Dimethylglyoxime

Dimethylglyoxime is a chemical compound described by the formula CH₃C(NOH)C(NOH)CH₃. 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 (also known as diacetyl). 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.

Dimethylglyoxime

Dimethylglyoxime
Names
IUPAC name N,N′-Dihydroxy-2,3-butanediimine
Other names Dimethylglyoxime Diacetyl dioxime Butane-2,3-dioxime Chugaev's reagent
Identifiers
CAS Number	95-45-4 Y 17117-97-4 (E) Y
3D model (JSmol)	Interactive image
ChEMBL	ChEMBL3184098
ChemSpider	10606175 Y
ECHA InfoCard	100.002.201
EC Number	202-420-1
PubChem CID	135399895
RTECS number	EK2975000
UNII	2971MFT1KY Y
CompTox Dashboard (EPA)	DTXSID2044393
InChI InChI=1S/C4H8N2O2/c1-3(5-7)4(2)6-8/h7-8H,1-2H3/b5-3-,6-4+ Y Key: JGUQDUKBUKFFRO-CIIODKQPSA-N Y InChI=1/C4H8N2O2/c1-3(5-7)4(2)6-8/h7-8H,1-2H3/b5-3-,6-4+ Key: JGUQDUKBUKFFRO-CIIODKQPBA
SMILES C\C(=N\O)\C(\C)=N\O
Properties
Chemical formula	C4H8N2O2
Molar mass	116.120 g·mol−1
Appearance	White/Off White Powder
Density	1.37 g/cm3
Melting point	240 to 241 °C (464 to 466 °F; 513 to 514 K)
Boiling point	decomposes
Solubility in water	low
Structure
Dipole moment	0
Hazards
Occupational safety and health (OHS/OSH):
Main hazards	Toxic, Skin/Eye Irritant
GHS labelling:
Pictograms
Signal word	Danger
Hazard statements	H228, H301
Precautionary statements	P210, P240, P241, P264, P270, P280, P301+P310, P321, P330, P370+P378, P405, P501
NFPA 704 (fire diamond)	2
Safety data sheet (SDS)	External MSDS
Related compounds
Related compounds	Hydroxylamine salicylaldoxime
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Y verify (what is YN ?) Infobox references

Preparation and reactions

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:^[1]

2,3-Butanediamine is produced by reduction of dimethylglyoxime with lithium aluminium hydride.^[2]

Complexes

Dimethylglyoxime forms complexes with metals including nickel,^[3] palladium and cobalt.^[4] These complexes are used to separate those cations from solutions of metal salts and in gravimetric analysis. It is also used in precious metals refining to precipitate palladium from solutions of palladium chloride.

Dimethylglyoxime Complexes

• 
  Reaction of Ni-dmg-Formation
• 
  Sample of Ni(dmgH)₂
• 
  Structure of chloro(pyridine)cobaloxime