Cobalto-cobalti-tri-nitrite, 2CoO.Co₂O₃.3N₂O₃

On passing nitrous oxide into a suspension of cobalt carbonate in water a brown solution of Cobalto-cobalti-tri-nitrite, 2CoO.Co₂O₃.3N₂O₃.xH₂O, is obtained from which small, almost black crystals separate on concentration at room temperature. These are usually contaminated with red crystals of cobalt nitrate. Analysis shows the crystals to have the composition

2CoO.Co₂O₃.3N₂O₃ + Co(NO₃)₂ + 14H₂O.

It is uncertain whether the cobalt nitrate is an integral part of the molecule or simply an accidental impurity.