Chemistry:Silicon tetraiodide
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| Names | |||
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| Other names
silicon tetraiodide
Tetraiodosilane | |||
| Identifiers | |||
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| 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) | ||
| reacts | |||
| Solubility in organic solvents | soluble | ||
| Structure | |||
| tetrahedral | |||
| Hazards | |||
| GHS pictograms |    
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| GHS Signal word | Danger | ||
| H301, H311, H314, H317, H334, H360 | |||
| P201, P202, P260, P261, P264, P270, P272, P280, P281, P285, P301+310, P301+330+331, P302+352, P303+361+353, P304+340, P304+341, P305+351+338, P308+313, P310, P312, P321, P322, P330, P333+313, P342+311 | |||
| NFPA 704 (fire diamond) | |||
| Related compounds | |||
Other anions
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Silicon tetrafluoride Silicon tetrachloride Silicon tetrabromide | ||
Other cations
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Carbon tetraiodide Germanium tetraiodide Tin(IV) iodide | ||
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). | |||
 verify (what is   ?)
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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.
Synthesis and reactions
This compound is produced by treating silicon-copper mixture with iodine:[3]
- Si + I
2 → SiI
4
It reacts quickly with water and moisture in the air.
It can also 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.[4] The last one can be readily distinguished from the similar carbon compound, iodoform which is a yellow solid at room temperature.
Comparison with other SiX4 compounds
| SiH4 | SiF4 | SiCl4 | SiBr4 | SiI4 | |
|---|---|---|---|---|---|
| b.p. (˚C)[5] | -111.9 | -90.3 | 56.8 | 155.0 | 290.0 |
| m.p. (˚C)[5] | -185 | -95.0 | -68.8 | 5.0 | 155.0 |
| Si-X bond length (Å) | >0.74 [6] | 1.55 | 2.02 | 2.20 | 2.43 |
| Si-X bond energy (kJ/mol)[7] | 384 | 582 | 391 | 310 | 234 |
References
- ↑ Kolonits, Maria; Hargittai, Magdolna (1998). "Molecular Structure of Silicon Tetraiodide". Structural Chemistry 9 (5): 349–352. doi:10.1023/A:1022462926682.
- ↑ 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.
- ↑ P. W. Schenk (1963). "Silicon and Germanium". in G. Brauer. Handbook of Preparative Inorganic Chemistry, 2nd Ed.. 2page=689. NY, NY: Academic Press.
- ↑ Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. ISBN 978-0-08-037941-8.
- ↑ 5.0 5.1 Silicon Compounds, Silicon Halides. Collins, W.: Kirk-Othmer Encyclopedia of Chemical Technology; John Wiley & Sons, Inc, 2001.
- ↑ "What is the bond length of the H-H bond?". https://www.answers.com/Q/What_is_the_bond_length_of_the_H-H_bond.
- ↑ Ebsworth, E. A. V. In Volatile Silicon Compounds; Taube, H.; Maddock, A. G.; Inorganic Chemistry; Pergamon Press Book: New York, NY, 1963; Vol. 4.
External links
| HI | He | ||||||||||||||||
| LiI | BeI2 | BI3 | CI4 | NI3 | I2O4, I2O5, I4O9 |
IF, IF3, IF5, IF7 |
Ne | ||||||||||
| NaI | MgI2 | AlI3 | SiI4 | PI3, P2I4 |
S | ICl, ICl3 |
Ar | ||||||||||
| KI | CaI2 | Sc | TiI4 | VI3 | CrI3 | MnI2 | FeI2 | CoI2 | NiI2 | CuI | ZnI2 | Ga2I6 | GeI2, GeI4 |
AsI3 | Se | IBr | Kr |
| RbI | SrI2 | YI3 | ZrI4 | NbI5 | Mo | Tc | Ru | Rh | Pd | AgI | CdI2 | InI3 | SnI4, SnI2 |
SbI3 | TeI4 | I | Xe |
| CsI | BaI2 | HfI4 | TaI5 | W | Re | Os | Ir | Pt | AuI | Hg2I2, HgI2 |
TlI | PbI2 | BiI3 | Po | AtI | Rn | |
| Fr | RaI2 | Rf | Db | Sg | Bh | Hs | Mt | Ds | Rg | Cn | Nh | Fl | Mc | Lv | Ts | Og | |
| ↓ | |||||||||||||||||
| La | Ce | Pr | Nd | Pm | SmI2 | Eu | Gd | TbI3 | Dy | Ho | Er | Tm | Yb | Lu | |||
| Ac | ThI4 | Pa | UI3, UI4 |
Np | Pu | Am | Cm | Bk | Cf | EsI3 | Fm | Md | No | Lr | |||
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