Tetraazidomethane: chemistry with a bang

The chemistry of compounds containing multiple azide groups (N₃) has entered a renaissance in recent years. Inorganic and organic versions of polyazides are of interest as high-energy-density materials (explosives, propellants, or fireworks) and have potential uses in the fabrication of electronic devices. Klaus Banert and his coworkers at Chemnitz University of Technology, in Germany, now report the latest addition to the polyazide family: tetraazidomethane (shown, top), a carbon atom with four azide groups attached (Angew. Chem. Int. Ed., DOI: 10.1002/anie.200603960). The team made C(N₃)₄ by reacting commercially available trichloroacetonitrile (Cl₃CCN) with sodium azide (NaN₃). The tetraazide is an isolable high-boiling-point liquid that is dangerous to handle, the researchers caution. They found that C(N₃)₄ hydrolyzes readily; that it can be trapped by the double bond of norbornene (product shown, bottom); and that it reacts with phosphines to form phosphazenes.