CH32SiCl2

CH32SiCl2, commonly written as (CH3)2SiCl2, is an organosilicon dichloride known as dichlorodimethylsilane. The molecule features a silicon atom tetrahedrally coordinated to two methyl groups and two chlorine ligands. It is a moisture-sensitive, reactive intermediate used in silicone and organosilicon chemistry.

Preparation and handling

CH32SiCl2 is typically prepared by chlorination of the hydrosilane (CH3)2SiH2 with chlorine: (CH3)2SiH2 + 2 Cl2 → (CH3)2SiCl2 + 2 HCl. The compound is a volatile liquid that rapidly hydrolyzes in the presence of water or moisture, forming the corresponding silanol (CH3)2Si(OH)2, which can further condense to siloxane networks. It readily reacts with alcohols to give dialkoxydimethylsilane derivatives and HCl.

Reactions and properties

As a chlorosilane, CH32SiCl2 undergoes typical chlorosilane chemistry, including hydrolysis, alkoxylation, and condensation reactions. It can be used to install dimethylsilyl groups onto substrates or as a precursor to silicone polymers and resins through subsequent hydrolysis and polycondensation steps.

Applications

CH32SiCl2 serves as a versatile building block in organosilicon synthesis. It is used to prepare methylated siloxanes, crosslinking agents for silicone resins, and surface-modifying agents. Through hydrolysis or alkoxylation, it enables formation of siloxane networks and various silicone materials.

Safety

This compound is corrosive and reacts with moisture to release HCl and heat. It must be handled under strictly anhydrous conditions, stored sealed under inert atmosphere, and used with appropriate personal protective equipment and adequate ventilation. Contact with skin or eyes should be avoided.