Chemical Properties
Dimethylglyoxime is a white crystalline powder. Soluble in alcohol, ether, acetone and pyridine. Solubility in water 0.5g/l, insoluble in tolerate chloroform, toluene, xylene. It is one of the first selective organic reagents applied in analytical chemistry. It is an extraordinary sensitive and specific reagent for nickel. under appropriate conditions dimethylglyoxime is specific for nickel(II) and palladium(II), but it also forms coloured water-soluble complexes with iron(II), cobalt(II) and copper(II).
Uses
Dimethylglyoxime
is specific for nickel(II) ions in ammoniacal solution if alkali tartrate is
employed as masking agent to keep in solution the possibly interfering hydrolysing
salts.
Uses
Dimethylglyoxime is used as nickel-specific complexing reagent; determination of palladium.
Uses
Detection and determination of Ni and its separation from Co and many other metals. Forms a scarlet red ppt with Ni even in dil solutions. Separation of Pd from Sn, Au, Rh, and Ir, also to detect Bi with which it forms a bright yellow color and ppt.
Application
Dimethylglyoxime is a chelate ligand that can be used as an antimicrobial agent. The compound binds to metals, such as iron and copper, which are found in wastewater and industrial effluents. It can also chelate metal ions that are present in the water supply. This property makes it an effective agent for removing heavy metals from water. Dimethylglyoxime has been shown to react with various metal ions by means of Langmuir adsorption isotherms and fluorescence spectrometry. When this reaction occurs, the compound forms a complex with the metal ion. The model system is a solution of it with sodium citrate and tetramethylammonium chloride (TMA). The reaction mechanism involves protonation and deprotonation of the ligand, which occurs when the pH is changed from acidic to basic conditions.
Reactions
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
General Description
Dimethylglyoxime (DMG) is a complexing ligand. Dimethylglyoxime forms a number of mixed ligand complexes with
N-acetylglycine with metals such as VO(IV), Ni(II), Zn(II), Pd(II), Cd(II) and Pb(II). It is a useful reagent for the spectrophotometric determination of Co(II), Fe(II), Ni(II), Pd(II) and Re(VII).
Safety Profile
Poison by ingestion.
Mutation data reported. When heated to
decomposition it emits toxic fumes of NOx.
Purification Methods
Crystallise it from EtOH (10mL/g) or aqueous EtOH. [Beilstein 1 III 3105.] TOXIC.
