Hydrazinium azide explained

Hydrazinium azide or hydrazine azide is a chemical compound with formula or . It is a salt of the hydrazinium cation and the azide anion . It can be seen as a derivative of hydrazine and hydrazoic acid . It is an unstable solid.

The compound is of scientific interest because of its high nitrogen content (93% nitrogen by weight) and explosive properties.^[1]

Structure

The solid undergoes structural phase transition to a different crystalline arrangement at a pressure of 13 GPa.^[2]

Chemistry

Hydrazinium azide decomposes explosively into hydrazine, ammonia, and nitrogen gas:^[3]

12 → 3 + 16 + 19

Crystallization with an equimolar amount hydrazine yields the solid hydrazinium azide hydrazinate, ·, or, as monoclinic crystals. This compound is less hygroscopic and less volatile than pure hydrazinium azide. It decomposes explosively into nitrogen, hydrogen, and ammonia.^[4]

At pressure of 40 GPa, hydrazinium azide decomposes yielding a linear nitrogen allotrope or N≡−−N=N−−≡N, that decomposes to ε-N₂ below 25 GPa.^[2]

Reaction of hydrazinium azide with sulfuric acid gives quantitative yields of pure hydrazinediium sulfate and hydrazoic acid:^[5]

[{{chem|N|2|H|5|+}}][{{chem|N|3|−}}] + H₂SO₄ → [{{chem|N|2|H|6|2+}}][{{chem|SO|4|2−}}] + HN₃

See also

• Ammonium azide,

Notes and References

1. Chiglien . G. . Etienne . J. . Jaulmes . S. . Laruelle . P. . Structure cristalline de l'azoture d'hydrazinium, N5H5 . Acta Crystallographica Section B . 15 September 1974 . 30 . 9 . 2229–2233 . 10.1107/S0567740874006790. free .
2. Duwal . Sakun . Ryu . Young-Jay . Kim . Minseob . Yoo . Choong-Shik . Bang . Sora . Kim . Kyungtae . Hur . Nam Hwi . Transformation of hydrazinium azide to molecular N8 at 40 GPa . The Journal of Chemical Physics . 7 April 2018 . 148 . 13 . 134310 . 10.1063/1.5021976. 29626901 . 2018JChPh.148m4310D . 1432864 . free .
3. Book: Thermal decomposition and combustion of explosives and propellants . G. B. Manelis . CRC Press . 2003 . 0-415-29984-5 . 235 .
4. Anton . Hammerl . Thomas M. . Klapötke . Holger . Piotrowski . Gerhard . Holl . Manfred . Kaiser . 2001 . Synthesis and Characterization of Hydrazinium Azide Hydrazinate . Propellants, Explosives, Pyrotechnics . 26 . 4 . 161–164 . 10.1002/1521-4087(200110)26:4<161::AID-PREP161>3.0.CO;2-O.
5. Klapötke . T. . Reaction of hydrazinium azide with sulfuric acid: the X-ray structure of . Polyhedron . 15 . 15 . 2579–2582 . 1996 . 10.1016/0277-5387(95)00527-7 . Peter S. White . Inis C. Tornieporth-Oetting .