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Phenylmagnesium bromide

Phenylmagnesium bromide
Phenylmagnesium bromide, OR2 = ether or THF
Complex with ethers
Ball-and-stick model of the PhMgBr-diethyl ether adduct
Complex with diethyl ether
Space-filling model of the PhMgBr-diethyl ether adduct
Names
IUPAC name
Bromido(phenyl)magnesium
Other names
PMB, (bromomagnesio)benzene
Identifiers
3D model (Jmol)
ChemSpider
ECHA InfoCard 100.002.607
PubChem CID
Properties
C6H5MgBr
Molar mass 181.31 g mol−1
Appearance Colorless crystals
Density 1.14 g cm−3
Reacts with water
Solubility Soluble in diethyl ether and THF
Basicity (pKb) Strong base
Hazards
Main hazards flammable, volatile
Safety data sheet External MSDS
R-phrases R12 R14/15 R20/22 R35 R41
S-phrases S16 S26 S30 S33 S36/37/39 S43 S45 S60 S61
Flash point −45 °C (−49 °F; 228 K)
Related compounds
Related compounds
Phenyllithium
Magnesium bromide
Methylmagnesium chloride
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
N  (what is YesYN ?)
Infobox references

Phenylmagnesium bromide, with the simplified formula C
6
H
5
MgBr
, is a magnesium-containing organometallic compound. It is commercially available as a solution in diethyl ether or tetrahydrofuran (THF). Phenylmagnesium bromide is a Grignard reagent. It is often used as a synthetic equivalent for the phenyl "Ph" synthon.

Phenylmagnesium bromide is commercially available as solutions of diethyl ether or THF. Laboratory preparation involves treating bromobenzene with magnesium metal, usually in the form of turnings. A small amount of iodine may be used to activate the magnesium to initiate the reaction.

Coordinating solvents such as ether or THF, are required to solvate (complex) the magnesium(II) center. The solvent must be aprotic since alcohols and water contain an acidic proton and thus react with phenylmagnesium bromide to give benzene. Carbonyl-containing solvents, such as acetone and ethyl acetate, are also incompatible with the reagent.

Although phenylmagnesium bromide is routinely represented as C
6
H
5
MgBr
, the molecule is more complex. The compound invariably forms an adduct with two OR
2
ligands from the ether or THF solvent. Thus, the Mg is tetrahedral and obeys the octet rule. The Mg–O distances are 201 and 206 pm whereas the Mg–C and Mg–Br distances are 220 pm and 244 pm, respectively.


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