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{{Short description|Chemical Compound}}
{{Chembox
{{Chembox
| ImageFile = Fenolan sodu.svg
| ImageFile = Structural formula of sodium phenoxide.svg
| ImageSize = 75px
| ImageSize = 130px
| ImageAlt =
| ImageAlt =
| ImageFile1 = File:Sodium-phenoxide-3D-balls.png
| IUPACName =
| ImageAlt1 =
| PIN = Sodium phenoxide<ref>{{cite book |author=[[International Union of Pure and Applied Chemistry]] |date=2014 |title=Nomenclature of Organic Chemistry: IUPAC Recommendations and Preferred Names 2013 |publisher=[[Royal Society of Chemistry|The Royal Society of Chemistry]] |pages=1071, 1129 |doi=10.1039/9781849733069 |isbn=978-0-85404-182-4}}</ref>
| OtherNames = Sodium phenolate
| OtherNames = Sodium phenolate
|Section1={{Chembox Identifiers
|Section1={{Chembox Identifiers
| CASNo = 139-02-6
| CASNo = 139-02-6
| CASNo_Ref = {{cascite|correct|CAS}}
| UNII = 4NC0T56V35
| UNII_Ref = {{fdacite|correct|FDA}}
| PubChem = 4445035
| PubChem = 4445035
| ChemSpiderID = 8420
| ChemSpiderID = 8420
| SMILES = c1ccc(cc1)[O-].[Na+]
| SMILES = [Na+].[O-]c1ccccc1
| InChI = 1/C6H6O.Na/c7-6-4-2-1-3-5-6;/h1-5,7H;/q;+1/p-1
| InChI = 1/C6H6O.Na/c7-6-4-2-1-3-5-6;/h1-5,7H;/q;+1/p-1
| InChIKey = NESLWCLHZZISNB-REWHXWOFAP
| InChIKey = NESLWCLHZZISNB-REWHXWOFAP
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| Solubility = }}
| Solubility = }}
|Section3={{Chembox Hazards
|Section3={{Chembox Hazards
| MainHazards =
| MainHazards = Harmful, Corrosive
| FlashPt =
| FlashPt = Non-flammable
| AutoignitionPt = }}
| AutoignitionPt = Non-flammable }}
}}
}}


'''Sodium phenoxide''' is an [[organic compound]] with the formula NaOC<sub>6</sub>H<sub>5</sub>. This white solid is the [[conjugate base]] of [[phenol]]. It is used as a precursor to many other organic compounds, such as aryl [[ether]]s.
'''Sodium phenoxide''' ('''sodium phenolate''') is an [[organic compound]] with the formula NaOC<sub>6</sub>H<sub>5</sub>. 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 compounds, such as aryl [[ether]]s.


==Synthesis and structure==
==Synthesis and structure==
Most commonly, solutions of sodium phenoxide are produced by treating phenol with sodium hydroxide.<ref name=Speed>C. S. Marvel and A. L. Tanenbaum "γ-Phenoxypropyl Bromide" Org. Synth. 1929, vol. 9, pp. 72.</ref> Anhydrous derivatives can be prepared from phenol and sodium:
Most commonly, solutions of sodium phenoxide are produced by treating phenol with sodium hydroxide.<ref name=Speed>{{cite journal|author=C. S. Marvel |author2=A. L. Tanenbaum |title=γ-Phenoxypropyl Bromide|journal=Org. Synth.|year=1929|volume= 9|page=72|doi=10.15227/orgsyn.009.0072}}</ref> Anhydrous derivatives can be prepared by combining phenol and sodium. A related, updated procedure uses sodium methoxide instead of sodium hydroxide:<ref>{{cite journal |doi=10.1021/ja01520a030|title=Heterogeneity as a Factor in the Alkylation of Ambident Anions: Phenoxide Ions1,2|year=1959|last1=Kornblum|first1=Nathan|last2=Lurie|first2=Arnold P.|journal=Journal of the American Chemical Society|volume=81|issue=11|pages=2705–2715}}</ref>
:Na + HOC<sub>6</sub>H<sub>5</sub> → NaOC<sub>6</sub>H<sub>5</sub> + 1/2 H<sub>2</sub>
:NaOCH<sub>3</sub> + HOC<sub>6</sub>H<sub>5</sub> → NaOC<sub>6</sub>H<sub>5</sub> + HOCH<sub>3</sub>
⚫
Sodium phenoxide can also be produced by the "alkaline fusion" of [[benzenesulfonic acid]], whereby the sulfonate groups are displaced by hydroxide:
⚫
:C<sub>6</sub>H<sub>5</sub>SO<sub>3</sub>Na + 2 NaOH → C<sub>6</sub>H<sub>5</sub>OH + Na<sub>2</sub>SO<sub>3</sub>
⚫
This route once was the principal industrial route to phenol.{{Citation needed|date=September 2022}}
==Structure==
⚫
Like other sodium [[alkoxide]]s, solid sodium phenoxide adopts a complex structure involving multiple Na-O bonds. Solvent-free material is polymeric, each Na center being bound to three oxygen ligands [[hapticity|as well as the phenyl ring]]. Adducts of sodium phenoxide are molecular, such as the [[cubane-type cluster]] [NaOPh]<sub>4</sub>([[HMPA]])<sub>4</sub>.<ref>Michael Kunert, Eckhard Dinjus, Maria Nauck, Joachim Sieler "Structure and Reactivity of Sodium Phenoxide - Following the Course of the Kolbe-Schmitt Reaction" Chemische Berichte 1997 Volume 130, Issue 10, pages 1461–1465. {{doi|10.1002/cber.19971301017}}</ref>


