Hexachlorodisiloxane

Hexachlorodisiloxane is a chemical compound composed of chlorine, silicon, and oxygen. Structurally, it is the symmetrical ether of two trichlorosilyl groups, and can be synthesized via high-temperature oxidation of silicon tetrachloride: $${\ce {2SiCl4{}+O2->[ \atop {950-970\,^{\circ }{\text{C}}}]2(SiCl3)2O{}+Cl2}}$$

Hexachlorodisiloxane

Identifiers
CAS Number	14986-21-1 Y
3D model (JSmol)	Interactive image
ChemSpider	76449
ECHA InfoCard	100.035.504
EC Number	239-070-4
PubChem CID	84745
CompTox Dashboard (EPA)	DTXSID2065836
InChI InChI=1S/Cl6OSi2/c1-8(2,3)7-9(4,5)6 Key: QHAHOIWVGZZELU-UHFFFAOYSA-N
SMILES O([Si](Cl)(Cl)Cl)[Si](Cl)(Cl)Cl
Properties
Chemical formula	Cl6OSi2
Molar mass	284.87 g·mol−1
Density	1.575 g/cm3
Melting point	−33 °C (−27 °F; 240 K)
Boiling point	137 °C (279 °F; 410 K)
Hazards
GHS labelling:
Pictograms
Signal word	Danger
Hazard statements	H223, H314, H335
Related compounds
Other anions	Hexafluorodisiloxane
Other cations	Perchloromethylether
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

At room temperature, it is a colorless liquid that hydrolyzes upon exposure to water to give silicon dioxide and hydrochloric acid: $${\ce {(SiCl3)2O + 3H2O -> 2SiO2 + 6HCl}}$$ Intense heat evinces a similar decomposition: $${\ce {2(SiCl3)2O->[ \atop {\Delta }]SiO2{}+3SiCl4}}$$

Reaction with antimony trifluoride gives the analogous hexafluorodisiloxane.

Sources

• Lide, David R., ed. (2009). CRC Handbook of Chemistry and Physics (90th ed.). Boca Raton, Florida: CRC Press. ISBN 978-1-4200-9084-0.
• G. Brauer [Брауэр Г.], ed. (1985). Руководство по неорганическому синтезу [Guide to Inorganic Synthesis] (in Russian). Vol. 3. Moscow: Mir. p. 392.
• K. A. Adrianov [Адрианов К. А.] (1955). Кремнийорганические соединения [Organosilicon Compounds] (in Russian). Moscow: State scientific and technical publishing house of chemical literature. p. 521.
• Booth, Harold Simmons; Osten, Reuben Alexander (July 1945). "The Fluorination of Chlorodisiloxane / Silicon Oxyfluoride". Journal of the American Chemical Society. 67 (7): 1092–1096. doi:10.1021/ja01223a021.