Dimethylglyoxime

Dimethylglyoxime (dmg) is a chemical compound used in the field of analytical chemistry to detect the presence of nickel. It forms a bright red complex with nickel in a 2:1 ratio. Dimethylglyoxime is a white, crystalline solid at room temperature and is slightly soluble in water. It is often used in its salt forms, such as the sodium or potassium salts, which are more soluble in water than the parent compound.

Structure and properties

Dimethylglyoxime is a dioxime, which refers to the two oxime functional groups found in its structure. The molecule is planar and adopts a trans configuration. The two oxime groups are anti to each other, and the molecule has a center of symmetry. The molecular formula of dimethylglyoxime is C4H8N2O2.

Preparation

Dimethylglyoxime can be prepared from methyl ethyl ketone and hydroxylamine. The reaction involves the condensation of two molecules of methyl ethyl ketone with hydroxylamine, followed by oxidation to give the dioxime.

Uses

The primary use of dimethylglyoxime is in the gravimetric analysis of nickel. The red complex that forms is insoluble in water and can be filtered, washed, and weighed to determine the amount of nickel present in a sample.

Safety

Dimethylglyoxime is not considered highly toxic, but it can cause irritation to the skin and eyes. It should be handled with care and appropriate safety precautions should be taken when using it in the laboratory.

See also

• Gravimetric analysis
• Nickel
• Oxime