Nitrotriazolone (NTO) is a heterocyclic semicarbazide-derived high explosive first identified in 1905, but research into its explosive properties was not conducted until the 1980s.[2] NTO is currently being used by the US Army in munitions, specifically Insensitive munitions replacing those made with legacy explosives.[3]
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| Names | |
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| Preferred IUPAC name
5-Nitro-1,2-dihydro-3H-1,2,4-triazin-3-one | |
| Identifiers | |
3D model (JSmol)
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| Abbreviations | NTO |
| ChemSpider | |
| ECHA InfoCard | 100.012.050 |
| EC Number |
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| MeSH | C420648 |
PubChem CID
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| UNII | |
| UN number | 0490 |
CompTox Dashboard (EPA)
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| Properties | |
| C2H2N4O3 | |
| Molar mass | 130.063 g·mol−1 |
| Appearance | Off white, yellowish beige color to light yellow powder, crystals, or prills |
| Odor | Odourless |
| Density | 1.9 g/cm3 (20 °C) |
| Melting point | 268–271 °C (514–520 °F; 541–544 K) |
| 17,200 mg/L | |
| Solubility | Soluble in acetone, ethyl acetate Slightly soluble in dichloromethane |
| log P | -1.699 (22 °C) |
| Acidity (pKa) | 3.76 (20 °C) |
| Explosive data | |
| Shock sensitivity | Very low |
| Friction sensitivity | Very low |
| Detonation velocity | 8,500 m/s |
| Thermochemistry | |
Heat capacity (C)
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124.5 J/K at (47 °C) |
Std enthalpy of
combustion (ΔcH⦵298) |
-934.4 kJ/mol |
| Hazards | |
| GHS labelling: | |
   
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| Danger | |
| H209, H223, H242, H301, H313, H315, H319, H333, H335 | |
| P210, P220, P260, P262, P270, P280 | |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Nitrotriazolone is being progressively made use of in novel explosive formulations, such as IMX-101, a new, safer alternative to TNT specially devised in 2010 by BAE Systems, where it is combined with 2,4-dinitroanisole and nitroguanidine. As such, NTO is found in the vast majority of IMX formulations. The Picatinny Arsenal has also adopted the implementation of NTO and DNAN in many of their likewise newly developed insensitive explosive mixtures, which share many of the same applications of the IMXs. [4]
Properties
editNitrotriazolone shows keto–enol tautomerism through proton transfer reactions. The keto form shows significantly different stability to heat, friction, and impact.[5]
Nitrotriazolone can form either a mono or dihydrate.[5]
Preparation
editNTO was first made in 1905[6] in a two step process. Semicarbazide hydrochloride is condensed with formic acid to produce 1,2,4-triazol-3-one, which is nitrated with nitric acid to form nitrotriazolone.[7][5]
Toxicity
editIn vivo studies showed the nitrotriazolone is absorbed through the skin and gastrointestinal tract. In the kidneys, NTO is broken down into 5-amino-1,2,4-triazol-3-one, which undergoes oxidative denitrification and forms urazoles and nitrites in rats.[8]
References
edit- ^ "Nitrotriazolone". PubChem. National Institutes of Health. Archived from the original on 17 November 2016. Retrieved 16 November 2016.
- ^ Jai Prakash Agrawal (20 November 2015). High Energy Materials: Propellants, Explosives and Pyrotechnics. Wiley. pp. 124–. ISBN 978-3-527-80268-5. Archived from the original on 25 January 2021. Retrieved 20 August 2019.
- ^ Winstead, Bob (26 October 2011). "Nitrotriazolone: An Environmental Odyssey" (PDF). NDIA Systems Engineering Conference. Archived from the original (PDF) on 13 December 2016. Retrieved 16 November 2016.
- ^ Shree Nath Singh (4 August 2013). Biological Remediation of Explosive Residues. Springer Science & Business Media. pp. 285–. ISBN 978-3-319-01083-0. Archived from the original on 25 January 2021. Retrieved 20 August 2019.
- ^ a b c Wei, Rongbin; Fei, Zhongjie; Yoosefian, Mehdi (August 2021). "Water molecules can significantly increase the explosive sensitivity of Nitrotriazolone (NTO) in storage and transport". Journal of Molecular Liquids. 336: 116372. doi:10.1016/j.molliq.2021.116372. S2CID 235575519.
- ^ W. Manchot; R. Noll (1905). "Ueber Derivate des Triazols". Justus Liebigs Annalen der Chemie. 343 (1): 1–27. doi:10.1002/JLAC.19053430102. ISSN 0075-4617. Wikidata Q56659145.
- ^ Mukundan, T.; Purandare, G. N.; Nair, J. K.; Pansare, S. M.; Sinha, R. K.; Singh, Haridwar (2002-04-01). "Explosive Nitrotriazolone Formulates". Defence Science Journal. 52 (2): 127–133. doi:10.14429/dsj.52.2157. Archived from the original on 2023-01-29. Retrieved 2022-04-17.
- ^ "1,2-dihydro-5-nitro-3H-1,2,4-triazol-3-one". European Chemical Agency. Retrieved 2022-04-16.
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