Chemistry:Trisilane

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Trisilane
Stereo structural formula of trisilane with implicit hydrogens
Ball and stick model of trisilane
Names
IUPAC name
Trisilane
Identifiers
3D model (JSmol)
ChemSpider
EC Number
  • 616-514-9
UNII
UN number 3194
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
Main hazards Pyrophoric
GHS pictograms GHS02: FlammableGHS07: Harmful
GHS Signal word Danger
H250, H261, H315, H319, H335
P210, P222, P231+232, P261, P264, P271, P280, P302+334, P302+352, P304+340, P305+351+338, P312, P321, P332+313, P337+313, P362, P370+378, P402+404, P403+233, 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).
Infobox references

Trisilane is the silane with the formula H2Si(SiH3)2. A liquid at standard temperature and pressure, it is a silicon analogue of propane. The contrast with propane however trisilane ignites spontaneously in air.[2]

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]


References

  1. Alfred Walter Stewart (1926) (in English). Recent Advances in Physical and Inorganic Chemistry. Longmans, Green and Company, Limited. pp. 312. https://www.google.com/books/edition/Recent_Advances_in_Physical_and_Inorgani/o3MVAQAAIAAJ?hl=en&gbpv=0. Retrieved 11 May 2021. 
  2. 2.0 2.1 P. W. Schenk (1963). "Silanes". in G. Brauer. Handbook of Preparative Inorganic Chemistry, 2nd Ed.. 1. NY, NY: Academic Press. pp. 680. 
  3. Stock, Alfred; Somieski, Carl (1916). "Siliciumwasserstoffe. I. Die aus Magnesiumsilicid und Säuren entstehenden Siliciumwasserstoffe". Berichte der Deutschen Chemischen Gesellschaft 49: 111–157. doi:10.1002/cber.19160490114. https://zenodo.org/record/1426597. 
  4. Stock, Alfred; Stiebeler, Paul; Zeidler, Friedrich (1923). "Siliciumwasserstoffe, XVI.: Die höheren Siliciumhydride". Berichte der Deutschen Chemischen Gesellschaft (A and B Series) 56 (7): 1695–1705. doi:10.1002/cber.19230560735. 
  5. Vanderwielen, A. J.; Ring, M. A.; O'Neal, H. E. (1975). "Kinetics of the thermal decomposition of methyldisilane and trisilane". Journal of the American Chemical Society 97 (5): 993–998. doi:10.1021/ja00838a008. 
  6. United States Patent Application Publication. Pub No. US 2012/0252190 A1, OCT, 4, 2012. Zehavi et al.
  7. Heitsch, Andrew T.; Fanfair, Dayne D.; Tuan, Hsing-Yu; Korgel, Brian A. (2008). "Solution−Liquid−Solid (SLS) Growth of Silicon Nanowires". Journal of the American Chemical Society 130 (16): 5436–5437. doi:10.1021/ja8011353. PMID 18373344.