Potassium bis(trimethylsilyl)amide

Summary

Potassium bis(trimethylsilyl)amide (commonly abbreviated as KHMDS, Potassium(K) HexaMethylDiSilazide) is the chemical compound with the formula ((CH3)3Si)2NK. It is a strong, non-nucleophilic base with an approximate pKa of 26 (compare to lithium diisopropylamide, at 36).[citation needed]

Potassium bis(trimethylsilyl)amide
Stereo, skeletal formula of potassium bis(trimethylsilyl)amide dimer
Ball and stick model of potassium bis(trimethylsilyl)amide dimer
Names
Preferred IUPAC name
Potassium 1,1,1-trimethyl-N-(trimethylsilyl)silanaminide
Other names
Potassium hexamethyldisilazide[citation needed]
Identifiers
  • 40949-94-8 checkY
3D model (JSmol)
  • Interactive image
Abbreviations KHMDS
ChemSpider
  • 21171158 ☒N
ECHA InfoCard 100.115.605 Edit this at Wikidata
  • 3251421
UN number 3263
  • DTXSID00390655 Edit this at Wikidata
  • InChI=1S/C6H18NSi2.K/c1-8(2,3)7-9(4,5)6;/h1-6H3;/q-1;+1 ☒N
    Key: IUBQJLUDMLPAGT-UHFFFAOYSA-N ☒N
  • C[Si](C)(C)N([K])[Si](C)(C)C
Properties
KSi
2
C
6
NH
18
Molar mass 199.4831 g mol−1
Appearance White, opaque crystals
Reacts
Hazards
GHS labelling:
GHS05: Corrosive
Danger
H314[1]
P280, P305+P351+P338, P310[1]
Related compounds
Other cations
Lithium bis(trimethylsilyl)amide

Sodium bis(trimethylsilyl)amide

Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Infobox references

StructureEdit

In the solid state, the unsolvated compound is dimeric, with two potassium and two nitrogen atoms forming a square. This compound is soluble in hydrocarbon solvents and conducts electricity poorly in solution and in the melt. This is attributed to very strong ion pairing.[2]

See alsoEdit

ReferencesEdit

  1. ^ a b Potassium bis(trimethylsilyl)amide, Sigma-Aldrich
  2. ^ Tesh, Kris F.; Hanusa, Timothy P.; Huffman, John C. (1990). "Ion pairing in [bis(trimethylsilyl)amido]potassium: The x-ray crystal structure of unsolvated [KN(SiMe3)2]2". Inorg. Chem. 29 (8): 1584–1586. doi:10.1021/ic00333a029.