Trisilane
Chemical compound
From Wikipedia, the free encyclopedia
Trisilane is the silane with the formula H2Si(SiH3)2. A liquid at standard temperature and pressure, it is a silicon analogue of propane. In contrast with propane, however, trisilane ignites spontaneously in air.[2]
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| Names | |||
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| IUPAC name
Trisilane | |||
| Identifiers | |||
3D model (JSmol) |
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| ChemSpider | |||
| ECHA InfoCard | 100.132.113 | ||
| EC Number |
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PubChem CID |
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| UNII | |||
| UN number | 3194 | ||
CompTox Dashboard (EPA) |
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| Properties | |||
| H8Si3 | |||
| Molar mass | 92.319 g·mol−1 | ||
| Appearance | Colourless liquid | ||
| Odor | Unpleasant | ||
| Density | 0.743 g cm−3 | ||
| Melting point | −117 °C (−179 °F; 156 K) | ||
| Boiling point | 53 °C (127 °F; 326 K) | ||
| Slowly decomposes[1] | |||
| Vapor pressure | 12.7 kPa | ||
| Hazards | |||
| Occupational safety and health (OHS/OSH): | |||
Main hazards |
Pyrophoric | ||
| GHS labelling: | |||
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| Danger | |||
| H250, H261, H315, H319, H335 | |||
| P210, P222, P231+P232, P261, P264, P271, P280, P302+P334, P302+P352, P304+P340, P305+P351+P338, P312, P321, P332+P313, P337+P313, P362, P370+P378, P402+P404, P403+P233, P405, P422, P501 | |||
| Flash point | < −40 °C (−40 °F; 233 K) | ||
| < 50 °C (122 °F; 323 K) | |||
| Related compounds | |||
Related hydrosilicons |
Disilane Disilyne Silane Silylene | ||
Related compounds |
Propane | ||
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Synthesis
Trisilane was characterized by Alfred Stock having prepared it by the reaction of hydrochloric acid and magnesium silicide.[3][4] This reaction had been explored as early as 1857 by Friedrich Woehler and Heinrich Buff, and further investigated by Henri Moissan and Samuel Smiles in 1902.[2]
Decomposition
The key property of trisilane is its thermal lability. It degrades to silicon films and SiH4 according to this idealized equation:
- Si3H8 → Si + 2 SiH4
In terms of mechanism, this decomposition proceeds by a 1,2 hydrogen shift that produces disilanes, normal and isotetrasilanes, and normal and isopentasilanes.[5]
Because it readily decomposes to leave films of Si, trisilane has been explored a means to apply thin layers of silicon for semiconductors and similar applications.[6] Similarly, thermolysis of trisilane gives silicon nanowires.[7]