Nitrate nitrite

A nitrate nitrite, or nitrite nitrate, is a coordination complex or other chemical compound that contains both nitrite (NO2−) and nitrate (NO3−) anions. They are mixed-anion compounds, and they are mixed-valence compounds. Some have third anions. Many nitrite nitrate compounds are coordination complexes of cobalt. Such a substance was discovered by Wolcott Gibbs and Frederick Genth in 1857.

Production
Mercury(II) nitrate and potassium nitrate in water solution produce the salt tripotassium tetranitratomercurate(II) nitrate K3[Hg(NO2)4]NO3.

Properties
On heating, nitrate nitrites lose NO2 and NO and yield metal oxides.

Related
Other compounds having an element in two different anion states include the sulfate sulfites, the phosphate phosphites, arsenate arsenites and the selenate selenites.