The salt features potassium cations and an trianionic coordination complex.

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

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.

[2] The compound was first described in 1848 by Nikolaus Wolfgang Fischer in Breslau,[3] and it is used as a yellow pigment called Aureolin.