{|style="margin: 0 auto;"
⚫
Like other sodium [[alkoxide]]s, crystalline sodium phenolate adopts a complex structure involving multiple Na-O bonds. Solvent-free material is polymeric, each Na center being bound to three oxygen ligands as well as the [[phenyl ring]]. Adducts of sodium phenoxide are molecular, such as the cubane [NaOPh]<sub>4</sub>([[HMPA]])<sub>4</sub>.<ref>Michael Kunert, Eckhard Dinjus, Maria Nauck, Joachim Sieler "Structure and Reactivity of Sodium Phenoxide - Following the Course of the Kolbe-Schmitt Reaction" Chemische Berichte 1997 Volume 130, Issue 10, pages 1461–1465. {{DOI|10.1002/cber.19971301017}}</ref>
| [[File:Sodium-phenoxide-xtal-3D-SF-B.png|300px|thumb|Part of the crystal structure of pure sodium phenoxide]]

| [[File:Sodium-phenoxide-Na-coordination-3D-balls.png|300px|thumb|Subunit of the crystal structure of pure sodium phenoxide, illustrating the binding of phenoxide ions to sodium through both the oxygen and the arene.]]
⚫
Sodium phenoxide is produced by the "alkaline fusion" of [[benzenesulfonic acid]], whereby the sulfonate groups is displaced by hydroxide:
|}
⚫
:C<sub>6</sub>H<sub>5</sub>SO<sub>3</sub>Na + 2 NaOH → C<sub>6</sub>H<sub>5</sub>ONa + Na<sub>2</sub>SO<sub>3</sub>
⚫
This route once was the principal industrial route to phenol.

[[File:Sodium-phenoxide-Na-coordination-3D-balls.png|200px|Ball-and-stick model of the sodium coordination geometry in unsolvated sodium phenoxide]] [[File:Sodium-phenoxide-column-3D-SF.png|200px|Space-filling model of part of a chain in the crystal structure of unsolvated sodium phenoxide]]


==Reactions==
==Reactions==
Sodium phenoxide is a moderately strong base. At low pH's gives phenol:<ref>{{March6th}}</ref>
Sodium phenoxide is a moderately strong base. Acidification gives phenol:<ref>{{March6th}}</ref>
:PhOH &#x21CC; PhO<sup>−</sup> + H<sup>+</sup>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(K = 10<sup>−10</sup>)
:PhOH ⇌ PhO<sup>−</sup> + H<sup>+</sup>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(K = 10<sup>−10</sup>)
The acid-base behavior is complicated by [[homoassociation]], reflecting the association of phenol and phenoxide.<ref>{{cite book|title=Acid-Base Dissociation Constants in Dipolar Aprotic Solvents|author=K. Izutsu |publisher=Blackwell Scientific Publications|year=1990|volume=35}}</ref>


Sodium phenoxide can be used to prepare phenyl ethers and metal phenolates:<ref name=Speed/>
Sodium phenoxide reacts with alkylating agents to afford alkyl phenyl ethers:<ref name=Speed/>
:NaOC<sub>6</sub>H<sub>5</sub> + RBr → ROC<sub>6</sub>H<sub>5</sub> + NaBr
:NaOC<sub>6</sub>H<sub>5</sub> + RBr → ROC<sub>6</sub>H<sub>5</sub> + NaBr
The conversion is an extension of the [[Williamson ether synthesis]]. With acylating agents, one obtains phenyl esters:{{citation needed|date=May 2024}}
:NaOC<sub>6</sub>H<sub>5</sub> + RC(O)Cl → RCO<sub>2</sub>C<sub>6</sub>H<sub>5</sub> + NaCl

Sodium phenoxide is susceptible to certain types of [[electrophilic aromatic substitution]]s. For example, it reacts with carbon dioxide to form 2-hydroxybenzoate, the conjugate base of [[salicylic acid]]. In general however, electrophiles irreversibly attack the oxygen center in phenoxide.{{citation needed|date=May 2024}}
:[[image:Kolbe-Schmitt.png|500px|left|The [[Kolbe–Schmitt reaction]].]]{{clear-left}}


==References==
==References==
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{{commons category inline}}
{{commons category inline}}


