Potassium cobaltinitrite

Evaporation by heating a filtrate from precipitation of potassium cobaltinitrite caused it to turn purple and explode violently [1]. This was attributed to interaction of nitrite, nitrate, acetic acid and residual cobalt with formation of fulminic or methylnitrolic acids or their cobalt salts, all of which are explosive [2], Mixtures containing nitrates, nitrites and organic materials are potentially dangerous, especially in presence of acidic materials and heavy metals. A later publication confirms the suggestion of formation of nitro- or nitrito-cobaltate(III) [3],... 

To a little of the filtrate from the crystals, add a solution of a potassium salt, observing the instant precipitation of the insoluble potassium cobaltinitrite. An excess added to all of the mother liquors will give a preparation... 

Cobalt Nitrite Complexes. When KNOz is added in excess to a soln of Co(NOa)2,acidified with AcOH, a yel ppt of potassium hexa-nitrocobaltiate (potassium cobaltinitrite),... 

More rarely use is made for the same purpose of other substances such as strontium and calcium chromates, lead oxychloride (Cassel yellow), lead protoxide, arsenic sulphide (orpiment), stannic sulphide (mosaic gold), potassium cobaltinitrite (cobalt yellow), etc. 

Sodium rhodinitrite dissolves in 2 times its weight of water at 17° C., and in one part of boiling water. It is thus considerably more soluble than its potassium analogue. Its solution, however, does not give the reactions for rhodium, which suggests that it is a rhodinitrite, Na3Rh(N02)6, analogous to potassium cobaltinitrite. 

All salts of sodium, potassium, and ammonium are soluble except NaSb(OH),. (sodium antimonate), KoPtCl (potassium hexachloro-platinate), (NH4).,PtCl,p K3Co(NO.,),i (potassium cobaltinitrite), and (NH4),Co(N02),. ... 

Cobaltic ion is unstable, and an attempt to oxidize cobaltous ion usually leads to the precipitation of cobaltic hydroxide, Co(OH)3. The covalent cobaltic compounds are very stable. The most important ot these are potassium cobaltinitrite, KgCo(N02)6> and potassium cobalti-cyanide, K3Co(CN). ... 

Properties of cobalt. Ores—smaltite, cobaltite. Alnico and other alloys, Cobaltous chloride, cobaltous oxide, cobaltic hydroxide, potassium cobaltinitrite, potassium cobalticyanide. Cobalt glass. 

Cobaltic Potassium Nitrite, Hexakis(nitrito-N)co-baltateiJ—) tripotassium potassium hexanitrocobaltateOll) potassium cobaltinitrite potassium nitrocobaltate(lll) cobalt yellow Fischer s yellow C.l. Pigment Yellow 40 C.I. 77357. CoKjNjOmol wt 452.29. Co 13.03%, K 25.93%, N 18.58%, 0 42.45%. K3Co(N02)6. incorrectly called Indian yellow". Prepd by addition of KNO, to a solution of a Co salt Salyer, Sweet, Anal. Chem. 32, 548 (1962). 

Aureolin n. Potassium cobaltinitrite yellow pigment. Syn Cobalt yellow. 

Potassium hexanitritocobalt(III), potassium cobaltinitrite, reacts with an aqueous solution of ethylenediamine fairly rapidly at ca 70 °C to give cis-dinitrobis(ethylenediamine)cobalt(III) ... 

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