fbpx
Wikipedia

Bis(trimethylsilyl)amine

January 01, 1970

Bis(trimethylsilyl)amine (also known as hexamethyldisilazane and HMDS) is an organosilicon compound with the molecular formula [(CH3)3Si]2NH. The molecule is a derivative of ammonia with trimethylsilyl groups in place of two hydrogen atoms. An electron diffraction study shows that silicon-nitrogen bond length (173.5 pm) and Si-N-Si bond angle (125.5°) to be similar to disilazane (in which methyl groups are replaced by hydrogen atoms) suggesting that steric factors are not a factor in regulating angles in this case.[2] This colorless liquid is a reagent and a precursor to bases that are popular in organic synthesis and organometallic chemistry. Additionally, HMDS is also increasingly used as molecular precursor in chemical vapor deposition techniques to deposit silicon carbonitride thin films or coatings.

Bis(trimethylsilyl)amine
Structural formula of bis(trimethylsilyl)amine
Spacefill model of bis(trimethylsilyl)amine
Names
Preferred IUPAC name
1,1,1-Trimethyl-N-(trimethylsilyl)silanamine[1]
Other names
Bis(trimethylsilyl)azane
Bis(trimethylsilyl)amine
1,1,1,3,3,3-Hexamethyldisilazane
Hexamethyldisilazane
Identifiers
  • 999-97-3 Y
3D model (JSmol)
  • Interactive image
  • Interactive image
Abbreviations HMDS
635752
ChEBI
  • CHEBI:85068 N
ChemSpider
  • 13238 Y
ECHA InfoCard 100.012.425
EC Number
  • 213-668-5
MeSH Hexamethylsilazane
  • 13838
  • 18913873 amine
  • 45051731 sodium
  • 45051783 potassium
RTECS number
  • JM9230000
UNII
  • H36C68P1BH Y
UN number 2924, 3286
  • DTXSID2025395
  • InChI=1S/C6H19NSi2/c1-8(2,3)7-9(4,5)6/h7H,1-6H3 Y
    Key: FFUAGWLWBBFQJT-UHFFFAOYSA-N Y
  • InChI=1/C6H19NSi2/c1-8(2,3)7-9(4,5)6/h7H,1-6H3
    Key: FFUAGWLWBBFQJT-UHFFFAOYAF
  • C[Si](C)(C)N[Si](C)(C)C
  • N([Si](C)(C)C)[Si](C)(C)C
Properties
C6H19NSi2
Molar mass 161.395 g·mol−1
Appearance Colorless liquid
Density 0.77 g cm−3
Melting point −78 °C (−108 °F; 195 K)
Boiling point 126 °C (259 °F; 399 K)
Slow hydrolysis
1.4090
Hazards
NFPA 704 (fire diamond)
Health 3: Short exposure could cause serious temporary or residual injury. E.g. chlorine gasFlammability 3: Liquids and solids that can be ignited under almost all ambient temperature conditions. Flash point between 23 and 38 °C (73 and 100 °F). E.g. gasolineInstability 1: Normally stable, but can become unstable at elevated temperatures and pressures. E.g. calciumSpecial hazards (white): no code
3
3
1
Safety data sheet (SDS) External MSDS
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
N verify (what is YN ?)

Synthesis and derivatives edit

Bis(trimethylsilyl)amine is synthesized by treatment of trimethylsilyl chloride with ammonia:[3]

2 (CH3)3SiCl + 3 NH3 → [(CH3)3Si]2NH + 2 NH4Cl

Ammonium nitrate together with triethylamine can be used instead.[4] This method is also useful for 15N isotopic enrichment of HMDS.

 

Alkali metal bis(trimethylsilyl)amides result from the deprotonation of bis(trimethylsilyl)amine. For example, lithium bis(trimethylsilyl)amide (LiHMDS) is prepared using n-butyllithium:

[(CH3)3Si]2NH + BuLi → [(CH3)3Si]2NLi + BuH

LiHMDS and other similar derivatives: sodium bis(trimethylsilyl)amide (NaHMDS) and potassium bis(trimethylsilyl)amide (KHMDS) are used as a non-nucleophilic bases in synthetic organic chemistry.

