Chemistry:Trisilane

Trisilane
Names
	IUPAC name Trisilane
Identifiers
CAS Number	7783-26-8 ;
3D model (JSmol)	Interactive image;
ChemSpider	122661 ;
EC Number	616-514-9;
PubChem CID	139070;
UNII	1T3A75Z4ZL ;
UN number	3194
	InChI InChI=1S/H8Si3/c1-3-2/h3H2,1-2H3 Key: VEDJZFSRVVQBIL-UHFFFAOYSA-N ;
	SMILES [SiH3] [SiH2] [SiH3];
Properties
Chemical formula	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)
Solubility in water	Slowly decomposes
Vapor pressure	12.7 kPa
Hazards
Main hazards	Pyrophoric
GHS pictograms
GHS Signal word	Danger
GHS hazard statements	H250, H261, H315, H319, H335
GHS precautionary statements	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)
Autoignition; temperature	< 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. In 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

↑ Alfred Walter Stewart (1926) (in English). Recent Advances in Physical and Inorganic Chemistry. Longmans, Green and Company, Limited. pp. 312. https://books.google.com/books?id=o3MVAQAAIAAJ. Retrieved 11 May 2021.
↑ ^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.
↑ 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.
↑ 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.
↑ 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.
↑ United States Patent Application Publication. Pub No. US 2012/0252190 A1, OCT, 4, 2012. Zehavi et al.
↑ 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.