Sodium phenoxide


Sodium phenoxide 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

Most commonly, solutions of sodium phenoxide are produced by treating phenol with sodium hydroxide. Anhydrous derivatives can be prepared by combining phenol and sodium:
Like other sodium alkoxides, 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-type cluster 44.
Sodium phenoxide can be produced by the "alkaline fusion" of benzenesulfonic acid, whereby the sulfonate groups are displaced by hydroxide:
This route once was the principal industrial route to phenol.

Reactions

Sodium phenoxide is a moderately strong base. Acidification gives phenol:
Alkylation affords phenyl ethers:
The conversion is an extension of the Williamson ether synthesis. With acylating agents, one obtains esters:
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.
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Uses

Sodium Phenoxide destroys or inhibits the growth of microorganisms, so people use it to prevent odor and cleanse skin. Sodium Phenoxide prevents or slows down the growth of bacteria, so it can protect cosmetics and personal care products.