Potassium hexanitritocobaltate(III) is a salt with the formula K₃ o(NO₂)₆ It is a yellow solid that is poorly soluble in water. The compound finds some use as a yellow pigment under the name Indian Yellow. The salt features potassium cations and an trianionic

coordination complex A coordination complex is a chemical compound consisting of a central atom or ion, which is usually metallic and is called the ''coordination centre'', and a surrounding array of chemical bond, bound molecules or ions, that are in turn known as ' ...

. In the anion, cobalt is bound by six nitrito ligands, the overall complex having

octahedral molecular geometry In chemistry, octahedral molecular geometry, also called square bipyramidal, describes the shape of compounds with six atoms or groups of atoms or ligands symmetrically arranged around a central atom, defining the vertices of an octahedron. The o ...

. The oxidation state of cobalt is 3+. Its low-spin d⁶ configuration confers kinetic stability and diamagnetism. The compound is prepared by combining cobalt(II) and nitrite salts in the presence of oxygen. The corresponding sodium cobaltinitrite is significantly more soluble in water. The compound was first described in 1848 by Nikolaus Wolfgang Fischer in Breslau, and it is used as a yellow pigment called Aureolin.

References

Potassium compounds Cobalt(III) compounds Nitrites Cobalt complexes {{inorganic-compound-stub

See also

References