Lithium bis (trimethylsilyl) amide

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Structural formula
Structural formula of lithium bis (trimethylsilyl) amide
General
Surname Lithium bis (trimethylsilyl) amide
other names
  • LHMDS
  • Lithium hexamethyl disilazide
  • Bis (trimethylsilyl) lithium amide
Molecular formula C 6 H 18 LiNSi 2
Brief description

colorless to yellow solid

External identifiers / databases
CAS number 4039-32-1
EC number 223-725-6
ECHA InfoCard 100,021,569
PubChem 2733832
Wikidata Q219037
properties
Molar mass 167.33 g mol −1
Physical state

firmly

density

0.86 g cm −3

Melting point

83-86 ° C

solubility

reacts with water and alcohols

safety instructions
GHS labeling of hazardous substances
02 - Highly / extremely flammable 05 - Corrosive

danger

H and P phrases H: 228-314-318
P: 210-280-305 + 351 + 338-309-310-402
As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Lithium bis (trimethylsilyl) amide is a chemical compound from the group of trimethylsilylamides . It is the lithium salt of hexamethyldisilazane .

Extraction and presentation

Lithium bis (trimethylsilyl) amide can be obtained by reacting a solution of n-butyllithium in pentane with a solution of hexamethyldisilazane in ether .

properties

Lithium bis (trimethylsilyl) amide is a colorless solid that decomposes in air, whereby spontaneous ignition can occur. It is stable under nitrogen. As a solid, it is present as a trimer. It is soluble in many organic solvents and is in solution in THF or ether as a dimeric monomer mixture. In hydrocarbons it is present as a tetramer-dimer mixture. With halides it forms hexamethyldisilylamine derivatives.

use

Lithium bis (trimethylsilyl) amide is used as a base for the production of dienes and enolates . It is also used catalytically for the addition of phosphine PH bonds to the carbodiimides to form phosphaguanidines and the synthesis of disubstituted 1,2,5- thiadiazoles .

Individual evidence

  1. a b c d e f g data sheet lithium bis (trimethylsilyl) amide from AlfaAesar, accessed on January 13, 2014 ( PDF )(JavaScript required) .
  2. a b data sheet lithium bis (trimethylsilyl) amide, 97% from Sigma-Aldrich , accessed on January 13, 2014 ( PDF ).
  3. a b c Georg Brauer , with the assistance of Marianne Baudler a . a. (Ed.): Handbook of Preparative Inorganic Chemistry . 3rd, revised edition. tape I . Ferdinand Enke, Stuttgart 1975, ISBN 3-432-02328-6 , pp. 711 .
  4. Philip L. Fuchs: Handbook of Reagents for Organic Synthesis, Reagents for Silicon-Mediated ... John Wiley & Sons, 2013, ISBN 978-1-118-63613-8 , pp. 356 ( limited preview in Google Book Search).