Chemistry:Tetramethylphosphonium bromide

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Short description: A white, water-soluble organophosphorus compound
Tetramethylphosphonium bromide
Me4PBr.png
Identifiers
3D model (JSmol)
ChemSpider
UNII
Properties
C4H12BrP
Molar mass 171.018 g·mol−1
Appearance white solid
Hazards
GHS pictograms GHS07: Harmful
GHS Signal word Warning
H315, H319, H335
P261, P264, P271, P280, P302+352, P304+340, P305+351+338, P312, P321, P332+313, P337+313, P362, P403+233, P405, P501
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references

Tetramethylphosphonium bromide is an organophosphorus compound with the formula (CH3)4PBr. It is a white, water-soluble solid, the salt of the cation tetramethylphosphonium and the bromide anion. It is prepared by treating trimethylphosphine with methyl bromide.

Reactions

Structure of Cu2[(Me2P(CH2)2]2.

Deprotonation gives methylenetrimethylphosphine ylide, which can sustain a second deprotonation:[1]

(CH3)4PBr + BuLi → CH3)3P=CH2 + LiBr + BuH
CH3)3P=CH2 + BuLi → CH3)2P(CH2)2Li + BuH

The latter is a precursor to many coordination complexes, e.g., the dicuprous complex Cu2[(Me2P(CH2)2]2.[2]

References

  1. H. F. Klein (1978). "Trimethylphosphonium Methylide (Trimethyl Methylenephosphorane)". Inorganic Syntheses XVIII: 138-140. doi:10.1002/9780470132494.ch23. 
  2. Schmidbaur, H. (1983). "Phosphorus Ylides in the Coordination Sphere of Transition Metals: An Inventory". Angewandte Chemie International Edition in English 22 (12): 907–927. doi:10.1002/anie.198309071.