Tris(trimethylsilyl)amine

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Tris(trimethylsilyl)amine
Tris(trimethylsilyl)amin Strukturformel.svg
Names
Preferred IUPAC name
1,1,1-Trimethyl-N,N-bis(trimethylsilyl)silanamine
Identifiers
3D model (JSmol)
ChemSpider
ECHA InfoCard 100.014.951 OOjs UI icon edit-ltr-progressive.svg
EC Number
  • 216-445-0
PubChem CID
UNII
  • InChI=1S/C9H27NSi3/c1-11(2,3)10(12(4,5)6)13(7,8)9/h1-9H3
    Key: PEGHITPVRNZWSI-UHFFFAOYSA-N
  • C[Si](C)(C)N([Si](C)(C)C)[Si](C)(C)C
Properties
C9H27NSi3
Molar mass 233.57g/mol
AppearanceWaxy solid
Melting point 67–69°C
Boiling point 215°C (85°C at 13mmHg)
Solubility Nonpolar organic solvents
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

Tris(trimethylsilyl)amine is the simplest tris(trialkylsilyl)amine which are having the general formula (R3Si)3N, in which all three hydrogen atoms of the ammonia are replaced by trimethylsilyl groups (-Si(CH3)3). [1] Tris(trimethylsilyl)amine has been for years in the center of scientific interest as a stable intermediate in chemical nitrogen fixation (i. e. the conversion of atmospheric nitrogen N2 into organic substrates under normal conditions). [2] [3] [4]

Contents

Production

Early attempts to prepare tris(trimethylsilyl)amine from ammonia and trimethylchlorosilane (TMS-Cl) were unsuccessful even at temperatures of 500 °C and in the presence of the base pyridine. [5] [6] The reaction of ammonia and trimethylchlorosilane stops at the stage of the doubly silylated product bis(trimethylsilyl)amine (usually referred to as hexamethyldisilazane, HMDS).

Synthese von Hexamethyldisilazan (HMDS) HMDS-Synthese.svg
Synthese von Hexamethyldisilazan (HMDS)

Tris(trimethylsilyl)amine is obtained by reaction of the sodium salt of hexamethyldisilazane - from hexamethyldisilazane and sodium amide [7] or from hexamethyldisilazane, sodium and styrene [1] - with trimethylchlorosilane in 80% yield. [8]

The lithium salt of hexamethyldisilazane - from hexamethyldisilazane and butyllithium [9] or from hexamethyldisilazane and phenyllithium [8] - reacts with trimethylchlorosilane only in yields of 50-60% to tris(trimethylsilyl)amine.

The reaction of lithium nitride with trimethylchlorosilane can be carried out as a one-pot reaction in THF with 72% yield. [10]

Properties

Tris(trimethylsilyl)amine is a colorless, crystalline [11] [12] or waxy [7] solid which is stable to water and bases. [13] Alcohols or acids though cleave the Si-N-bond under formation of ammonia. [7]

Applications

Tris(trimethylsilyl)amine as a synthetic building block

From antimony trichloride and tris(trimethylsilyl)amine, a nitridoantimone cubane-type cluster can be formed almost quantitatively at –60 °C. [14]

Ketones can be trifluoromethylated in the presence of P4-t-Bu and nonamethyltrisilazane under mild conditions in yields of up to 84% with the inert fluoroform (HCF3, HFC-23). [15]

The monomer trichloro(trimethylsilyl)-phosphoranimine Cl3P=NSiMe3 is formed from tris(trimethylsilyl)amine and phosphorus pentachloride in hexane at 0 °C,

Synthese von Trichlor(trimethylsilyl)phosphoranimin Synthese von Trichlor(trimethylsilyl)phosphoranimin.svg
Synthese von Trichlor(trimethylsilyl)phosphoranimin

which can be polymerized to linear polydichlorophosphazenes with defined molecular weights and polydispersities. [16]

The cyclic trimer (NPCl2)3 hexachlorocyclotriphosphane is predominantly formed from tris(trimethylsilyl)amine and phosphorus pentachloride in boiling dichloromethane (about 40 °C) among other oligomers which gives upon heating over 250 °C high molecular weight, little defined polydichlorophosphazenes.

