Sodium methylate

Sodium methoxide

Names
IUPAC name Sodium methoxide
Other names Sodium methylate
Identifiers
CAS Number	124-41-4 Y
3D model (JSmol)	Interactive image
ChemSpider	29033 Y
ECHA InfoCard	100.004.273
PubChem CID	10942334
UNII	IG663U5EMC Y
InChI InChI=1S/CH3O.Na/c1-2;/h1H3;/q-1;+1 Y Key: WQDUMFSSJAZKTM-UHFFFAOYSA-N Y InChI=1/CH3O.Na/c1-2;/h1H3;/q-1;+1 Key: WQDUMFSSJAZKTM-UHFFFAOYAC
SMILES [Na+].[O-]C
Properties
Chemical formula	CH3NaO
Molar mass	54.02 g/mol
Appearance	White solid
Melting point	127 °C (261 °F; 400 K)
Boiling point	> 300 °C (572 °F; 573 K)
Solubility	Soluble in ethanol, methanol Insoluble in hydrocarbons
Structure
Crystal structure	Hexagonal
Hazards
EU classification (DSD) (outdated)	Harmful (Xn), Corrosive (C)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Y  (what is YN ?)
Infobox references

Sodium methoxide is a chemical compound with the formula CH₃ONa. This colorless solid, which is formed by the deprotonation of methanol, is a widely used reagent in industry and the laboratory. It is also a dangerously caustic base.

Sodium methoxide is prepared by carefully treating methanol with sodium:

The reaction is so exothermic that ignition is possible. The resulting solution, which is colorless, is often used as a source of sodium methoxide, but the pure material can be isolated by evaporation followed by heating to remove residual methanol. The solid hydrolyzes in water to give methanol and sodium hydroxide; commercial-grade product can be contaminated with the hydroxide. The solid and especially solutions absorb carbon dioxide from the air, thus diminishing the effectiveness of the base.

In the solid form, sodium methoxide is polymeric, with sheet-like arrays of Na⁺ centers, each bonded to four oxygen centers.

The structure, and hence the basicity, of sodium methoxide in solution depends on the solvent. It is a significantly stronger base in DMSO where it is more fully ionized and free of hydrogen bonding.

Sodium methoxide is a routinely used base in organic chemistry, applicable to the synthesis of numerous compounds ranging from pharmaceuticals to agrichemicals. As a base, it is employed in dehydrohalogenations and various condensations. It is also a nucleophile for the production of methyl ethers.

Sodium methoxide is used as an initiator of anionic addition polymerization with ethylene oxide, forming a polyether with high molecular weight. Biodiesel is prepared from vegetable oils and animal fats, that is, fatty acid triglycerides, by transesterification with methanol to give fatty acid methyl esters (FAMEs). This transformation is catalyzed by sodium methoxide.