Bis(trimethylsilyl)amine
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| Names | |
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| IUPAC name
1,1,1,3,3,3-Hexamethyldisilazane
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| Other names
Bis(trimethylsilyl)amine
Hexamethyldisilazane Hexamethyldisilane HMDS | |
| Identifiers | |
3D model (JSmol)
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| ECHA InfoCard | 100.012.425 |
CompTox Dashboard (EPA)
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| Properties | |
| C6H19NSi2 | |
| Molar mass | 161.40 g/mol |
| Density | 0.76 g/cm3 |
| Melting point | -78 °C |
| Boiling point | 125 °C |
| Hazards | |
| NFPA 704 (fire diamond) | |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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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 hydrolyze 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:[2]
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.[3]
In electron microscopy, HMDS can be used as an alternative to critical point drying during sample preparation.[4]
See also
References
- ^ Merck Index, 13th Edition, 4708.
- ^ Burbiel JC, Hockemeyer J, Müller CE (2006). "Microwave-assisted ring closure reactions: synthesis of 8-substituted xanthine derivatives and related pyrimido- and diazepinopurinediones". Beilstein J Org Chem. 2: 20. doi:10.1186/1860-5397-2-20. PMID 17067400.
{{cite journal}}: CS1 maint: multiple names: authors list (link) CS1 maint: unflagged free DOI (link) - ^ Cornell NanoScale Science & Technology Facility. "CNF - Photolithography Resist Processes and Capabilities". Retrieved 2008-01-29.
- ^ Bray DF, Bagu J, Koegler P (1993). "Comparison of hexamethyldisilazane (HMDS), Peldri II, and critical-point drying methods for scanning electron microscopy of biological specimens". Microsc. Res. Tech. 26 (6): 489–95. doi:10.1002/jemt.1070260603. PMID 8305726.
{{cite journal}}: CS1 maint: multiple names: authors list (link)