Synthese von Hexachlorcyclotriphosphan Synthese von Hexachlorcyclotriphosphan.svg
Synthese von Hexachlorcyclotriphosphan

Nitrogen trifluoride NF3 (which is used, inter alia, for the plasma etching of silicon wafers) is obtainable from tris(trimethylsilyl)amine and fluorine at –40 °C in acetonitrile, suppressing the formation of nitrogen and tetrafluorohydrazine, which are produced as undesirable by-products during the standard synthesis of nitrogen trifluoride from ammonia or ammonium fluoride. [17]

Synthese von NF3 Bildung von Stickstofftrifluorid.svg
Synthese von NF3

Tris(trimethylsilyl)amine intermediate in chemical nitrogen fixation

The technical nitrogen fixation was made possible by the Haber-Bosch process, in which nitrogen is converted into ammonia by reductive protonation in the presence of iron catalysts under high pressures (> 150 bar) and temperatures (> 400 °C). In chemical nitrogen fixation (i.e., the transformation of atmospheric nitrogen under normal conditions into reactive starting materials for chemical syntheses, usually also ammonia), tris(trimethylsilyl)amine plays an important role in the so-called reductive silylation, since it is hydrolyzed with water to ammonia.

As early as 1895 it was observed that metallic lithium reacts with nitrogen to lithium nitride at room temperature. [18] In 1972, K. Shiina observed that lithium (as an electron donor) forms with trimethylsilyl chloride under darkening tris(trimethylsilyl)amine in the presence of chromium(III) chloride as a catalyst at room temperature with the nitrogen used for inerting. [2]

More recently, for the reductive silylation of N2, sodium has been used instead of lithium as the electron donor and molybdenum [19] and iron compounds [3] (such as pentacarbonyl iron or ferrocenes [20] ) as catalysts, up to 34 equivalents of N(Me3Si)3 could be obtained per iron atom in the catalyst.

With a molybdenum-ferrocene complex as catalyst, a turnover number of up to 226 could be achieved. [21]

The catalytic productivity of the catalysts for chemical nitrogen fixation developed so far is, despite intensive research, [22] still by magnitude smaller than, for example, the modern polymerization catalysts of the metallocene type or enzymes.

Related Research Articles

<span class="mw-page-title-main">Ammonium</span> Polyatomic ion (NH₄, charge +1)

The ammonium cation is a positively-charged polyatomic ion with the chemical formula NH+4 or [NH4]+. It is formed by the protonation of ammonia. Ammonium is also a general name for positively charged or protonated substituted amines and quaternary ammonium cations, where one or more hydrogen atoms are replaced by organic groups.

<span class="mw-page-title-main">Base (chemistry)</span> Type of chemical substance

In chemistry, there are three definitions in common use of the word base, known as Arrhenius bases, Brønsted bases, and Lewis bases. All definitions agree that bases are substances that react with acids, as originally proposed by G.-F. Rouelle in the mid-18th century.

<span class="mw-page-title-main">Dinitrogen pentoxide</span> Chemical compound

Dinitrogen pentoxide is the chemical compound with the formula N2O5. It is one of the binary nitrogen oxides, a family of compounds that only contain nitrogen and oxygen. It exists as colourless crystals that sublime slightly above room temperature, yielding a colorless gas.

In organic chemistry, a nitrile is any organic compound that has a −C≡N functional group. The prefix cyano- is used interchangeably with the term nitrile in industrial literature. Nitriles are found in many useful compounds, including methyl cyanoacrylate, used in super glue, and nitrile rubber, a nitrile-containing polymer used in latex-free laboratory and medical gloves. Nitrile rubber is also widely used as automotive and other seals since it is resistant to fuels and oils. Organic compounds containing multiple nitrile groups are known as cyanocarbons.

