![Phenolate](https://upload.wikimedia.org/wikipedia/commons/a/a0/Phenolate.svg)
Phenolates (also called phenoxides) are
anion
An ion () is an atom or molecule with a net electrical charge.
The charge of an electron is considered to be negative by convention and this charge is equal and opposite to the charge of a proton, which is considered to be positive by convent ...
s,
salts
In chemistry, a salt is a chemical compound consisting of an ionic assembly of positively charged cations and negatively charged anions, which results in a compound with no net electric charge. A common example is table salt, with positively cha ...
, and esters of
phenols
In organic chemistry, phenols, sometimes called phenolics, are a class of chemical compounds consisting of one or more hydroxyl groups (— O H) bonded directly to an aromatic hydrocarbon group. The simplest is phenol, . Phenolic compounds are c ...
. They may be formed by reaction of phenols with strong base.
Properties
Alkali metal phenolates, such as
sodium phenolate
Sodium phenoxide (sodium phenolate) is an organic compound with the formula NaOC6H5. It is a white crystalline solid. Its anion, phenoxide, also known as phenolate, is the conjugate base of phenol. It is used as a precursor to many other organic ...
hydrolyze in aqueous solution to form basic solutions.
At pH = 10, phenol and phenolate are in approximately 1:1 proportions.
Phenolate anions are
enolate
In organic chemistry, enolates are organic anions derived from the deprotonation of carbonyl () compounds. Rarely isolated, they are widely used as reagents in the synthesis of organic compounds.
Bonding and structure
Enolate anions are electr ...
s. As such, they react as
nucleophiles
In chemistry, a nucleophile is a chemical species that forms bonds by donating an electron pair. All molecules and ions with a free pair of electrons or at least one pi bond can act as nucleophiles. Because nucleophiles donate electrons, they are ...
at both oxygen and carbon positions.
In general, reaction at oxygen occurs under
kinetic control
Thermodynamic reaction control or kinetic reaction control in a chemical reaction can decide the composition in a reaction product mixture when competing pathways lead to different products and the reaction conditions influence the selectivity or ...
, whereas reaction at carbon occurs under thermodynamic control.
Uses
Alkyl aryl ethers can be synthesized through the
Williamson ether synthesis
The Williamson ether synthesis is an organic reaction, forming an ether from an organohalide and a deprotonated alcohol ( alkoxide). This reaction was developed by Alexander Williamson in 1850. Typically it involves the reaction of an alkoxide i ...
by treating sodium phenolate with an
alkyl halide
The haloalkanes (also known as halogenoalkanes or alkyl halides) are alkanes containing one or more halogen substituents. They are a subset of the general class of halocarbons, although the distinction is not often made. Haloalkanes are widely ...
:
:C
6H
5ONa + CH
3I → C
6H
5OCH
3 + NaI
:C
6H
5ONa + (CH
3O)
2SO
2 → C
6H
5OCH
3 + (CH
3O)SO
3Na
Production of salicylic acid
Salicylic acid is produced in the
Kolbe–Schmitt reaction
The Kolbe–Schmitt reaction or Kolbe process (named after Hermann Kolbe and Rudolf Schmitt) is a carboxylation chemical reaction that proceeds by heating sodium phenoxide (the sodium salt of phenol) with carbon dioxide under pressure (100 atm, ...
between carbon dioxide and sodium phenolate.
:
See also
*
Sodium phenolate
Sodium phenoxide (sodium phenolate) is an organic compound with the formula NaOC6H5. It is a white crystalline solid. Its anion, phenoxide, also known as phenolate, is the conjugate base of phenol. It is used as a precursor to many other organic ...
References
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