Sodium methoxide


Sodium methoxide
Sodium methoxide
Identifiers
CAS number 124-41-4 YesY
PubChem 10942334
ChemSpider 29033 YesY
UNII IG663U5EMC YesY
Jmol-3D images Image 1
Properties
Molecular formula CH3NaO
Molar mass 54.02
Appearance white solid
Melting point

>300 °C

Hazards
MSDS Oxford MSDS
EU classification Harmful (Xn), Corrosive (C)
 YesY methoxide (verify) (what is: YesY/N?)
Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

Sodium methoxide is a chemical compound, with formula CH3ONa. This colourless 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.

Contents

Preparation and structure

Sodium methoxide is prepared by carefully treating methanol with sodium :

2 Na + 2 CH3OH → 2 CH3ONa + H2

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 sodium hydroxide, and commercial samples are significantly 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 a sheet-like arrays of Na+ centers, each bonded to four oxygen centers.[1]

The structure, and hence its basicity, of sodium methoxide in solution depends on the solvent. It is significantly stronger base in DMSO where it is more fully ionized and free of hydrogen bonding.[2]

Applications

Organic synthesis

Sodium methoxide is a routine base in organic chemistry, applicable to the synthesis of numerous compounds, ranging from pharmaceuticals to agrichemicals.[2] As a base, it is employed in dehydrohalogenations and aldol condensations. It is also a nucleophile for the production of methyl ethers. [3]

Industrial applications

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.

Safety

Sodium methoxide is highly caustic, and the hydrolysis gives methanol, which is toxic and volatile.

References

  1. ^ E. Weiss, “Die Kristallstruktur des Natriummethylats” Zeitschrift fur Anorganische und Allgemeine Chemie 1964, volume 332, p. 197-203. doi:10.1002/zaac.19643320311
  2. ^ a b Y. El-Kattan, J. McAtee, B. Bessieres “Sodium Methoxide” in Encyclopedia of Reagents for Organic Synthesis, John Wiley & Sons, 2006, New York. doi:10.1002/047084289X.rs089m.pub2. Article Online Posting Date: September 15, 2006.
  3. ^ Frederic Reverdin, "3,5-Dinitroanisolel", Org. Synth., http://www.orgsyn.org/orgsyn/orgsyn/prepContent.asp?prep=cv1p0219 ; Coll. Vol. 1: 219 

See also


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Look at other dictionaries:

  • sodium methoxide — natrio metilatas statusas T sritis chemija formulė CH₃ONa atitikmenys: angl. sodium methylate; sodium methoxide rus. метилат натрия; метоксид натрия ryšiai: sinonimas – natrio metoksidas …   Chemijos terminų aiškinamasis žodynas

  • Sodium hydrosulfide — IUPAC name Sodium hydrosulfide …   Wikipedia

  • Methoxide — Methoxides are organic salts and the simplest alkoxides. Sodium methoxide and potassium hydroxide have widespread use, though other variants such as lithium hydroxide, rubidium methoxide, caesium methoxide, and francium methoxide exist as well.… …   Wikipedia

  • sodium — /soh dee euhm/, n. 1. Chem. a soft, silver white, metallic element that oxidizes rapidly in moist air, occurring in nature only in the combined state, and used in the synthesis of sodium peroxide, sodium cyanide, and tetraethyllead: a necessary… …   Universalium

  • sodium borohydride — noun : a hygroscopic crystalline compound NaBH4 that is flammable but remarkably stable in air and decomposes readily in water only above room temperature or in the presence of acid to yield hydrogen and sodium metaborate, that is made in various …   Useful english dictionary

  • methoxide — (ˈ)meth+ noun Etymology: meth + oxide : a binary compound of methoxyl; especially : a base formed from methanol by replacement of the hydroxyl hydrogen with a metal sodium methoxide NaOCH3 * * * /meth ok suyd, sid/, n. Chem. methylate (def. 1).… …   Useful english dictionary

  • sodium methylate — Chem. a white, free flowing, flammable powder, CH3ONa, decomposed by water to sodium hydroxide and methyl alcohol: used chiefly in organic synthesis. Also called sodium methoxide. * * * …   Universalium

  • sodium methylate — natrio metilatas statusas T sritis chemija formulė CH₃ONa atitikmenys: angl. sodium methylate; sodium methoxide rus. метилат натрия; метоксид натрия ryšiai: sinonimas – natrio metoksidas …   Chemijos terminų aiškinamasis žodynas

  • sodium methylate — Chem. a white, free flowing, flammable powder, CH3ONa, decomposed by water to sodium hydroxide and methyl alcohol: used chiefly in organic synthesis. Also called sodium methoxide …   Useful english dictionary

  • Méthanolate de sodium — Général Nom IUPAC méthanolate de sodium Synonymes m …   Wikipédia en Français


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