Potassium nitrogen trioxide

The dinitro-tetrachlor-iridite salt, K3IrCl4. (N02)2, results on treating ammonium chloriridate suspended in water with nitrogen trioxide, and then adding the requisite quantity of potassium chloride.6 It crystallises out as golden yellow crystals, very soluble in water. When boiled with potassium nitrite it yields the trmitro-trichlor derivative, K3IrCl3(NOa)3. 

For the preparation of chlorides or bromides, the diazonium salt is decomposed with a solution of cuprous chloride or bromide in the corresponding halogen acid (Sandmeyer reaction). It is possible to prepare the aryl bromide from the diazonium chloride or sulfate. A variation Involves the use of copper powder and a mineral acid for the decomposition step (Gattermann reaction). Both procedures are illustrated by the syntheses of the isomeric bromotoluenes and chlorotoluenes. The usual conditions of the Sandmeyer reaction fail in the preparation of the chloro- and bromo-phenanthrenes. However, these compounds can be successfully obtained by the interaction of the diazonium compound with mercuric and potassium halides (Schwechten procedure). Another procedure for formation of aryl bromides involves treatment of the amine hydrobromide with nitrogen trioxide in the presence of excess 40% hydro-bromic acid. The Intermediate diazonium perbromide is then decomposed by heat. ... 

Nitrogen trichloride detonates in the presence of nitrogen monoxide, dioxide or trioxide and also in contact with ammonia and potassium cyanide. 

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