Bis(trimethylsilyl)amine

Chembox new
Name = Bis(trimethylsilyl)amine
Reference = ["Merck Index", 13th Edition, 4708.]
ImageFile1 = HMDS.png ImageFile2 = HMDS-3D.png ImageName = Bis(trimethylsilyl)amine
IUPACName = 1,1,1,3,3,3-Hexamethyldisilazane
OtherNames = Bis(trimethylsilyl)amine
Hexamethyldisilazane
Hexamethyldisilane
HMDS
Section1 = Chembox Identifiers
CASNo = 999-97-3
SMILES = C [Si] (C)(C)N [Si] (C)(C)C
Section2 = Chembox Properties
Formula = C₆H₁₉NSi₂
MolarMass = 161.40 g/mol
Density = 0.76 g/cm³
MeltingPt = -78 °C
BoilingPt = 125 °C
Section7 = Chembox Hazards
NFPA-H = 1
NFPA-F = 3
NFPA-R = 1
ExternalMSDS = [http://www.jtbaker.com/msds/englishhtml/h2066.htm External MSDS]

Bis(trimethylsilyl)amine (also known as hexamethyldisilazane, or HMDS) is a chemical reagent with the molecular formula (CH₃)₃Si-NH-Si(CH₃)₃ which consists of ammonia substituted with two trimethylsilyl functional groups. It is a clear, colorless liquid that will hydrolize slowly upon exposure to water.

Bis(trimethylsilyl)amide results from the deprotonation of the nitrogen atom of bis(trimethylsilyl)amines and are used as non-nucleophilic bases, including:

* Lithium bis(trimethylsilyl)amide (LiHMDS)
* Sodium bis(trimethylsilyl)amide (NaHMDS)
* Potassium bis(trimethylsilyl)amide (KHMDS)

Organic chemistry

One of the uses of HMDS is as a reagent in condensation reactions of heterocyclic compounds such as in the microwave synthesis of a derivative of xanthine: [cite journal |author=Burbiel JC, Hockemeyer J, Müller CE |title=Microwave-assisted ring closure reactions: synthesis of 8-substituted xanthine derivatives and related pyrimido- and diazepinopurinediones |journal=Beilstein J Org Chem |volume=2 |issue= |pages=20 |year=2006 |pmid=17067400 | url=http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=1698928 |doi=10.1186/1860-5397-2-20]

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Other

In photolithography, HMDS is often used in as an adhesion promoter for photoresist.Best results are obtained by applying HMDS from the gas phase on heated substrates. [cite web |url=http://www.cnf.cornell.edu/cnf_process_photo_resists.html#hmds |title=CNF - Photolithography Resist Processes and Capabilities |author = Cornell NanoScale Science & Technology Facility | accessdate=2008-01-29 ]

In electron microscopy, HMDS can be used as an alternative to critical point drying during sample preparation. [cite journal |author=Bray DF, Bagu J, Koegler P |title=Comparison of hexamethyldisilazane (HMDS), Peldri II, and critical-point drying methods for scanning electron microscopy of biological specimens |journal=Microsc. Res. Tech. |volume=26 |issue=6 |pages=489–95 |year=1993 |pmid=8305726 |doi=10.1002/jemt.1070260603]

ee also

*Hexamethyldisiloxane

References