Tetramethylphosphonium bromide is an
organophosphorus compound
Organophosphorus compounds are organic compounds containing phosphorus. They are used primarily in pest control as an alternative to chlorinated hydrocarbons that persist in the environment. Some organophosphorus compounds are highly effective in ...
with the formula (CH
3)
4PBr. It is a white, water-soluble solid, the salt of the cation tetramethyl
phosphonium
In polyatomic cations with the chemical formula (where R is a hydrogen or an alkyl, aryl, or halide group). These cations have tetrahedral structures. The salts are generally colorless or take the color of the anions.
Types of phosphonium ...
and the
bromide
A bromide ion is the negatively charged form (Br−) of the element bromine, a member of the halogens group on the periodic table. Most bromides are colorless. Bromides have many practical roles, being found in anticonvulsants, flame-retardant ...
anion. It is prepared by treating
trimethylphosphine
Trimethylphosphine is a neutral organophosphorus compound with the formula P(CH3)3, commonly abbreviated as PMe3. This colorless liquid has a strongly unpleasant odor, characteristic of alkylphosphines. The compound is a common ligand in coordin ...
with
methyl bromide
Bromomethane, commonly known as methyl bromide, is an organobromine compound with formula C H3 Br. This colorless, odorless, nonflammable gas is produced both industrially and biologically. It has a tetrahedral shape and it is a recognized ozon ...
.
Reactions
Deprotonation gives methylenetrimethylphosphine ylide, which can sustain a second deprotonation:
:(CH
3)
4PBr + BuLi → CH
3)
3P=CH
2 + LiBr + BuH
:CH
3)
3P=CH
2 + BuLi → CH
3)
2P(CH
2)
2Li + BuH
The latter is a precursor to many coordination complexes, e.g., the dicuprous complex Cu
2 2P(CH2)2">Me2P(CH2)2sub>2.
[{{cite journal, author=Schmidbaur, H., title=Phosphorus Ylides in the Coordination Sphere of Transition Metals: An Inventory, journal=Angewandte Chemie International Edition in English, year=1983, volume=22, issue=12, pages=907–927, doi=10.1002/anie.198309071]
References
Quaternary phosphonium compounds
Bromides