Dimethylsilanediol or DMSD is an organosilicon compound with the chemical formula . It is a colorless crystalline solid. It belongs to the category of silanols. Molecule of dimethylsilanediol has tetrahedral molecular geometry, where two methyl and two hydroxyl groups are attached to the central silicon atom. Dimethylsilanediol is a silicon analog of unstable propane-2,2-diol , where the central C atom is replaced by Si atom.
Synthesis Dimethylsilanediol is produced by hydrolysis of dichlorodimethylsilane.
Dimethylsilanediol, while not sold commercially, has been demonstrated to be one of the degradation product of polydimethylsiloxane polymers and oligomers in the environment.
Uses It is a reaction intermediate in the synthesis of organosilicon compounds such as polydimethylsiloxane.
Reactions and properties Dimethylsilanediol readily polymerizes to give a mixture of polydimethylsiloxanes, primarily composed of the cyclomethicones octamethylcyclotetrasiloxane (D4), decamethylcyclopentasiloxane (D5), and dodecamethylcyclohexasiloxane (D6), but also containing a small amount of dimethiconol, the linear polymer. It is hygroscopic and temperature sensitive. It should be kept under inert atmosphere. Because it having two hydroxyl groups, it has ability to form hydrogen bonds, which enhances its solubility in polar solvents.
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