Silicon tetraiodide

Silicon tetraiodide
Names
Other names
silicon tetraiodide
Tetraiodosilane
Identifiers
13465-84-4
ChemSpider 75335 Yes
Jmol-3D images Image
PubChem 83498
Properties
SiI4
Molar mass 535.7034 g/mol
Appearance white powder
Density 4.198 g/cm3
Melting point 120.5 °C (248.9 °F; 393.6 K)
Boiling point 287.4 °C (549.3 °F; 560.5 K)
insoluble
Solubility in organic solvents soluble
Structure
Molecular shape tetrahedral
Hazards
EU classification not listed
R-phrases R61-R24/25-R34-R42/43
S-phrases S53-S26-S36/37/39-S45
NFPA 704
Flammability code 0: Will not burn. E.g., water Health code 2: Intense or continued but not chronic exposure could cause temporary incapacitation or possible residual injury. E.g., chloroform Reactivity code 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g., liquid nitrogen Special hazards (white): no codeNFPA 704 four-colored diamond
0
2
0
Flash point −18 °C (0 °F; 255 K)
Except where noted otherwise, data is given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
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Infobox references

Silicon tetraiodide is the chemical compound with the formula SiI4. It is a tetrahedral molecule with Si-I bond lengths of 2.432(5) Å.[1]

SiI4 is a precursor to silicon amides of the formula Si(NR2)4 (R = alkyl).[2] It has also been of interest in the manufacture and etching of silicon in microelectronics.

Reactions

The compound is stable to strong heating and can be stored for long periods at room temperature but must be kept dry as it reacts quickly with water and also reacts slowly with moisture in the air in a similar way to silicon tetrachloride. It can be made on a large scale by reaction of silicon or silicon carbide with iodine on heating to about 200 °C. Of more academic interest is the reaction of silane with iodine vapour at 130 - 150 °C, as this produces a series of compounds ranging from iodosilane SiH3I to diiodosilane SiH2I2 and triiodosilane SiHI3 as well. These compounds are colourless liquids at room temperature. [3]The last one can be readily distinguished from the similar carbon compound, iodoform which is a yellow solid at room temperature.

References

  1. Kolonits, Maria; Hargittai, Magdolna (1998). Structural Chemistry 9 (5): 349. doi:10.1023/A:1022462926682. Missing or empty |title= (help)
  2. Banerjee, Chiranjib; Wade, Casey R.; Soulet, Axel; Jursich, Gregory; McAndrew, James; Belot, John A. (2006). "Direct syntheses and complete characterization of halide-free tetrakis(dialkylamino)silanes". Inorganic Chemistry Communications 9 (7): 761. doi:10.1016/j.inoche.2006.04.027.
  3. Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. ISBN 0080379419.

External links