Reaction between hexacyanoferrate(III) ion and nitric and nitrous acids. Part II. Nature of the intermediate

Abstract

The structure of an intermediate formed by reaction of nitrogen dioxide with hexacyanoferrate(III) ion is deduced to be a bridged binuclear complex, [Fe₂(CN)₉(NO)₂]^3–, on the basis of stoicheiometric, i.r., and Mössbauer evidence. A linear nitrosyl bridge is suggested. The other products, ammonia, carbon dioxide, and cyanogen all suggest that nitrogen dioxide oxidises a cyanide ligand to cyanate, which subsequently decomposes. The intermediate is formed by a disproportionate reaction between two of the [Fe(CN)₆]^3––NO₂ adducts.