- Silicon tetrafluoride
Chembox new
Name = Silicon tetrafluoride
ImageFile = Silicon-tetrafluoride-2D-dimensions.png
ImageName = Silicon tetrafluoride
ImageFile1 = Silicon-tetrafluoride-3D-vdW.png
ImageName1 = Silicon tetrafluoride
IUPACName = Silicon tetrafluoride
OtherNames = Tetrafluorosilane
Silicon fluoride
Fluoro acid air
Section1 = Chembox Identifiers
SMILES = FSi(F)(F)F
CASNo = 7783-61-1
RTECS = VW2327000
Section2 = Chembox Properties
Formula = SiF4
MolarMass = 104.08 g/mol
Appearance = colourless gas
( fuming in moist air)
Density = 1.66 g/cm3, solid (-95 C)
Solubility = hydrolysis
MeltingPt = -86 °C
BoilingPt = sublimes at -95.5 °C at 1 atm
Viscosity = ? cP at ?°C
Section3 = Chembox Structure
MolShape = tetrahedral
Dipole = 0 D
Section7 = Chembox Hazards
ExternalMSDS =
MainHazards = toxic, corrosive
RPhrases = 14-26/27/28-31-34
SPhrases = 23-26-36/37/39-45
Section8 = Chembox Related
OtherCpds = SiCl4
SiH4Dihydrogen hexafluorosilicate Silicon tetrafluoride or Tetrafluorosilane is the
chemical compound with the formula SiF4. This tetrahedral molecule is striking because it has a remarkably narrow liquid range (its boiling point is only 4 °C above its melting point). It was first synthesized by John Davy in 1812. [cite journal
title = An Account of Some Experiments on Different Combinations of Fluoric Acid
author = John Davy
journal =Philosophical Transactions of the Royal Society of London
year = 1812
volume = 102
issue =
pages = 352–369
url = http://links.jstor.org/sici?sici=0261-0523%281812%29102%3C352%3AAAOSEO%3E2.0.CO%3B2-4
doi = 10.1098/rstl.1812.0020]Preparation
SiF4 is a by-product of the production of
phosphate fertilizer s, resulting from the attack ofHF (derived fromfluoroapatite protonolysis) onsilicate s. In the laboratory, the compound is prepared by heating BaSiF6 >300 °C, whereupon the solid releases volatile SiF4, leaving a residue of BaF2. The required BaSiF6 is prepared by treating aqueous fluorosilicic acid withbarium chloride . [Hoffman, C. J.; Gutowsky, H. S. “Silicon Tetrafluoride” Inorganic Syntheses McGraw-Hill: New York, Volume 4, pages 145-6, 1953.] The corresponding GeF4 is prepared analogously, except that the thermal "cracking" requires 700 °C. [Hoffman, C. J.; Gutowsky, H. S. "Germanium Tetrafluoride” Inorganic Syntheses McGraw-Hill: New York, Volume 4, pages 147-8, 1953.]Uses
This volatile compound finds limited use in microelectronics and
organic synthesis . [Shimizu, M. "Silicon(IV) Fluoride" Encyclopedia of Reagents for Organic Synthesis, 2001 John Wiley & Sons. DOI: 10.1002/047084289X.rs011]Occurrence
Vulcanic plumes contain significant amounts of silicon tetrafluoride, the daily production can reach several tonnes per day. [cite journal
title = High SiF4/HF ratio detected in Satsuma-Iwojima volcano's plume by remote FT-IR observation
author = T. Mori, M. Sato, Y. Shimoike, K. Notsu
journal = Earth Planets Space
year = 2002
volume = 54
issue =
pages = 249–256
url = http://www.terrapub.co.jp/journals/EPS/pdf/2002/5403/54030249.pdf] The silicon tetrafluoride is partly hydrolysed and formshexafluorosilicic acid .References
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