Octanitrocubane

Octanitrocubane
IUPAC name Octanitrocubane
Identifiers
CAS number	99393-63-2 Y
PubChem	11762357
ChemSpider	9937054 Y
Jmol-3D images	Image 1
SMILES [O-][N+](=O)C12C3([N+]([O-])=O)C4([N+]([O-])=O)C1([N+]([O-])=O)C5([N+]([O-])=O)C2([N+]([O-])=O)C3([N+]([O-])=O)C45[N+]([O-])=O
InChI InChI=1S/C8N8O16/c17-9(18)1-2(10(19)20)5(13(25)26)3(1,11(21)22)7(15(29)30)4(1,12(23)24)6(2,14(27)28)8(5,7)16(31)32 Y Key: URIPDZQYLPQBMG-UHFFFAOYSA-N Y InChI=1/C8N8O16/c17-9(18)1-2(10(19)20)5(13(25)26)3(1,11(21)22)7(15(29)30)4(1,12(23)24)6(2,14(27)28)8(5,7)16(31)32 Key: URIPDZQYLPQBMG-UHFFFAOYAW
Properties
Molecular formula	C8N8O16
Molar mass	464.13 g/mol
Density	1.98 g/cm3
Explosive data
Shock sensitivity	Low
Friction sensitivity	Low
Explosive velocity	10,100 m/s
RE factor	2.7
Related compounds
Related compounds	Cubane Heptanitrocubane Octaazacubane
Y (verify) (what is: Y/N?) Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

Octanitrocubane (molecular formula: C₈(NO₂)₈) is a high explosive that, like TNT, is shock-insensitive (not readily detonated by shock), not detonating even when struck by a hammer.^[1] The octanitrocubane molecule has the same chemical structure as cubane (C₈H₈) except that each of the eight hydrogen atoms is replaced by a nitro group (NO₂).

It is however not as powerful as once thought, as the high density theoretical crystal structure has not been achieved. For this reason heptanitrocubane, the slightly less nitrated form, is believed to have marginally better performance despite having a worse oxygen balance.

Octanitrocubane is thought to have 20–25% greater performance than HMX (octogen), the state-of-the-art military explosive as of year 2000^[update]. This increase in power is due to its highly expansive breakdown into CO₂ and N₂, as well as to the presence of strained chemical bonds in the molecule which have stored potential energy. In addition, octanitrocubane produces no water vapor making it less visible, and both the chemical itself and its decomposition products are considered non-toxic.

Small amounts have been synthesized in the laboratory, but not enough for performance testing as an explosive.^[2]

Octanitrocubane was first synthesized by Philip Eaton (who was also the first to synthesize cubane in 1964) and Mao-Xi Zhang at the University of Chicago in 1999, with the structure proven by crystallographer Richard Gilardi of the United States Naval Research Laboratory.^[3][4]

The predicted R.E. factor is about 2.7.^{[citation needed]}

Synthesis

Although octanitrocubane is predicted to be one of the most effective explosives, the difficulty of its synthesis inhibits practical use. Philip Eaton’s synthesis was difficult and lengthy, and required cubane (rare enough to begin with) as a starting point. As a result, octanitrocubane is more valuable, gram for gram, than gold.^[5] A proposed path to synthesis is the cyclotetramerization of the as yet undiscovered and presumably unstable dinitroacetylene.^[6]

See also

• Hexanitrohexaazaisowurtzitane
• 4,4'-Dinitro-3,3'-diazenofuroxan

References

1. ^ http://www-news.uchicago.edu/releases/01/010320.explosive.shtml
2. ^ Astakhov AM, Stepanov RS, Babushkin AY (1998). "On the detonation parameters of octanitrocubane". Combustion Explosion and Shock Waves 34 (1): 85–87. doi:10.1007/BF02671823. 
3. ^ Mao-Xi Zhang, Philip E. Eaton, Richard Gilardi (2000). "Hepta- and Octanitrocubanes". Angewandte Chemie International Edition 39 (2): 401–404. doi:10.1002/(SICI)1521-3773(20000117)39:2<401::AID-ANIE401>3.0.CO;2-P. PMID 10649425. 
4. ^ Philip E. Eaton, Mao-Xi Zhang, Richard Gilardi, Nat Gelber, Sury Iyer, Rao Surapaneni (2001). "Octanitrocubane: A New Nitrocarbon". Propellants, Explosives, Pyrotechnics 27 (1): 1–6. doi:10.1002/1521-4087(200203)27:1<1::AID-PREP1>3.0.CO;2-6. 
5. ^ http://www.wiley-vch.de/books/sample/3527302409_c01.pdf
6. ^ http://www.dtic.mil/cgi-bin/GetTRDoc?Location=U2&doc=GetTRDoc.pdf&AD=ADA364287

External links

• American Chemical Society lauds difficult synthesis of new compound (by Philip Eaton), March 20, 2001