Nitroguanidine

Nitroguanidine
Names
	IUPAC name 1-Nitroguanidine
	Other names Picrite
Identifiers
CAS Number	556-88-7 ;
3D model (JSmol)	Interactive image;
ChEBI	CHEBI:39180 ;
ChemSpider	10701 ;
ECHA InfoCard	100.008.313
PubChem CID	11174;
UNII	NAY6KWL67F ;
CompTox Dashboard (EPA)	DTXSID4024222 ;
	InChI InChI=1S/CH4N4O2/c2-1(3)4-5(6)7/h(H4,2,3,4) Key: IDCPFAYURAQKDZ-UHFFFAOYSA-N ; InChI=1/CH4N4O2/c2-1(3)4-5(6)7/h(H4,2,3,4) Key: IDCPFAYURAQKDZ-UHFFFAOYAN;
	SMILES NC(N)=N[N+]([O-])=O;
Properties
Chemical formula	CH4N4O2
Molar mass	104.07 g/mol
Appearance	Colorless crystalline solid
Density	1.77 g/cm3
Melting point	257 °C (495 °F; 530 K)
Solubility in water	3.45 g/kg (in water at 25 °C)
Explosive data
Shock sensitivity	> 50 J
Friction sensitivity	> 350 N
RE factor	1.00
Hazards
Main hazards	Explosive
Related compounds
Related compounds	Guanidine; Guanidine nitrate
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
	(what is ?)
	Infobox references

Nitroguanidine- abbreviated NGu or NQ- is a colorless, crystalline solid that melts at 257 °C and decomposes at 254 °C. NGu is an extremely insensitive but powerful high explosive. Wetting NGu with > 20 wt.-% water effects desensitization from HD 1.1 down to HD 4.1 (flammable solid).^[1] NGu is used as an energetic material (propellants, High explosives), precursor for insecticides, and for other purposes.

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, GN. GN is nitrated by treatment with concentrated sulfuric acid at low temperature.^[2]

[C(NH₂)₃]NO₃ → (NH₂)₂CNNO₂ + H₂O

Nitroguanidine can also be generated by treatment of urea with ammonium nitrate (BMR-process). However, owing to problems of reliability and safety, this process has never been commercialized despite its attractive economic features.

Uses[]

Explosives[]

Nitroguanidine is 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 NGu become a popular ingredient in insensitive high explosive formulations (e.g AFX-453, AFX-760, IMX-101, AL-IMX-101, IMX-103, etc.).^[3]

Nitroguanidine's explosive decomposition is given by the following equation: H₄N₄CO_{2 (s)} → 2 H₂O_(g) + 2 N_{2 (g)} + C_(s)

Pesticides[]

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

Biochemistry[]

The nitrosoylated derivative nitrosoguanidine is often used to mutagenize bacterial cells for biochemical studies.

Structure[]

Following several decades of debate, it could be confirmed by NMR-spectroscopy, X-ray and neutron diffraction that nitroguanidine exclusively exists as the tautomer both in solid state and solution.^[4]^[5]^[6]

References[]

^ United Nations, Transport of Nitroguanidine, wetted, (UN 1336) in flexible IBCs, ST/SC/AC.10/C.3/2006/52, Geneva, 13 April 2006. Accessed at https://www.unece.org/fileadmin/DAM/trans/doc/2006/ac10c3/ST-SG-AC10-C3-2006-52e.pdf
^ E.-C. Koch, Insensitive High Explosives: III. Nitroguanidine – Synthesis – Structure – Spectroscopy – Sensitiveness, Propellants Explos. Pyrotech. 2019, 44, 267-292. [1]
^ E.-C. Koch, Insensitive High Explosives: IV. Nitroguanidine - Initiation & detonation, Def. Tech. 2019, 15, 467-487.[2]
^ Bulusu, S.; Dudley, R. L.; Autera, J. R. (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. 25 (3): 234–238. doi:10.1002/mrc.1260250311. S2CID 97416890.
^ Murmann, R. K.; Glaser, Rainer; Barnes, Charles L. (2005). "Structures of nitroso- and nitroguanidine x - ray crystallography and computational analysis". Journal of Chemical Crystallography. 35 (4): 317–325. doi:10.1007/s10870-005-3252-y. S2CID 96090647.
^ S. Choi, Refinement of 2-Nitroguanidine by Neutron Powder Diffraction, Acta Crystallogr. B 1981, 37, 1955-1957.[3]

[1] United Nations, Transport of Nitroguanidine, wetted, (UN 1336) in flexible IBCs, ST/SC/AC.10/C.3/2006/52, Geneva, 13 April 2006. Accessed at https://www.unece.org/fileadmin/DAM/trans/doc/2006/ac10c3/ST-SG-AC10-C3-2006-52e.pdf

[2] E.-C. Koch, Insensitive High Explosives: III. Nitroguanidine – Synthesis – Structure – Spectroscopy – Sensitiveness, Propellants Explos. Pyrotech. 2019, 44, 267-292. [1]

[3] E.-C. Koch, Insensitive High Explosives: IV. Nitroguanidine - Initiation & detonation, Def. Tech. 2019, 15, 467-487.[2]

[4] Bulusu, S.; Dudley, R. L.; Autera, J. R. (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. 25 (3): 234–238. doi:10.1002/mrc.1260250311. S2CID 97416890.

[5] Murmann, R. K.; Glaser, Rainer; Barnes, Charles L. (2005). "Structures of nitroso- and nitroguanidine x - ray crystallography and computational analysis". Journal of Chemical Crystallography. 35 (4): 317–325. doi:10.1007/s10870-005-3252-y. S2CID 96090647.

[6] S. Choi, Refinement of 2-Nitroguanidine by Neutron Powder Diffraction, Acta Crystallogr. B 1981, 37, 1955-1957.[3]

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