5,5′‐Hydrazinebistetrazole: An Oxidation‐stable Nitrogen‐rich Compound and Starting Material for the Synthesis of 5,5′‐Azobistetrazolates

All 5,5′‐hydrazinebistetrazoles reported in the literature are sensitive to oxidation and react with atmospheric oxygen to yield the corresponding 5,5′‐azobistetrazolates on time. Herewith, we report on the synthesis of the free acid 5,5′‐hydrazinebistetrazole (HBT) which showed to be stable on air for extended periods of time. The compound was fully characterized by analytical and spectroscopic methods and its X‐ray structure was determined by diffraction techniques. Besides, we determined its explosive properties by BAM methods and calculated its heat of formation (+414 kJ mol −1 ), detonation velocity (8523 m s −1 ) and detonation pressure (27.7 GPa). HBT proved to be very safe to handle (impact sensitivity: >30 J, friction sensitivity: ∼108 N) and was used as a starting material for the synthesis of some already reported 5,5′‐azobistetrazolates: NH 4 + , NH 2 NH 3 + , Li + , Na + , K + , Rb + , Cs + , Mg 2+ , Ca 2+ , Sr 2+ and Ba 2+ .