Trimethylsilyl iodide

Trimethylsilyl iodide

Names
IUPAC name Iodo(trimethyl)silane
Identifiers
CAS Registry Number	16029-98-4
ChemSpider	76879
InChI InChI=1S/C3H9ISi/c1-5(2,3)4/h1-3H3 Key: CSRZQMIRAZTJOY-UHFFFAOYSA-N InChI=1/C3H9ISi/c1-5(2,3)4/h1-3H3 Key: CSRZQMIRAZTJOY-UHFFFAOYAB
Jmol-3D images	Image
PubChem	85247
SMILES I[Si](C)(C)C
Properties
Molecular formula	C3H9ISi
Molar mass	200.09 g·mol−1
Density	1.406 g/mL at 25 °C
Boiling point	106 °C (223 °F; 379 K)
Except where noted otherwise, data is given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
Infobox references

Iodotrimethylsilane, (CH₃)₃SiI, or the more confusing Trimethylsilyl iodide, is an organosilicon compound. It is a colorless, volatile liquid at room temperature.

Preparation

Trimethylsilyl iodide may be prepared by the oxidative cleavage of hexamethyldisilane by iodine,^[1] or by the cleavage of hexamethyldisiloxane with aluminium triiodide.^[1][2]

TMS-TMS + I₂ → 2 TMSI (TMS = (CH₃)₃Si)

TMS-O-TMS + AlI₃ → 2 TMSI + "AlIO"

Applications

Trimethylsilyl iodide is used to introduce the trimethylsilyl group onto alcohols (ROH):

ROH + TMSI → RO(TMS) + HI

This type of reaction may be useful for gas chromatography analysis; the resultant silyl ether is more volatile than the underivatized original materials.^[3]

For the preparation of bulk trimethylsilylated material, trimethylsilyl chloride may be preferred due to its lower cost.

References

1. ↑ 1.0 1.1 Olah, G.; Narang, S.C. (1982). "Iodotrimethylsilane—a versatile synthetic reagent". Tetrahedron 38 (15): 2225. doi:10.1016/0040-4020(82)87002-6. 
2. ↑ Michael E. Jung; Mark A. Lyster (1988). "Cleavage of Methyl Ethers with Iodotrimethylsilane: Cyclohexanol from Cyclohexyl Methyl Ether". Org. Synth. ; Coll. Vol. 6, p. 353 
3. ↑ http://www.chem.agilent.com/Library/applications/gcms59_opiates_urine.pdf