Use as reagent edit

Hexamethyldisilazane is employed as a reagent in many organic reactions:

1) HMDS is used as a reagent in condensation reactions of heterocyclic compounds such as in the microwave synthesis of a derivative of xanthine:[5]

 

2) The HMDS mediated trimethylsilylation of alcohols, thiols, amines and amino acids as protective groups or for intermediary organosilicon compounds is found to be very efficient and replaced TMSCl reagent.[6]

Silylation of glutamic acid with excess hexamethyldisilazane and catalytic TMSCl in either refluxing xylene or acetonitrile followed by dilution with alcohol (methanol or ethanol) yields the derived lactam pyroglutamic acid in good yield.

 

HMDS in the presence of catalytic iodine facilitates the silylation of alcohols in excellent yields.

 

3) HMDS can be used to silylate laboratory glassware and make it hydrophobic, or automobile glass, just as Rain-X does.

4) In gas chromatography, HMDS can be used to silylate OH groups of organic compounds to increase volatility, this way enabling GC-analysis of chemicals that are otherwise non-volatile.

Other uses edit

In photolithography, HMDS is often used as an adhesion promoter for photoresists. Best results are obtained by applying HMDS from the gas phase on heated substrates.[7][8]

In electron microscopy, HMDS can be used as an alternative to critical point drying during sample preparation.[9]

In pyrolysis-gas chromatography-mass spectrometry, HMDS is added to the analyte to create silylated diagnostic products during pyrolysis, in order to enhance detectability of compounds with polar functional groups.[10]

In plasma-enhanced chemical vapor deposition (PECVD), HMDS is used as a molecular precursor as a replacement to highly flammable and corrosive gasses like SiH4, CH4, NH3 as it can be easily handled. HMDS is used in conjunction with a plasma of various gases such as argon, helium and nitrogen to deposit SiCN thin films/coatings with excellent mechanical, optical and electronic properties.[11]

See also edit

References edit

  1. ^ Nomenclature of Organic Chemistry : IUPAC Recommendations and Preferred Names 2013 (Blue Book). Cambridge: The Royal Society of Chemistry. 2014. p. 135. doi:10.1039/9781849733069-FP001. ISBN 978-0-85404-182-4.
  2. ^ D.A. Armitage (1982). "9.1 - Organosilanes". Organosilicon - an overview. Comprehensive Organometallic Chemistry. pp. 1–203. doi:10.1016/B978-008046518-0.00014-3. ISBN 9780080465180.
  3. ^ Robert C. Osthoff; Simon W. Kantor (1957). "Organosilazane Compounds". Inorganic Syntheses. Inorg. Synth. Vol. 5. pp. 55–64. doi:10.1002/9780470132364.ch16. ISBN 978-0-470-13236-4.
  4. ^ S.V. Chernyak; Yu. G. Yatluk; A.L. Suvorov (2000). "A Simple Synthesis of Hexamethyldisilazane (Translated from Zhurnal obshcheĭ khimiĭ, Vol. 70. No. 8, 2000. p1401)". Russian Journal of General Chemistry. 70: 1313.
  5. ^ 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. PMC 1698928. PMID 17067400.
  6. ^ Benjamin A. Anderson; Vikas Sikervar (2001). "Hexamethyldisilazane". Encyclopedia of Reagents for Organic Synthesis. doi:10.1002/047084289X.rh016. ISBN 0471936235.
  7. ^ Cornell NanoScale Science & Technology Facility. . Archived from the original on 2019-09-07. Retrieved 2008-01-29.
  8. ^ "YES Prime Oven | Stanford Nanofabrication Facility". snfexfab.stanford.edu. Stanford Nanofabrication Facility.
  9. ^ 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. S2CID 26050695.
  10. ^ Giuseppe Chiavari; Daniele Fabbri & Silvia Prati (2001). "Gas chromatographic–mass spectrometric analysis of products arising from pyrolysis of amino acids in the presence of hexamethyldisilazane". Journal of Chromatography A. 922 (1–2): 235–241. doi:10.1016/S0021-9673(01)00936-0. PMID 11486868.
  11. ^ P. Jedrzejowski; J. Cizek; A. Amassian; J. E. Klemberg-Sapieha; J. Vlcek; L. Martinu (2004). "Mechanical and optical properties of hard SiCN coatings prepared by PECVD". Thin Solid Films . 447–448: 201–207. Bibcode:2004TSF...447..201J. doi:10.1016/S0040-6090(03)01057-5.

