Dimethylglyoxime


Dimethylglyoxime is a chemical compound described by the formula CH3CCCH3. Its abbreviation is dmgH2 for neutral form, and dmgH for anionic form, where H stands for hydrogen. This colourless solid is the dioxime derivative of the diketone butane-2,3-dione. DmgH2 is used in the analysis of palladium or nickel. Its coordination complexes are of theoretical interest as models for enzymes and as catalysts. Many related ligands can be prepared from other diketones, e.g. benzil.

Preparation

Dimethylglyoxime can be prepared from butanone first by reaction with ethyl nitrite to give biacetyl monoxime. The second oxime is installed using sodium hydroxylamine monosulfonate:

Complexes

Dimethylglyoxime forms complexes with metals including Nickel, Palladium, and Cobalt. These complexes are used to separate those complexes from solutions of metal salts. It is also used in precious metals refining to precipitate palladium from solutions of palladium chloride.