Polyazide Chemistry: Synthesis and Properties of [Nb(N3)7]2- and [Ta(N3)7]2- (PREPRINT)

During the last decade, inorganic polyazido compounds have received much attention. Besides being of academic interest, azides and polyazides are viable candidates for high energy-density materials HEDM. The azido group is very energetic and polyazides are highly endothermic compounds, whose energy content increases with an increasing number of azido ligands. It is, therefore, not surprising that the synthesis of molecules with a high number of azido groups is very challenging due to their explosive nature and shock sensitivity. Despite such obstacles, a number of pentaazido and anionic hexaazido compounds had been reported. Very recently, unprecedented neutral hexaazido species MN36 M Mo, W have been prepared, and in case of WN36 also structurally characterized. Treatment of MN36 M Mo, W with ionic azides yielded the first binary heptaazido compounds.