Dimethylglyoxime - C4H8N2O2

What is Dimethylglyoxime?

Dimethylglyoxime is a white powder with the molecular formula C₄H₈N₂O₂.

Dimethylglyoxime is soluble in methanol or in sodium hydroxide solution. It is one of the first selective organic reagents applied in analytical chemistry.

Table of Contents

• General Properties
• Dimethylglyoxime Structure
• Dimethylglyoximato Ligand
• Physical Properties
• Chemical Properties
• Uses of Dimethylglyoxime
• Frequently Asked Questions – FAQs

General Properties of Dimethylglyoxime – C₄H₈N₂O₂

Dimethylglyoxime is an extraordinarily sensitive and specific reagent for nickel. Many derivatives of Dimethylglyoxime have been synthesized and proposed. Although commonly used as a reagent specific to nickel, Dimethylglyoxime actually allows the detection of other metal ions.

Other names – 2,3-Butanedione, Biacetyl dioxime, dioxime, N-(3-hydroxyiminobutan-2-ylidene)hydroxylamine

Dimethylglyoxime Structure – C₄H₈N₂O₂

Dimethylglyoxime Structure – C4H8N2O2

Dimethylglyoximato Ligand

Dimethylglyoximato is an example of asymmetric ligand. The charge of dimethylglyoximato is -1 and so it is an anionic ligand. The number of donor atoms in dimethylglyoximato ligand is 2. It is a bidentate ligand. It coordinates through 2 N atoms.

Physical Properties of Dimethylglyoxime – C₄H₈N₂O₂

Chemical Properties of Dimethylglyoxime – C₄H₈N₂O₂

• Nickel cation reacts with dimethylglyoxime forms an insoluble red precipitate of nickel dimethylglyoxime.

Ni²⁺ + 2C₄H₈N₂O₂ → Ni(C₄H₇N₂O₂)₂↓(red precipitate) + 2H⁺

• Dimethylglyoxime reacts with ferrous sulphate and ammonium hydroxide forms a complex compound of iron and ammonium sulphate and water is formed.

FeSO₄ + 2NH₄OH + 2C₄H₈N₂O₂ → Fe(C₄H₇N₂O₂)₂ + (NH₄)₂SO₄ + 2H₂O

Uses of Dimethylglyoxime – C₄H₈N₂O₂

• Widely used in analytical chemistry as a selective precipitating reagent, detecting reagent and photometric reagent for nickel, palladium, platinum and some other metal ions.
• Used as a test for nickel release and used for jewellery and for other objects that come in direct contact with the skin. In many countries, the dimethylglyoxime test is now commercially available in pharmacies or chemist shops.
• Used as a specific precipitant for nickel and palladium. Nickel precipitates as a bright red voluminous compound from ammoniacal solution, and white palladium comes down as a yellow compound from dilute hydrochloric acid solutions. These are dried and weighed as stoichiometric compounds.