Alkoxide

Alcoholates, also called alkoxides, are salts of metal cations and alkoxide. The general formula is (RO ) n M (M = metal ion, n is the valency of this metal ion ). Alcoholate resulting from deprotonation of alcohols. In an aqueous medium not alcoholates can be prepared because the hydroxide is too weakly basic to deprotonate the hydroxy group of alcohols. Therefore, stronger bases such as sodium amide or elemental sodium, are used. Alkoxides are used, among other things, to ether synthesis as well as condensation, deprotonation and alkylating agents.

Representation

Alkoxides may be synthesized by the reaction of elemental alkali metals with alcohols.

Example is the formation of sodium ethoxide ( sodium, C2H5ONa ) as a white to yellowish, hygroscopic powder by the action of sodium on ethanol to hydrogen gas escapes:

Properties

In its pure form alcoholates are strongly basic solids, however, draw water from the air and steam to melt away gradually, the corresponding alcohol and the metal hydroxide arise, for example, by:

Use of and reactions

Technically alcoholates find application in the asymmetric ether synthesis ( Williamson ether synthesis with haloalkanes ) (1 ) or strong bases. With carbonyl halides are esters can be represented (2); with primary amines, secondary amines are obtained (3). On contact with water alkoxides react in an acid -base reaction to the corresponding alcohol and hydroxide ions. (4)

Alkoxides are mainly used by the agricultural and pharmaceutical industries. And in the production of biodiesel and cosmetics alkoxides may be used.

Furthermore alcoholates are increasingly used in sol-gel processes for the production of thin films, nanoparticles and highly porous materials. In this way can be functional (e.g., by ultraviolet light -activated self - disinfecting layers ), optical (such as anti-reflective layers, porous silica ), as well as electronically active ( semiconductor ) layers (e.g., indium tin oxide, zinc oxide and titanium dioxide ) are generated.