January 01, 1970
trimethylsilyl, amine, also, known, hexamethyldisilazane, hmds, organosilicon, compound, with, molecular, formula, molecule, derivative, ammonia, with, trimethylsilyl, groups, place, hydrogen, atoms, electron, diffraction, study, shows, that, silicon, nitrogen. Bis trimethylsilyl amine also known as hexamethyldisilazane and HMDS is an organosilicon compound with the molecular formula CH3 3Si 2NH The molecule is a derivative of ammonia with trimethylsilyl groups in place of two hydrogen atoms An electron diffraction study shows that silicon nitrogen bond length 173 5 pm and Si N Si bond angle 125 5 to be similar to disilazane in which methyl groups are replaced by hydrogen atoms suggesting that steric factors are not a factor in regulating angles in this case 2 This colorless liquid is a reagent and a precursor to bases that are popular in organic synthesis and organometallic chemistry Additionally HMDS is also increasingly used as molecular precursor in chemical vapor deposition techniques to deposit silicon carbonitride thin films or coatings Bis trimethylsilyl amine Structural formula of bis trimethylsilyl amine Spacefill model of bis trimethylsilyl amine Names Preferred IUPAC name 1 1 1 Trimethyl N trimethylsilyl silanamine 1 Other names Bis trimethylsilyl azaneBis trimethylsilyl amine1 1 1 3 3 3 Hexamethyldisilazane Hexamethyldisilazane Identifiers CAS Number 999 97 3 Y 3D model JSmol Interactive imageInteractive image Abbreviations HMDS Beilstein Reference 635752 ChEBI CHEBI 85068 N ChemSpider 13238 Y ECHA InfoCard 100 012 425 EC Number 213 668 5 MeSH Hexamethylsilazane PubChem CID 1383818913873 amine45051731 sodium45051783 potassium RTECS number JM9230000 UNII H36C68P1BH Y UN number 2924 3286 CompTox Dashboard EPA DTXSID2025395 InChI InChI 1S C6H19NSi2 c1 8 2 3 7 9 4 5 6 h7H 1 6H3 YKey FFUAGWLWBBFQJT UHFFFAOYSA N YInChI 1 C6H19NSi2 c1 8 2 3 7 9 4 5 6 h7H 1 6H3Key FFUAGWLWBBFQJT UHFFFAOYAF SMILES C Si C C N Si C C CN Si C C C Si C C C Properties Chemical formula C 6H 19N Si 2 Molar mass 161 395 g mol 1 Appearance Colorless liquid Density 0 77 g cm 3 Melting point 78 C 108 F 195 K Boiling point 126 C 259 F 399 K Solubility in water Slow hydrolysis Refractive index nD 1 4090 Hazards NFPA 704 fire diamond 331 Safety data sheet SDS External MSDS Except where otherwise noted data are given for materials in their standard state at 25 C 77 F 100 kPa N verify what is Y N Infobox references Contents 1 Synthesis and derivatives 2 Use as reagent 3 Other uses 4 See also 5 ReferencesSynthesis and derivatives editBis trimethylsilyl amine is synthesized by treatment of trimethylsilyl chloride with ammonia 3 2 CH3 3SiCl 3 NH3 CH3 3Si 2NH 2 NH4Cl Ammonium nitrate together with triethylamine can be used instead 4 This method is also useful for 15N isotopic enrichment of HMDS nbsp Alkali metal bis trimethylsilyl amides result from the deprotonation of bis trimethylsilyl amine For example lithium bis trimethylsilyl amide LiHMDS is prepared using n butyllithium CH3 3Si 2NH BuLi CH3 3Si 2NLi BuH LiHMDS and other similar derivatives sodium bis trimethylsilyl amide NaHMDS and potassium bis trimethylsilyl amide KHMDS are used as a non nucleophilic bases in synthetic organic chemistry Use as reagent editHexamethyldisilazane is employed as a reagent in many organic reactions 1 HMDS is used as a reagent in condensation reactions of heterocyclic compounds such as in the microwave synthesis of a derivative of xanthine 5 nbsp 2 The HMDS mediated trimethylsilylation of alcohols thiols amines and amino acids as protective groups or for intermediary organosilicon compounds is found to be very efficient and replaced TMSCl reagent 6 Silylation of glutamic acid with