Cyclopropene is an organic compound with the formula C3H4. It is the simplest cycloalkene. Because the ring is highly strained, cyclopropene is difficult to prepare and highly reactive. This colorless gas has been the subject for many fundamental studies of bonding and reactivity. It does not occur naturally, but derivatives are known in some fatty acids. Derivatives of cyclopropene are used commercially to control ripening of some fruit.

<span class="mw-page-title-main">Europium(III) chloride</span> Chemical compound

Europium(III) chloride is an inorganic compound with the formula EuCl3. The anhydrous compound is a yellow solid. Being hygroscopic it rapidly absorbs water to form a white crystalline hexahydrate, EuCl3·6H2O, which is colourless. The compound is used in research.

<span class="mw-page-title-main">Trimethylsilyl group</span> Functional group

A trimethylsilyl group (abbreviated TMS) is a functional group in organic chemistry. This group consists of three methyl groups bonded to a silicon atom [−Si(CH3)3], which is in turn bonded to the rest of a molecule. This structural group is characterized by chemical inertness and a large molecular volume, which makes it useful in a number of applications.

<span class="mw-page-title-main">Trimethylsilyl chloride</span> Chemical compound

Trimethylsilyl chloride, also known as chlorotrimethylsilane is an organosilicon compound (silyl halide), with the formula (CH3)3SiCl, often abbreviated Me3SiCl or TMSCl. It is a colourless volatile liquid that is stable in the absence of water. It is widely used in organic chemistry.

Ethylamine, also known as ethanamine, is an organic compound with the formula CH3CH2NH2. This colourless gas has a strong ammonia-like odor. It condenses just below room temperature to a liquid miscible with virtually all solvents. It is a nucleophilic base, as is typical for amines. Ethylamine is widely used in chemical industry and organic synthesis.

<span class="mw-page-title-main">Organosilicon chemistry</span> Organometallic compound containing carbon–silicon bonds

Organosilicon chemistry is the science of the preparation and properties of organosilicon compounds, which are organometallic compounds containing carbon–silicon bonds. Most organosilicon compounds are similar to the ordinary organic compounds, being colourless, flammable, hydrophobic, and stable to air. Silicon carbide is an inorganic compound.

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. 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.

The reduction of nitro compounds are chemical reactions of wide interest in organic chemistry. The conversion can be effected by many reagents. The nitro group was one of the first functional groups to be reduced. Alkyl and aryl nitro compounds behave differently. Most useful is the reduction of aryl nitro compounds.

<span class="mw-page-title-main">Lithium bis(trimethylsilyl)amide</span> Chemical compound

Lithium bis(trimethylsilyl)amide is a lithiated organosilicon compound with the formula LiN(Si(CH3)3)2. It is commonly abbreviated as LiHMDS or Li(HMDS) (lithium hexamethyldisilazide - a reference to its conjugate acid HMDS) and is primarily used as a strong non-nucleophilic base and as a ligand. Like many lithium reagents, it has a tendency to aggregate and will form a cyclic trimer in the absence of coordinating species.

<span class="mw-page-title-main">Tetrakis(hydroxymethyl)phosphonium chloride</span> Chemical compound

Tetrakis(hydroxymethyl)phosphonium chloride (THPC) is an organophosphorus compound with the chemical formula [P(CH2OH)4]Cl. The cation P(CH2OH)4+ is four-coordinate, as is typical for phosphonium salts. THPC has applications as a precursor to fire-retardant materials, as well as a microbiocide in commercial and industrial water systems.

Silylation is the introduction of one or more (usually) substituted silyl groups (R3Si) to a molecule. The process is the basis of organosilicon chemistry.

Organosodium chemistry is the chemistry of organometallic compounds containing a carbon to sodium chemical bond. The application of organosodium compounds in chemistry is limited in part due to competition from organolithium compounds, which are commercially available and exhibit more convenient reactivity.

<span class="mw-page-title-main">Metal bis(trimethylsilyl)amides</span>

Metal bis(trimethylsilyl)amides are coordination complexes composed of a cationic metal with anionic bis(trimethylsilyl)amide ligands and are part of a broader category of metal amides.

