Potassium cobalt ferricyanide

Potassium cobalt(II) ferricyanide [potassium cobalt(II) hexakis(cyano-ferrate(3-))] KCoii[Fe(CN)6] [14874-73-8]... 

Cobalt ferricyanide, Co3[Fe(CN)6]2 is a red precipitate resulting when potassium ferricyanide and cobalt sulphate solutions are mixed. The ammoniates Co3[Fe(CN)6]2.4NH3.6H20 11 and Co3[Fe(CN)6]2.8NH3 12 have been prepared. 

In the separation of caesium, the following inorganic cation exchangers are particularly useful potassium cobalt(II) hexacyanoferrate(II) [12,13], potassium copper(II) and nickel(II) hexacyanoferrates(II) [14], ammonium molybdophosphate [13,15], zirconium molybdoarsenate [16], thallium tungstophosphate [17], and tin molybdosilicate [18]. Rubidium has been selectively isolated on columns filled with titanium tungstoarsenate [19] or titanium ferricyanide [20]. Ammonium molybdoarsenate has been used to separate potassium from sodium [21]. 

The double compound, [Cr(NH3)6H20][Cr(CN)8], is precipitated from the aquo-pentammino-chloride on addition of potassium chromi-cyanide it separates as a sparingly soluble yellow crystalline powder, and on heating with concentrated hydrochloric acid decomposes with formation of ehloro-pentammino-chloride. The ferricyanide, [Cr(NH3)B H20][Fe(CN)6], is precipitated from a dilute solution of the aquo-pentammino-ehloride on addition of potassium ferricyanide, and crystallises in vellowish-brown prisms. The cobalti-cyanide, [Cr(NH3)5H20] [Co(CN)6], obtained, by the addition of potassium cobalti-cyanide, in yellowish-brown crystals, is isomeric with the chromi-eyanide of aquo-pentammino-cobalt, [Co(NH3)sH20][Cr(CN)6]. 

Oxidants that operate according to this one-electron oxidation mechanism include potassium ferricyanide in alkaline solution, cobalt, copper complexes with dioxygen, and some enzymes. 

More intensive dehydrogenation of primary amines having two hydrogen atoms on the adjacent carbons leads to nitriles. Such dehydrogenations are accomplished by argentic oxide cobalt peroxide [1136], nickel peroxide [936], lead tetraacetate [443, 444], sodium hypochlorite [692], potassium ferricyanide [924], and potassium ruthenate [196] (equation 513). 

Saturated aqueous potassium ferricyanide solution + 6 N hydrochloric acid Aqueous ammonium cobalt rhodanide solution + 6 N hydrochloric acid Yellow precipitate Blue precipitate... 

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