Nitryl Chloride, NO₂Cl

Nitryl Chloride, NO₂Cl, was stated to have been obtained by the action of nitrogen tetroxide on chlorine or hydrogen chloride, and by the action of chlorine on silver nitrate. Similarly, nitryl bromide, NO₂Br, was considered to be the product of the action of bromine on nitrogen tetroxide. Later investigations, however, appeared to disprove the formation of these halogen compounds by the above methods. More recently, it is claimed that nitryl chloride is formed when nitric acid reacts with phosphorus oxychloride, and nitryl bromide by passing nitrogen tetroxide and bromine vapour over a catalyst of calcined lime heated to 200°-250° C.