Disiloxane

Not to be confused with Hexamethyldisiloxane.
Disiloxane
Structural formula of disiloxane with explicit hydrogens
Ball-and-stick model of the disiloxane molecule
Names
IUPAC name
Disiloxane
Other names
Disilyl ether

Disilyl oxide
Hexahydrodisiloxane
Perhydrodisiloxane
Silyl ether

Silyl oxide
Identifiers
13597-73-4 YesY
3D model (Jmol) Interactive image
Abbreviations DS

DSE
DSO

ChEBI CHEBI:48141
ChemSpider 109921 YesY
1206
MeSH Disiloxane
PubChem 123318
Properties
H6OSi2
Molar mass 78.22 g·mol−1
Appearance Colorless gas
Melting point −144 °C (−227 °F; 129 K)
Boiling point −15.2 °C (4.6 °F; 257.9 K)
0.24 D
Structure
Orthorhombic
Pmm2
Bent
Hazards
Safety data sheet See: data page
NFPA 704
Flammability code 4: Will rapidly or completely vaporize at normal atmospheric pressure and temperature, or is readily dispersed in air and will burn readily. Flash point below 23 °C (73 °F). E.g., propane Health code 2: Intense or continued but not chronic exposure could cause temporary incapacitation or possible residual injury. E.g., chloroform Reactivity code 1: Normally stable, but can become unstable at elevated temperatures and pressures. E.g., calcium Special hazards (white): no codeNFPA 704 four-colored diamond
4
2
1
Related compounds
Related compounds
 Dimethyl ether

Disilane
Silane
Silanol
Trisilane

Supplementary data page
Refractive index (n),
Dielectric constant (εr), etc.
Thermodynamic
data
 Phase behaviour
solid–liquid–gas
UV, IR, NMR, MS
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references

Disiloxane /ˈdaɪˈsaɪlɒkseɪn/ is a chemical compound with the chemical formula Si
2H
6O. It is the simplest siloxane, or oxasilane.

Properties and bonding

Disiloxane is a molecule with six equivalent Si-H bonds and two equivalent Si-O bonds.

At room temperature and standard pressure, disiloxane is a colourless, pungent gas. Disiloxane has a boiling point of −15 °C (5 °F) at a pressure of one atmosphere.

Production

Today, DSO is primarily produced by converting silane or silicon via gasification to a mixture of silicon monoxide, and hydrogen. This mixture is then converted into DSO in the presence of a catalyst. As described, this is a one-step (direct synthesis) process that permits both silanol synthesis and dehydration in the same process unit, with no silanol isolation and purification. Disiloxane reacts at low temperatures with aluminium halides to give the corresponding silyl and silylene halides and monosilane. Disiloxane is generally considered to be stable in water. It is more soluble than dimethyl ether. It hydrolyses very slowly:

H3SiOSiH3 + 3 H2O → 2 SiO2 + 6 H2

Alternatively disiloxane can be prepared in the lab according to the following reactions:

H3SiX + H2O → H3SiOH + HX
2 H3SiOH → H3SiOSiH3 + H2O

Unlike dimethyl ether, it can be produced via autocondensation without a catalyst, as silanol is relatively unstable.

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