicones) with Si–O–Si backbones and organic groups on silicon; and silicon-centered reagents such as vinylsilanes and hydrosilanes (Si–H). Organosilicon compounds are used to introduce silicon-containing motifs in synthesis and materials science, and many are characterized by relatively low reactivity toward water compared with other heteroatom chemistries.

Synthetic methods form Si–C bonds and utilize Si–H functionality. Hydrosilylation adds Si–H across C=C or C≡C bonds under metal catalysis. The Hiyama cross‑coupling uses organosilicon reagents activated by fluoride to couple with aryl or vinyl halides under palladium or nickel catalysts. Other routes include Grignard‑ or organolithium-mediated silylation and formation of Si–C bonds via silyl transfer reactions.

Applications span silicone polymers for coatings, adhesives, sealants, lubricants, and cosmetics; organosilane coupling agents used to improve adhesion; protecting groups such as tert-butyldimethylsilyl (TBDMS) for alcohols in organic synthesis; and precursors for electronics, optoelectronics, and silicone-based elastomers. Safety and environmental considerations depend on the specific compound, with some hydrosilanes being reactive or flammable and hydrolysis yielding silanols and silica.