Chemistry:Hexamethyldisilane
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| Names | |||
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| Preferred IUPAC name
Hexamethyldisilane | |||
| Identifiers | |||
3D model (JSmol)
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| 1633463 | |||
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| EC Number |
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PubChem CID
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| UNII | |||
| UN number | 1993 | ||
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| Properties | |||
| 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)
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1.422 | ||
| Thermochemistry | |||
Std molar
entropy (S |
255.89 J K−1 mol−1 (at 22.52 °C) | ||
| Hazards | |||
| GHS pictograms |   
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| GHS Signal word | DANGER | ||
| H225, H319, H334, H335 | |||
| P210, P261, P305+351+338, P342+311 | |||
| Flash point | 11 °C (52 °F; 284 K) | ||
| Related compounds | |||
Related alkylsilanes
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Tetramethylsilane | ||
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). | |||
 verify (what is   ?)
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| Infobox references | |||
Tracking categories (test):
Hexamethyldisilane (TMS2) is the organosilicon compound with the formula Si2(CH3)6, abbreviated Si2Me6. It is a colourless liquid, soluble in organic solvents.[1]
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:[2]
- 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.[3]
- Me3Si−SiMe3 + I2 → 2 SiMe3I
References
- ↑ Tamejiro Hiyama, Manabu Kuroboshi, "Hexamethyldisilane" Encyclopedia of Reagents for Organic Synthesis, 2001 John Wiley & Sons. doi:10.1002/047084289X.rh015
- ↑ Fürstner, Alois; Weidmann, Hans (1988). "Efficient formation and cleavage of disilanes by potassium-graphite. Silylation with silyl metal reagents". Journal of Organometallic Chemistry 354: 15–21. doi:10.1016/0022-328X(88)80634-X.
- ↑ Olah, G.; Narang, S.C. (1982). "Iodotrimethylsilane—a versatile synthetic reagent". Tetrahedron 38 (15): 2225. doi:10.1016/0040-4020(82)87002-6.
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