excess hexamethyldisilazane and catalytic TMSCl in either refluxing xylene or acetonitrile followed by dilution with alcohol methanol or ethanol yields the derived lactam pyroglutamic acid in good yield nbsp HMDS in the presence of catalytic iodine facilitates the silylation of alcohols in excellent yields nbsp 3 HMDS can be used to silylate laboratory glassware and make it hydrophobic or automobile glass just as Rain X does 4 In gas chromatography HMDS can be used to silylate OH groups of organic compounds to increase volatility this way enabling GC analysis of chemicals that are otherwise non volatile Other uses editIn photolithography HMDS is often used as an adhesion promoter for photoresists Best results are obtained by applying HMDS from the gas phase on heated substrates 7 8 In electron microscopy HMDS can be used as an alternative to critical point drying during sample preparation 9 In pyrolysis gas chromatography mass spectrometry HMDS is added to the analyte to create silylated diagnostic products during pyrolysis in order to enhance detectability of compounds with polar functional groups 10 In plasma enhanced chemical vapor deposition PECVD HMDS is used as a molecular precursor as a replacement to highly flammable and corrosive gasses like SiH4 CH4 NH3 as it can be easily handled HMDS is used in conjunction with a plasma of various gases such as argon helium and nitrogen to deposit SiCN thin films coatings with excellent mechanical optical and electronic properties 11 See also editHexamethyldisiloxane Metal bis trimethylsilyl amidesReferences edit Nomenclature of Organic Chemistry IUPAC Recommendations and Preferred Names 2013 Blue Book Cambridge The Royal Society of Chemistry 2014 p 135 doi 10 1039 9781849733069 FP001 ISBN 978 0 85404 182 4 D A Armitage 1982 9 1 Organosilanes Organosilicon an overview Comprehensive Organometallic Chemistry pp 1 203 doi 10 1016 B978 008046518 0 00014 3 ISBN 9780080465180 Robert C Osthoff Simon W Kantor 1957 Organosilazane Compounds Inorganic Syntheses Inorg Synth Vol 5 pp 55 64 doi 10 1002 9780470132364 ch16 ISBN 978 0 470 13236 4 S V Chernyak Yu G Yatluk A L Suvorov 2000 A Simple Synthesis of Hexamethyldisilazane Translated from Zhurnal obshcheĭ khimiĭ Vol 70 No 8 2000 p1401 Russian Journal of General Chemistry 70 1313 Burbiel JC Hockemeyer J Muller 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 PMC 1698928 PMID 17067400 Benjamin A Anderson Vikas Sikervar 2001 Hexamethyldisilazane Encyclopedia of Reagents for Organic Synthesis doi 10 1002 047084289X rh016 ISBN 0471936235 Cornell NanoScale Science amp Technology Facility CNF Photolithography Resist Processes and Capabilities Archived from the original on 2019 09 07 Retrieved 2008 01 29 YES Prime Oven Stanford Nanofabrication Facility snfexfab stanford edu Stanford Nanofabrication Facility 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 S2CID 26050695 Giuseppe Chiavari Daniele Fabbri amp Silvia Prati 2001 Gas chromatographic mass spectrometric analysis of products arising from pyrolysis of amino acids in the presence of hexamethyldisilazane Journal of Chromatography A 922 1 2 235 241 doi 10 1016 S0021 9673 01 00936 0 PMID 11486868 P Jedrzejowski J Cizek A Amassian J E Klemberg Sapieha J Vlcek L Martinu 2004 Mechanical and optical properties of hard SiCN coatings prepared by PECVD Thin Solid Films 447 448 201 207 Bibcode 2004TSF 447 201J doi 10 1016 S0040 6090 03 01057 5 Retrieved from https en wikipedia org w index php title Bis trimethylsilyl amine amp oldid 1214846897, wikipedia, wiki, book, books, library,

article

, read, download, free, free download, mp3, video, mp4, 3gp, jpg, jpeg, gif, png, picture, music, song, movie, book, game, games.