Disiloxane

Not to be confused with Hexamethyldisiloxane.

Disiloxane
IUPAC name Disiloxane
Other names Disilyl ether Disilyl oxide Hexahydrodisiloxane Perhydrodisiloxane Silyl ether Silyl oxide
Identifiers
Abbreviations	DS DSE DSO
CAS number	13597-73-4 Y
PubChem	123318
ChemSpider	109921 Y
MeSH	Disiloxane
ChEBI	CHEBI:48141
Gmelin Reference	1206
Jmol-3D images	Image 1
SMILES [SiH3]O[SiH3]
InChI InChI=1S/H6OSi2/c2-1-3/h2-3H3 Y Key: KPUWHANPEXNPJT-UHFFFAOYSA-N Y
Properties
Molecular formula	H6OSi2
Molar mass	78.22 g mol−1
Exact mass	77.995717880 g mol-1
Appearance	Colorless gas
Melting point	-144 °C, 129 K, -227 °F
Boiling point	-15.2 °C, 258 K, 5 °F
Dipole moment	0.24 D
Structure
Crystal structure	Orthorhombic
Space group	Pmm2
Molecular shape	Bent
Hazards
MSDS	External MSDS
NFPA 704	4 2 1
Related compounds
Related compounds	Dimethyl ether Disilane Silane Silanol Trisilane
Supplementary data page
Structure and properties	n, εr, etc.
Thermodynamic data	Phase behaviour Solid, liquid, gas
Spectral data	UV, IR, NMR, MS
Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

Disiloxane (DSO) is a hydrogen-bearing silicon compound with the formula H₃SiOSiH₃ analog to methyl ether in organic chemistry. It is the simplest silicon ether and a colourless gas.

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.