hydrazinium azide

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| IUPACName=Hydrazinium azide

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| CASNo=14662-04-5

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| SMILES = N[NH3+].[N-]=[N+]=[N-]

| StdInChI=1S/N3.H4N2/c1-3-2;1-2/h;1-2H2/q-1;/p+1

| StdInChIKey = UZXHZRFWCCZBDW-UHFFFAOYSA-O

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| H=5 | N=5

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Hydrazinium azide or hydrazine azide is a chemical compound with formula {{chem|H|5|N|5}} or {{chem|[N|2|H|5|+|]}}{{chem|[N|3|-|]}}. It is a salt of the hydrazinium cation {{chem|N|2|H|5|+}} and the azide anion {{chem|N|3|-}}. It can be seen as a derivative of hydrazine {{chem|N|2|H|4}} and hydrazoic acid {{chem|HN|3}}. It is an unstable solid.

The compound is of scientific interest because of its high nitrogen content (93% nitrogen by weight) and explosive properties.{{cite journal |last1=Chiglien |first1=G. |last2=Etienne |first2=J. |last3=Jaulmes |first3=S. |last4=Laruelle |first4=P. |title=Structure cristalline de l'azoture d'hydrazinium, N5H5 |journal=Acta Crystallographica Section B |date=15 September 1974 |volume=30 |issue=9 |pages=2229–2233 |doi=10.1107/S0567740874006790|doi-access=free |bibcode=1974AcCrB..30.2229C }}

Structure

The solid undergoes structural phase transition to a different crystalline arrangement at a pressure of 13 GPa.{{cite journal |last1=Duwal |first1=Sakun |last2=Ryu |first2=Young-Jay |last3=Kim |first3=Minseob |last4=Yoo |first4=Choong-Shik |last5=Bang |first5=Sora |last6=Kim |first6=Kyungtae |last7=Hur |first7=Nam Hwi |title=Transformation of hydrazinium azide to molecular N8 at 40 GPa |journal=The Journal of Chemical Physics |date=7 April 2018 |volume=148 |issue=13 |pages=134310 |doi=10.1063/1.5021976|pmid=29626901 |bibcode=2018JChPh.148m4310D |osti=1432864 |doi-access=free }}

Chemistry

Hydrazinium azide decomposes explosively into hydrazine, ammonia, and nitrogen gas:{{cite book | title = Thermal decomposition and combustion of explosives and propellants | author = G. B. Manelis | publisher = CRC Press | year = 2003 | isbn = 0-415-29984-5 | page = 235 | url = https://books.google.com/books?id=_Xz7_o23J_0C&pg=PA235 }}

:12 {{chem|N|5|H|5}} → 3 {{chem|N|2|H|4}} + 16 {{chem|NH|3}} + 19 {{chem|N|2}}

Crystallization with an equimolar amount hydrazine yields the solid hydrazinium azide hydrazinate, {{chem|[N|2|H|5|+|]}}{{chem|[N|3|−|]}}·{{chem|[N|2|H|4|]}}, or {{chem|N|7|H|9}}, as monoclinic crystals. This compound is less hygroscopic and less volatile than pure hydrazinium azide. It decomposes explosively into nitrogen, hydrogen, and ammonia.{{cite journal|first1=Anton |last1=Hammerl |first2=Thomas M. |last2=Klapötke |first3=Holger |last3=Piotrowski |first4=Gerhard |last4=Holl |first5=Manfred |last5=Kaiser |date=2001 |title=Synthesis and Characterization of Hydrazinium Azide Hydrazinate |journal=Propellants, Explosives, Pyrotechnics |volume=26 |issue=4 |pages=161–164 |doi=10.1002/1521-4087(200110)26:4<161::AID-PREP161>3.0.CO;2-O}}

At pressure of 40 GPa, hydrazinium azide decomposes yielding a linear nitrogen allotrope {{chem|N|8}} or N≡{{overset|+|N}}−{{overset|−|N}}−N=N−{{overset|−|N}}−{{overset|+|N}}≡N, that decomposes to ε-N₂ below 25 GPa.

Reaction of hydrazinium azide with sulfuric acid gives quantitative yields of pure hydrazinediium sulfate and hydrazoic acid:{{cite journal | last1 = Klapötke | first1 = T. | title = Reaction of hydrazinium azide with sulfuric acid: the X-ray structure of {{chem|[N|2|H|6|][SO|4|]}} | journal = Polyhedron | volume = 15 | issue = 15 | pages = 2579–2582 | year = 1996 | doi = 10.1016/0277-5387(95)00527-7 | author2 = Peter S. White | author3 = Inis C. Tornieporth-Oetting }}

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

hydrazinium azide

Structure

Chemistry

See also

References

Further reading