Azidotetrazolate
Azidotetrazolate CN7− is a highly explosive series of salts and an anion. The ion is made by removing a proton from 5-azido-1H-tetrazole. The molecular structure contains a five membered ring with four nitrogen atoms, and a side azido chain connected to the carbon atom. Several salts exist, but they are unstable and spontaneously explode.[1] Rubidium azidotetrazolate was so unstable that it explodes while crystallizing.[1] The potassium and caesium salt also spontaneously explode when dry.[1]
Azidotetrazolates are under investigation for use as bullet propellant, rocket propellants and high explosives. The nitrogen base compounds have the advantage of being "green explosives", meaning that their waste products are safe.[1] Amongst the tetrazolates, they have the highest nitrogen fraction.[2]
Different stimuli can set off explosions. Possibilities include impact, friction, sparks or heat. Guanidinium azidotetrazolate could be melted to an ionic liquid at 100°C, but would decompose smoothly at 159°. Sodium azidotetrazolate explodes when the temperature reaches 155°C.[1]
Formation
The azidotetrazolate ion can be made from cyanogen bromide and sodium azide in water:[1]
BrCN + 2NaN3 → N4CN3− + Na+
Salts
| formula[1] | name | molecular weight | density | structure | unit dell dimension Å | cell volume | formula per cell | Specific impuse | PubChem CID |
|---|---|---|---|---|---|---|---|---|---|
| NH4CN7 | Ammonium azidotetrazolate | 128.12 | 1.608 | monoclinic | a=3.9103 b=6.9140 c=9.9127 β=99.177° | 264.57 | 2 | 248 | |
| N2H5CN7 | Hydrazinium azidotetrazolate | 143.14 | 1.568 | monoclinic | a=10.8114 b=7.4641 c=7.6676 β=101.437° | 606.47 | 4 | 265 | |
| CN3H6CN7 | guanidinium azidotetrazolate semihydrate | 358.35 | 1.546 | monoclinic | a=9.5374 b=15.3120 c=10.5731 β=94.361 | 1539.6 | 4 | ||
| CN4H7CN7 | aminoguanidinium azidotetrazolate | 185.19 | 1.524 | triclinic | a=9.7652 b=9.7803 c=10.0434 α=71.327° β=74.399° γ=63.962° | 807.2 | 4 | 228 | |
| LiCN7•H2O | Lithium azidotetrazolate monohydrate | 135.03 | 1.683 | monoclinic | a=8.9207 b=4.6663 c=12.8648 β=95.608 | 532.96 | 4 | ||
| NaCN7•H2O | sodium azidotetrazolate monohydrate | 151.09 | 1.743 | monoclinic | a=11.203 b=7.138 c=14.409 β=91.630° | 1151.8 | 8 | ||
| KCN7 | Potassium azidotetrazolate | 149.18 | 1.917 | monoclinic | a=9.7759 b=6.2990 c=8.4533 β=96.720° | 516.96 | 4 | ||
| RbCN7 | Rubidium azidotetrazolate | ||||||||
| CsCN7 | Caesium azidotetrazolate | 242.99 | 2.810 | orthorhombic | a=4.3082 b=7.1345 c=18.6869 | 574.38 | 4 | ||
| 3Ca(CN7)2•16H2O | Calcium azidotetrazolate | 1068.98 | 1.657 | monoclinic | a=24.448 b=6.616 c=28.057 β=109.246° | 4285 | 4 | ||
| AgCN7 | silver azidotetrazolate |
References
- ^ a b c d e f g Klapötke, Thomas M.; Stierstorfer, Jörg (28 January 2009). "The CN7- Anion". Journal of the American Chemical Society. 131 (3): 1122–1134. doi:10.1021/ja8077522.
- ^ Petkewich, Rachel A. "High-Nitrogen Anion Exceeds The Power Of RDX | January 12, 2009 Issue - Vol. 87 Issue 2 | Chemical & Engineering News". cen.acs.org.
External links
- Derek, Lowe (7 January 2009). "Things I Won't Work With: Azidotetrazolate Salts". In the Pipeline. Retrieved 11 February 2018.