<span class="mw-page-title-main">Metal amides</span>

Metal amides (systematic name metal azanides) are a class of coordination compounds composed of a metal center with amide ligands of the form NR2−. Amide ligands have two electron pairs available for bonding. In principle, they can be terminal or bridging. In these two examples, the dimethylamido ligands are both bridging and terminal:

<span class="mw-page-title-main">Tris(trimethylsilyl)phosphine</span> Chemical compound

Tris(trimethylsilyl)phosphine is the organophosphorus compound with the formula P(SiMe3)3 (Me = methyl). It is a colorless liquid that ignites in air and hydrolyses readily.

<span class="mw-page-title-main">Abiological nitrogen fixation using homogeneous catalysts</span> Chemical process that converts nitrogen to ammonia

Abiological nitrogen fixation describes chemical processes that fix (react with) N2, usually with the goal of generating ammonia. The dominant technology for abiological nitrogen fixation is the Haber process, which uses an iron-based heterogeneous catalysts and H2 to convert N2 to NH3. This article focuses on homogeneous (soluble) catalysts for the same or similar conversions.

References

  1. 1 2 J. Goubeau, J. Jiminéz-Barberá (1960), "Tris-(trimethylsilyl)-amin", ZAAC (in German), vol. 303, no. 5–6, pp. 217–226, doi:10.1002/zaac.19603030502
  2. 1 2 K. Shiina (1972), "Reductive silylation of molecular nitrogen via fixation to tris(trimethylsilyl)amine", J. Am. Chem. Soc. , vol. 94, no. 26, pp. 9266–9267, doi:10.1021/ja00781a068
  3. 1 2 K.C. MacLeod, P.L. Holland (2013), "Recent developments in the homogeneous reduction of dinitrogen by molybdenum and iron", Nature Chemistry, vol. 5, no. 7, pp. 559–565, Bibcode:2013NatCh...5..559M, doi:10.1038/nchem.1620, PMC   3868624 , PMID   23787744
  4. ↑ W.I. Dzik (2016), "Silylation of dinitrogen catalyzed by hydridodinitrogen(triphenylphosphine) cobalt (I)", Inorganics, vol. 4, no. 3, p. 21, doi: 10.3390/inorganics4030021
  5. ↑ R.O. Sauer (1944), "Derivatives of the methylchlorosilanes. I. Trimethylsilanol and its simple ethers", J. Am. Chem. Soc. , vol. 66, no. 10, pp. 1707–1710, doi:10.1021/ja01238a030
  6. ↑ R.O. Sauer, R.H. Hasek (1946), "Derivatives of the methylchlorosilanes. IV. Amines", J. Am. Chem. Soc. , vol. 68, no. 2, pp. 241–244, doi:10.1021/ja01206a028
  7. 1 2 3 C.R. Krüger, H. Niederprüm, M. Schmidt, O. Scherer (1966), H.F. Holtzlow (ed.), Sodium Bis(trimethylsilyl)amide and Tris(trimethylsilyl)amine, in Inorganic Syntheses, vol. 8, Hoboken, NJ, USA: John Wiley & Sons, Inc., pp. 15–19, doi:10.1002/9780470132395.ch5, ISBN   9780470131671 {{citation}}: CS1 maint: multiple names: authors list (link)
  8. 1 2 U. Wannagat, H. Niederprüm (1961), "Beiträge zur Chemie der Silicium-Stickstoff-Verbindungen, XIII. Silylsubstituierte Alkaliamide", Chem. Ber. (in German), vol. 94, no. 6, pp. 1540–1547, doi:10.1002/cber.19610940618
