Octaazacubane

Octaazacubane

Names
Other names Octaazapentacyclo[4.2.0.02,5.03,8.04,7]octane; Cubaazane; Nitrogen octaatomic molecule
Identifiers
CAS Number	78998-15-9 Y
3D model (Jmol)	Interactive image
SMILES N12N3N4N1N5N4N3N52
Properties
Chemical formula	N8
Molar mass	112.06 g·mol−1
Density	2.69 g/cm3 (predicted)[1]
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Infobox references

Octaazacubane is a hypothetical allotrope of nitrogen with formula N₈, whose molecules have eight atoms arranged into a cube. (By comparison, nitrogen usually occurs as the diatomic molecule N₂.) It can be regarded as a cubane-type cluster, where all eight corners are nitrogen atoms bonded along the edges.^[2] It is predicted to be a metastable molecule, in which despite the thermodynamic instability caused by bond strain, and the high energy of the N–N single bonds, the molecule remains kinetically stable for reasons of orbital symmetry.^[3]

Explosive and fuel

Octaazacubane is predicted to have an energy density (assuming decomposition into N₂) of 22.9 MJ/kg,^[4] which is over 5 times the standard value of TNT. It has therefore been proposed (along with other exotic nitrogen allotropes) as an explosive, and as a component of high performance rocket fuel.^[5] Its velocity of detonation is predicted to be 15,000 m/s, much (48.5%) more than octanitrocubane, the fastest known nonnuclear explosive.^[1]

Cubic gauche nitrogen has an energy density of 33 MJ/kg exceeding octaazacubane by 50%.^[6]

See also

• Tetranitrogen (Nitrogen allotrope with formula N₄)
• Hexazine (Nitrogen allotrope with formula N₆)
• Azidopentazole (Nitrogen allotrope with formula N₈)
• Bispentazole (Nitrogen allotrope with formula N₁₀)^[7]
• Bis(pentazolyl)diazene (Nitrogen allotrope with formula N₁₂)
• Eicosaazadodecahedrane (Nitrogen allotrope with formula N₂₀)^[8]
• Hexacontaazabuckminsterfullerene (Nitrogen allotrope with formula N₆₀)^[9][10]
• Pentazole
• 1,1′-Azobis-1,2,3-triazole

References

1. 1 2 Agrawal, Jai Prakash (2010). High Energy Materials: Propellants, Explosives and Pyrotechnics. Wiley-VCH. p. 498. ISBN 978-3-527-62880-3. 
2. ↑ B. Muir. "Cubane"(See under "further topics" section.) 
3. ↑ Patil, Ujwala N.; Dhumal, Nilesh R.; Gejji, Shridhar P. "Theoretical studies on the molecular electron densities and electrostatic potentials in azacubanes". Theoretical Chemistry Accounts: Theory, Computation, and Modeling (Theoretica Chimica Acta). 112. p. 27–32. doi:10.1007/s00214-004-0551-2. 
4. ↑ Glukhovtsev, Mikhail N.; Jiao, Haijun; Schleyer, Paul von Ragué. "Besides N₂, What Is the Most Stable Molecule Composed Only of Nitrogen Atoms?". Inorganic Chemistry. 35. p. 7124–7133. doi:10.1021/ic9606237. 
5. ↑ "Exploding the mysteries of nitrogen.". Chemistry and Industry. 
6. ↑ Yoo, Choong-Shik (February 2003). "Novel Functional Extended Solids at Extreme Conditions". DTIC. p. 11. Retrieved 5 October 2015. 
7. ↑ Manaa, M. R. (2000). "Toward new energy-rich molecular systems: From N₁₀ to N₆₀". Chemical Physics Letters. 331 (2–4): 262–268. doi:10.1016/S0009-2614(00)01164-7. 
8. ↑ Charkin, O. P. (2013). "Theoretical study of N₂₀, C₂₀, and B₂₀ clusters "squeezed" inside icosahedral C₈₀ and He₈₀ cages". Russian Journal of Inorganic Chemistry. 58: 46–55. doi:10.1134/S0036023613010038. 
9. ↑ Wang, L. J.; Zgierski, M. Z. (2003). "Super-high energy-rich nitrogen cluster N₆₀". Chemical Physics Letters. 376 (5–6): 698. doi:10.1016/S0009-2614(03)01058-3. 
10. ↑ https://www.llnl.gov/str/June01/Manaa.html