2-Cyanoguanidine

2-Cyanoguanidine

Names
IUPAC name 2-Cyanoguanidine
Other names Cyanoguanidine Dicyandiamide Dicyanodiamide N-cyanoguanidine 1-cyanoguanidine Guanidine-1-carbonitrile Didin DCD Dicy
Identifiers
CAS Number	461-58-5  Y
3D model (JSmol)	Interactive image isomer: Interactive image zwitterion: Interactive image
ChEBI	CHEBI:147423
ChemSpider	9611  Y
ECHA InfoCard	100.006.649
EC Number	207-312-8
PubChem CID	10005
RTECS number	ME9950000
UNII	M9B1R0C16H  Y
CompTox Dashboard (EPA)	DTXSID1020354
InChI InChI=1S/C2H4N4/c3-1-6-2(4)5/h(H4,4,5,6) Y Key: QGBSISYHAICWAH-UHFFFAOYSA-N Y InChI=1/C2H4N4/c3-1-6-2(4)5/h(H4,4,5,6) Key: QGBSISYHAICWAH-UHFFFAOYAY
SMILES N#CNC(=N)N isomer:N#CN=C(N)N zwitterion:N#CN=C([NH-])[NH3+]
Properties
Chemical formula	C2H4N4
Molar mass	84.082 g·mol−1
Appearance	White crystals
Density	1.4 g/cm3
Melting point	209.5 °C (409.1 °F; 482.6 K)
Boiling point	252 °C (486 °F; 525 K)
Solubility in water	41.3 g/L [1]
Solubility in acetone	soluble
Solubility in ethanol	soluble
log P	−1.5 (est) [2]
Henry's law constant  (kH)	2.25×10−10 (atm·m3)/mol[ citation needed ]
Acidity (pKa)	14.8 [1]
Basicity (pKb)	14.4 [1]
Magnetic susceptibility (χ)	−44.55×10−6 cm3/mol[ citation needed ]
Hazards [3]
Lethal dose or concentration (LD, LC):
LD50 (median dose)	>30000 mg/kg (oral, rat) [4]
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Y  verify  (what is  YN ?) Infobox references

2-Cyanoguanidine is a nitrile derived from guanidine. It is a dimer of cyanamide, from which it can be prepared.

Production and use

2-Cyanoguanidine is produced by treating cyanamide with base. It is produced in soil by decomposition of cyanamide. A variety of useful compounds are produced from 2-cyanoguanidine, guanidines and melamine. For example, acetoguanamine and benzoguanamine are prepared by condensation of cyanoguanidine with the nitrile: ^{[5] [6]}

(H₂N)₂C=NCN + PhCN → 1,3-(H₂N)-5-Ph(C₃N₃)

Cyanoguanidine is also used as a nitrification inhibitor in stabilized nitrogen fertilizers. ^[1] It is used in the adhesive industry as a curing agent for epoxy resins. ^[1] Formerly, it was used as a fuel in some explosives, and may be used as a stabilizer for nitrocellulose. ^[7]

It was patented for use in the synthesis of methylphenobarbital. ^[8]

Chemistry

The structure has been confirmed by X-ray crystallography. ^[9] The molecule is planar with two primary amine groups attached to an imino nitrile. According to Raman spectroscopy measurements, solutions also contain a tautomer, (H₂N)HN=CN(H)CN. ^[10]

2-cyanoguanidine is isomeric to ammonium dicyanamide, from which it may be prepared by heating in a closed vessel. ^{[1] [11]} The reaction proceeds via a zwitterionic intermediate, analogous to the Wöhler synthesis of urea from ammonium cyanate. ^[11]

References

1. Güthner, Thomas; Mertschenk, Bernd. "Cyanamides". Ullmann's Encyclopedia of Industrial Chemistry . Weinheim: Wiley-VCH. doi:10.1002/14356007.a08_139.pub2. ISBN   978-3-527-30673-2.
2. International Chemical Safety Card 0650
3. Sigma-Aldrich Co., Dicyandiamide.
4. Sakai, akira (30 January 2004). SIDS Initial Assessment Report, Cyanoguanidine (PDF). SIAM 17. Arona, Italy: UNEP Publications. Archived from the original (PDF) on 2017-05-17. Retrieved 24 October 2025.
5. Deim, H.; Matthias, G.; Wagner, R. A. "Amino Resins". Ullmann's Encyclopedia of Industrial Chemistry . Weinheim: Wiley-VCH. doi:10.1002/14356007.a02_115.pub2. ISBN   978-3-527-30673-2.
6. Simons, J. K.; Saxton, M. R. (1953). "Benzoguanamine". Org. Synth. 33: 13. doi:10.15227/orgsyn.033.0013 ; Coll. Vol., vol. 4, 1963, p. 78.
7. Fedoroff, Basil T.; Sheffield, Oliver E. (1 January 1966). Encyclopedia of Explosives and Related Items: Volume 3 - Chlorides through Detonating Relays (PDF). Dover, NJ: Picatinny Arsenal. p. C-587. AD0653029. Retrieved 25 October 2025.
8. Ludwig Taub and Walter Kropp, U.S. patent 2,061,114 (1936 to Winthrop Chemical Company Inc.).
9. Hirshfeld, F. L.; Hope, H. (1980). "An X-ray determination of the charge deformation density in 2-cyanoguanidine". Acta Crystallographica Section B Structural Crystallography and Crystal Chemistry. 36 (2): 406–415. Bibcode:1980AcCrB..36..406H. doi:10.1107/S0567740880003366.
10. Alı́a, J.M.; Edwards, H.G.M.; Garcı́a Navarro, F.J. (2001). "The imino–amino tautomeric equilibrium in cyanoguanidine dissolved in several aprotic solvents; an FT-Raman spectroscopic study". Journal of Molecular Structure. 597 (1–3): 49–55. Bibcode:2001JMoSt.597...49A. doi:10.1016/S0022-2860(01)00579-8.
11. Lotsch, Bettina V.; Senker, Jürgen; Schnick, Wolfgang (1 February 2004). "Characterization of the Thermally Induced Topochemical Solid-State Transformation of NH₄[N(CN)₂] into NCN=C(NH₂)₂ by Means of X-ray and Neutron Diffraction as Well as Raman and Solid-State NMR Spectroscopy" (PDF). Inorganic Chemistry. 43 (3): 895–904. doi:10.1021/ic034984f. Archived from the original (PDF) on 11 August 2017.