Nitroguanidine

Manufacture

Nitroguanidine is produced worldwide on a large scale starting with the reaction of dicyandiamide (DCD) with ammonium nitrate to afford the salt guanidinium nitrate, which is then nitrated by treatment with concentrated sulfuric acid at low temperature.

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The guanidinium nitrate intermediate may also be produced via the Boatright–Mackay–Roberts (BMR) process, in which molten urea is reacted with molten ammonium nitrate in the presence of silica gel. This process had been commercialized because of its attractive economic features.

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Uses

Explosives

Nitroguanidine has been in use since the 1930s as an ingredient in triple-base gun propellants in which it reduces flame temperature, muzzle flash, and erosion of the gun barrel but preserves chamber pressure due to high nitrogen content. Its extreme insensitivity combined with low cost has made it a popular ingredient in insensitive high explosive formulations (e.g AFX-453, AFX-760, IMX-101, AL-IMX-101, IMX-103, etc.).

The first triple-base propellant, featuring 20-25% of nitroguanidine and 30-45% nitroglycerine, was developed at the Dynami Nobel factory at Avigliana and patented by its director Dr. Modesto Abelli (1859-1911) in 1905.

Nitroguanidine's explosive decomposition may be given by the following idealized equation: :

Pesticides

Nitroguanidine derivatives are used as insecticides, having a comparable effect to nicotine. Derivatives include clothianidin, dinotefuran, imidacloprid, and thiamethoxam.

Structure

It has been confirmed by NMR spectroscopy, and both x-ray and neutron diffraction that nitroguanidine exclusively exists as the nitroimine tautomer both in solid state and solution.

Related compounds

The methylated and nitrosylated derivative methylnitronitrosoguanidine is used to mutagenize bacterial cells for biochemical studies.

References

References

1. (February 1954). "Spectrophotometric Studies of Dissociation Constants of Nitroguanidines, Triazoles and Tetrazoles". Journal of the American Chemical Society.
2. (December 1955). "Basic Equilibrium Constants of Nitroguanidine and Nitroaminoguanidine". Journal of the American Chemical Society.
3. (1 January 1974). "Encyclopedia of Explosives and Related Items". U.S. Army Research and Development Command TACOM - Ardec Warheads, Energetics and Combat Support Center.
4. {{Sigma-Aldrich
5. (30 March 2017). "SDS - Nitroguanidine". Santa Cruz Biotechnology.
6. Koch, Ernst-Christian. (2019). "Insensitive High Explosives: III. Nitroguanidine – Synthesis – Structure – Spectroscopy – Sensitiveness". Propellants, Explosives, Pyrotechnics.
7. (December 1973). "Process Engineering Design for Manufacture of Guanidine Nitrate". [[Picatinny Arsenal]].
8. (August 2019). "Insensitive high explosives: IV. Nitroguanidine – Initiation & detonation". Defence Technology.
9. (1960). "Encyclopedia of Explosives and Related Items". U.S. Army Research and Development Command TACOM - Ardec Warheads, Energetics and Combat Support Center.
10. {{US patent. 899855A
11. (1987). "Structure of nitroguanidine: nitroamine or nitroimine? New NMR evidence from nitrogen-15 labeled sample and nitrogen-15 spin coupling constants". Magnetic Resonance in Chemistry.
12. (2005). "Structures of nitroso- and nitroguanidine x-ray crystallography and computational analysis". Journal of Chemical Crystallography.
13. (15 October 1981). "Refinement of 2-nitroguanidine by neutron powder diffraction". Acta Crystallographica Section B Structural Crystallography and Crystal Chemistry.