Potassium hexanitrocobaltate

Addition of potassium nitrite, KNO2 to a solution of cobalt(lI) chloride yields yellow crystalline potassium hexanitrocobaltate(lIl), K3Co(N02)e. 

Potassium Hexanitrocobaltate(III). Add a little acetic acid and an excess of potassium nitrite to a cobalt(II) salt solution. Heat the mixture. What gas evolves What precipitates Write the equation of the reaction. What is the coordination number of cobalt in this compound ... 

III) nitrate cis-[Co en2(N02)2]NC>3, N 29.44%. Brown-yell cryst, may be prepd by treating potassium hexanitrocobaltate (III) with dil aq soln of ethylenediamine (abbr en), C2H4(NH2)2, followed by heating and cooling. The resulting nitrite cis-[Co en2(N02)2]N02 was oxidized to nitrate by treatment with coned HNO3... 

Sodium hexanitrocobaltate (III) (Na3[Co(N02)6]) Tartaric acid solution (sodium acetate buffered) Yellow precipitate of potassium hexanitrocobaltate (III) insoluble in acetic acid White precipitate of potassium hydrogen tartrate... 

Werner1,3 prepared as-dinitrobis(ethylenediamine)co-balt(III) nitrate by heating ethylenediamine with potassium hexanitrocobaltate(III) to give the dinitrobis(ethylenedia-mine)cobalt(III) nitrite, followed by conversion to the nitrate with nitric acid. The procedure given here for the cis compound utilizes this method. 

The method previously described for the preparation of potassium dinitrodiglycinatocobaltate(III) uses the action of potassium glycinate on potassium hexanitrocobaltate-(III) The corresponding silver salt is prepared by double decomposition of the potassium salt with silver nitrate. 

Several preparations of salts of the czs-dinitrobis(ethyl-enediamine)cobalt(III) ion have been reported in the literature. The most usual is that of Werner/ modified by Holtzclaw, Sheetz, and McCarty, beginning with potassium hexanitrocobaltate(III). However, this method makes use of a starting material which is difficult to prepare in high purity and to dry thoroughly, involves critical temperature control, and produces a yield of about 15%. The following procedure, which utilizes ethylenedi-amine)cobalt(III) chloride as the starting material, provides a 60% yield of cfs-dinitrobis(ethylenediamine)cobalt-(III) nitrite. The nitrite is then easily converted to the nitrate. 

Cobaltinitrites are also complexes of Co. Addition of KNO2 to a Co solution made acid with acetic acid gives a yellow precipitate of potassium hexanitrocobaltate(III), K3Co(N02)g ... 

Penta-amminecarbonatocobalt(lll) chloride Potassium hexanitrocobaltate(lll) Tetra-aquadichlorochromium(lll) chloride Tris(ethylenediamine)platinum(IV) bromide Potassium tetrachlorocuprate(ll)... 

For analysis, the red product is dissolved in water. The resulting red solution is decolorized with oxygen and made slightly acidic with nitric acid. Aliquot portions of the solution are analyzed for potassium by precipitation of potassium hexanitrocobaltate(III), for cyanide by precipitation of silver cyanide, and for nickel by precipitation of the dime thy lgly oxime derivative. Anal. Calcd. for K4[Ni2(CN)6] K, 36.3 Ni, 27.3 CN, 36.4. Found K, 36.0 Ni, 27.1 CN, 35.8. 

Synonyms Cl pigment yellow 40 Cobaltic potassium nitrite Cobalt yellow Fischer s salt Potassium cobaltnitrate Potassium hexanitrocobaltate III... 

Potassium hexanitrocobaltate III. See Cobalt potassium nitrite Potassium hyaluronate CAS 31799-91-4... 

Synonymous with cobalt yellow (potassium hexanitrocobalt(lll) or the part-sodium substituted form) (Gates, 1995 Church, 1901). The name is derived from the Latin aureus, meaning golden (Cornman, 1986). 

Cobalt group Potassium hexanitrocobalt(Ill) Potassium sodium hexa-... 

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