Nitro-Iron, Fe₂(NO₂)

Attempts to prepare Nitro-iron, Fe₂(NO₂), analogous to nitro-nickel and nitro-cobalt, have been successful. It presumably results as an intermediate product when nitrogen peroxide diluted with nitrogen is passed over reduced iron. The peroxide is absorbed, but the resulting compound deflagrates even in a greatly diluted atmosphere of nitrogen peroxide. The corresponding cobalt and nickel derivatives, namely Co₂(NO₂) and Ni₂(NO₂), respectively, are considerably more stable.