orange to brown crystalline powder
As a reagent for copper, cobalt, and nickel. As a stabilizer of ascorbic acid solutions: Smoczkiewicz, Grochmalicka, Nature 192, 16 (1961).
Rubeanic acid may be used for the quantitative precipitation of copper, nickel
and cobalt. The copper complex is dark green, the cobalt brownish-red and the
nickel violet. All these complexes are chelates of outstanding stability, and this,
together with their vivid Colours, affords the reaction great analytical sensitivity.
The copper complex is the most stable of the three; it can be precipitated even
from mild mineral acidic solution, while precipitation of the corresponding cobalt
and nickel complexes requires buffered media. On the other hand, palladium,
platinum and silver react with rubeanic acid to give precipitates in strongly acidic
solution. It should be mentioned, however, that in the case of platinum and
some other metals (zinc, cadmium, silver, lead, mercury) the product is the corresponding
sulfide rather than the rubeanate complex.
Rubeanic acid reacts with ruthenium to give a blue water-soluble complex ion,
which is utilized for the spectrophotometric determination of ruthenium.
Rubeanic acid has similarly been used for the spectrophotometric determination
of osmium.
It has also proved suitable for the solvent extraction separation and determination
of thallium. It has been found that thallium exists in the organic phase
in the form of a complex of composition Tl/dto/Hdto, where dto represents the
rubeanate anion with one negative charge.
Dithiooxamide acts as a chelating agent and used in the determination of copper(II), nickel(II) and cobalt(II). It is used as a building block in the synthesis of cyclen. It is involved in the preparation of thiazolothiazole-linked porous organic polymers and N,N'-disubstituted dithiooxamides. It is also employed as a modifier to prepare the modified glassy carbon electrode which is used to investigate the electrochemical properties of quercetin, an important flavonoid derivative. Further, it is involved in the preparation of chelating resin with formaldehyde, which finds application in separation and concentration of silver ions.
Dithiooxamide is reported to form complexes with Ni(II).
Poison by ingestion,
intraperitoneal, and intravenous routes.
When heated to decomposition it emits very
toxic fumes of NOx and SOx
Crystallise dithiooxamide from EtOH and sublime it at high vacuum. [Beilstein 2 IV 1871.]
