Chemistry:Benzyl potassium

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Benzyl potassium
Names
Other names
Potassium benzyl
Identifiers
3D model (JSmol)
ChemSpider
Properties
C7H7K
Molar mass 130.231 g·mol−1
Appearance Orange solid
Hazards
Main hazards Ignites in air
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references
Tracking categories (test):

Benzylpotassium is an organopotassium compound with the formula C6H5CH2K, an orange powder. Like organo-alkali metal reagents in general, benzyl potassium is highly reactive, so much so that it reacts with most solvents. It is highly air sensitive.

Synthesis

One early synthesis proceeds by two-step transmetallation reaction by p-tolylpotassium:[1]

(CH
3
C
6
H
4
)
2
Hg + 2 K → 2 CH
3
C
6
H
4
K + Hg
CH
3
C
6
H
4
K → KCH
2
C
6
H
5

A modern synthesis involves the reaction of butyllithium, potassium tert-butoxide, and toluene.[2]

The structure of the related diphenylmethane derivative has been confirmed by X-ray crystallography.[3]

References

  1. Gilman, Henry; Pacevitz, Henry A; Baine, Ogden (1940). "Benzylalkali Compounds1". Journal of the American Chemical Society 62 (6): 1514. doi:10.1021/ja01863a054. 
  2. Lochmann, L; Trekoval, J (1987). "Lithium-potassium exchange in alkyllithium/potassium t-pentoxide systems". Journal of Organometallic Chemistry 326: 1. doi:10.1016/0022-328X(87)80117-1. 
  3. Schumann, Herbert; Freckmann, Dominique M. M.; Dechert, Sebastian (2006). "Organometallic Compounds of the Lanthanides. 179. Synthesis and Structural Characterization of a Mixed Alkyl (Benzhydryl, Trimethylsilylmethyl) Lutetium Complex". Organometallics 25 (10): 2696–2699. doi:10.1021/om0601201.