[[Category:Phenols]]
[[Category:Phenolates]]
[[Category:Organic sodium salts]]
[[Category:Organic sodium salts]]

Latest revision as of 05:06, 8 July 2024

Sodium phenoxide
Names
Preferred IUPAC name
Sodium phenoxide[1]
Other names
Sodium phenolate
Identifiers
3D model (JSmol)
ChemSpider
ECHA InfoCard 100.004.862 Edit this at Wikidata
UNII
  • InChI=1S/C6H6O.Na/c7-6-4-2-1-3-5-6;/h1-5,7H;/q;+1/p-1
    Key: NESLWCLHZZISNB-UHFFFAOYSA-M
  • InChI=1/C6H6O.Na/c7-6-4-2-1-3-5-6;/h1-5,7H;/q;+1/p-1
    Key: NESLWCLHZZISNB-REWHXWOFAP
  • [Na+].[O-]c1ccccc1
Properties
C6H5NaO
Molar mass 116.09 g/mol
Appearance White solid
Hazards
Occupational safety and health (OHS/OSH):
Main hazards
 Harmful, Corrosive
Flash point Non-flammable
Non-flammable
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

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 compounds, such as aryl ethers.

Synthesis and structure

[edit]

Most commonly, solutions of sodium phenoxide are produced by treating phenol with sodium hydroxide.[2] Anhydrous derivatives can be prepared by combining phenol and sodium. A related, updated procedure uses sodium methoxide instead of sodium hydroxide:[3]

NaOCH3 + HOC6H5 → NaOC6H5 + HOCH3

Sodium phenoxide can also be produced by the "alkaline fusion" of benzenesulfonic acid, whereby the sulfonate groups are displaced by hydroxide:

C6H5SO3Na + 2 NaOH → C6H5OH + Na2SO3

This route once was the principal industrial route to phenol.[citation needed]

Structure

[edit]

Like other sodium alkoxides, solid sodium phenoxide adopts a complex structure involving multiple Na-O bonds. Solvent-free material is polymeric, each Na center being bound to three oxygen ligands as well as the phenyl ring. Adducts of sodium phenoxide are molecular, such as the cubane-type cluster [NaOPh]4(HMPA)4.[4]

Part of the crystal structure of pure sodium phenoxide
Subunit of the crystal structure of pure sodium phenoxide, illustrating the binding of phenoxide ions to sodium through both the oxygen and the arene.

Reactions

[edit]

Sodium phenoxide is a moderately strong base. Acidification gives phenol:[5]

PhOH ⇌ PhO− + H+          (K = 10−10)

The acid-base behavior is complicated by homoassociation, reflecting the association of phenol and phenoxide.[6]

Sodium phenoxide reacts with alkylating agents to afford alkyl phenyl ethers:[2]

NaOC6H5 + RBr → ROC6H5 + NaBr

The conversion is an extension of the Williamson ether synthesis. With acylating agents, one obtains phenyl esters:[citation needed]

NaOC6H5 + RC(O)Cl → RCO2C6H5 + NaCl

Sodium phenoxide is susceptible to certain types of electrophilic aromatic substitutions. For example, it reacts with carbon dioxide to form 2-hydroxybenzoate, the conjugate base of salicylic acid. In general however, electrophiles irreversibly attack the oxygen center in phenoxide.[citation needed]

The Kolbe–Schmitt reaction.
The Kolbe–Schmitt reaction.

References

[edit]
  1. ^ International Union of Pure and Applied Chemistry (2014). Nomenclature of Organic Chemistry: IUPAC Recommendations and Preferred Names 2013. The Royal Society of Chemistry. pp. 1071, 1129. doi:10.1039/9781849733069. ISBN 978-0-85404-182-4.
  2. ^ a b C. S. Marvel; A. L. Tanenbaum (1929). "γ-Phenoxypropyl Bromide". Org. Synth. 9: 72. doi:10.15227/orgsyn.009.0072.
  3. ^ Kornblum, Nathan; Lurie, Arnold P. (1959). "Heterogeneity as a Factor in the Alkylation of Ambident Anions: Phenoxide Ions1,2". Journal of the American Chemical Society. 81 (11): 2705–2715. doi:10.1021/ja01520a030.
  4. ^ Michael Kunert, Eckhard Dinjus, Maria Nauck, Joachim Sieler "Structure and Reactivity of Sodium Phenoxide - Following the Course of the Kolbe-Schmitt Reaction" Chemische Berichte 1997 Volume 130, Issue 10, pages 1461–1465. doi:10.1002/cber.19971301017
  5. ^ Smith, Michael B.; March, Jerry (2007), Advanced Organic Chemistry: Reactions, Mechanisms, and Structure (6th ed.), New York: Wiley-Interscience, ISBN 978-0-471-72091-1
  6. ^ K. Izutsu (1990). Acid-Base Dissociation Constants in Dipolar Aprotic Solvents. Vol. 35. Blackwell Scientific Publications.
[edit]

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