Stereo structural formula of trisilane with implicit hydrogens
Ball and stick model of trisilane
IUPAC name
  • 7783-26-8 checkY
3D model (JSmol)
  • Interactive image
  • 122661 checkY
ECHA InfoCard 100.132.113 Edit this at Wikidata
EC Number
  • 616-514-9
  • 139070
  • 1T3A75Z4ZL checkY
UN number 3194
  • DTXSID80884426 Edit this at Wikidata
  • InChI=1S/H8Si3/c1-3-2/h3H2,1-2H3 checkY
  • [SiH3][SiH2][SiH3]
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
Occupational safety and health (OHS/OSH):
Main hazards
GHS labelling:
GHS02: FlammableGHS07: Exclamation mark
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
Related compounds
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]


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]


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]


  1. ^ Alfred Walter Stewart (1926). Recent Advances in Physical and Inorganic Chemistry. Longmans, Green and Company, Limited. p. 312. Retrieved 11 May 2021.
  2. ^ a b P. W. Schenk (1963). "Silanes". In G. Brauer (ed.). Handbook of Preparative Inorganic Chemistry, 2nd Ed. Vol. 1. NY, NY: Academic Press. p. 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.
  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.