Chemistry:Hexamethyldisilane

Hexamethyldisilane

Names
Preferred IUPAC name Hexamethyldisilane
Identifiers
CAS Number	1450-14-2 Y
3D model (JSmol)	Interactive image
Beilstein Reference	1633463
ChemSpider	66675 Y
EC Number	215-911-0
PubChem CID	74057
RTECS number	JM9170000
UNII	A7HH2E9DUB Y
UN number	1993
InChI InChI=1S/C6H18Si2/c1-7(2,3)8(4,5)6/h1-6H3 Y Key: NEXSMEBSBIABKL-UHFFFAOYSA-N Y
SMILES C[Si](C)(C)[Si](C)(C)C
Properties
Chemical formula	Si2C6H18
Molar mass	146.39 g mol−1
Appearance	Colourless liquid
Density	0.715 g/cm3
Melting point	14 °C; 57 °F; 287 K
Boiling point	113 °C; 235 °F; 386 K
Refractive index (nD)	1.422
Thermochemistry
Std molar entropy (So298)	255.89 J K−1 mol−1 (at 22.52 °C)
Hazards
GHS pictograms
GHS Signal word	DANGER
GHS hazard statements	H225, H319, H334, H335
GHS precautionary statements	P210, P261, P305+351+338, P342+311
Flash point	11 °C (52 °F; 284 K)
Related compounds
Related alkylsilanes	Tetramethylsilane Triethylsilane
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Infobox references

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Hexamethyldisilane (TMS₂) is the organosilicon compound with the formula Si₂(CH₃)₆, abbreviated Si₂Me₆. It is a colourless liquid, soluble in organic solvents.

Synthesis and reactions

Hexamethyldisilane can be produced by Wurtz-like coupling of trimethylsilyl chloride in the presence of a reducing agent such as potassium graphite:

2 Me
3SiCl + 2 K → Me
3Si–SiMe
3 + 2 KCl

With an excess of the reductant, the alkali metal silyl derivative is produced:

Me
3Si–SiMe
3 + 2 K → 2 Me
3SiK

The Si-Si bond in hexamethyldisilane is cleaved by strong nucleophiles and electrophiles. Alkyl lithium compounds react as follows:

Si₂Me₆ + RLi → RSiMe₃ + LiSiMe₃

Iodine gives trimethylsilyl iodide.

Me₃Si−SiMe₃ + I₂ → 2 SiMe₃I