  9. ↑ E.H. Amonoo-Neizer, R.A. Shaw, D.O. Skovlin, B.C. Smith, J.W. Rosenthal, W.L. Jolly (1966), H.F. Holtzlow (ed.), Lithium Bis(trimethylsilyl)amide and Tris(trimethylsilyl)amine, in Inorganic Syntheses, vol. 8, Hoboken, NJ, USA: John Wiley & Sons, Inc., pp. 19–22, doi:10.1002/9780470132395.ch5, ISBN   9780470131671 {{citation}}: CS1 maint: multiple names: authors list (link)
  10. ↑ W.L. Lehn (1964), "Preparation of tris(trimethylsilyl)- and tris(trimethylstannyl)amines", J. Am. Chem. Soc. , vol. 86, no. 2, p. 305, doi:10.1021/ja01056a057
  11. ↑ Sigma-Aldrich Co. , product no. {{{id}}} .
  12. ↑ Nonamethyltrisilazane at AlfaAesar, accessed on 28. Dezember 2016 ( PDF ) (JavaScript required).
  13. ↑ U. Wannagat, H. Niederprüm (1961), "dreifach silylierte Amine", ZAAC (in German), vol. 308, no. 1–6, pp. 337–351, doi:10.1002/zaac.19613080135
  14. ↑ M. Rhiel, F. Weller, J. Pebler, K. Dehnicke (1994), "[SbN(SbCl)3(NSbCl2)(NSiMe3)3·SbCl3], ein ungewöhnlicher Nitridoantimonkomplex mit Heterocubanstruktur", Angew. Chem. (in German), vol. 106, no. 5, pp. 599–600, Bibcode:1994AngCh.106..599R, doi:10.1002/ange.19941060519 {{citation}}: CS1 maint: multiple names: authors list (link)
  15. ↑ S. Okusu, K. Hirano, E. Tokunaga, N. Shibata (2015), "Organocatalyzed trifluormethylation of ketones and sulfonyl fluorides by fluoroform under a superbase system", ChemistryOpen , vol. 4, no. 5, pp. 581–585, doi:10.1002/open.201500160, PMC   4608523 , PMID   26491635 {{citation}}: CS1 maint: multiple names: authors list (link)
  16. ↑ US 5698664,H.R. Allcock, C.T. Morrissey, I. Manners, C.H. Honeyman,"Synthesis of polyphosphazenes with controlled molecular weight and polydispersity",published 1997-12-16, assigned to The Penn State Research Foundation, University of Toronto
  17. ↑ US 8163262,B. A. Omotowa,"Method for production of nitrogen fluoride from trimethylsilylamines",published 2012-4-24
  18. ↑ H. Deslandres (1895), "Absorption de l'azote par le lithium à froid", Comptes rendus, vol. 121, pp. 886–887
  19. ↑ Q. Liao, N. Saffon-Merceron, N. Mézailles (2015), "N2 reduction into silylamine at tridentate phosphine/Mo center: catalysis and mechanistic study", ACS Catal., vol. 5, no. 11, pp. 6902–6906, doi:10.1021/acscatal.5b01626 {{citation}}: CS1 maint: multiple names: authors list (link)
  20. ↑ M. Yuki, H. Tanaka, K. Sasaki, Y. Miyake, K. Yoshizawa, Y. Nishibayashi (2012), "Iron-catalyzed transformation of molecular dinitrogen into silylamine under ambient conditions", Nature Communications, vol. 3, p. 1254, Bibcode:2012NatCo...3.1254Y, doi: 10.1038/ncomms2264 , PMID   23212383 {{citation}}: CS1 maint: multiple names: authors list (link)
  21. ↑ H. Tanaka; et al. (2011), "Molybdenum-Catalyzed Transformation of Molecular Dinitrogen into Silylamine: Experimental and DFT Study on the Remarkable Role of Ferrocenyldiphosphine Ligands", J. Am. Chem. Soc. , vol. 133, no. 10, pp. 3498–3506, doi:10.1021/ja109181n, PMID   21341772
  22. ↑ Y. Nishibayashi (2015), "Recent progress in transition-metal-catalyzed reduction of molecular dinitrogen under ambient reaction conditions", Inorg. Chem. , vol. 54, no. 19, pp. 9234–9247, doi:10.1021/acs.inorgchem.5b00881, PMID   26131967
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