2-Cyanoguanidine

2-Cyanoguanidine
IUPAC name 2-Cyanoguanidine
Other names Cyanoguanidine, dicyanodiamide, N-cyanoguanidine, 1-cyanoguanidine, Guanidine-1-carbonitrile, dicyandiamin, Didin, DCD, Dicy
Identifiers
CAS number	461-58-5 Y
PubChem	10005
ChemSpider	9611 Y
EC number	207-312-8
RTECS number	ME9950000
Jmol-3D images	Image 1
SMILES N#C\N=C(/N)N
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
Properties
Molecular formula	C2H4N4
Molar mass	84.08 g/mol
Appearance	White crystals
Density	1.400 g/cm3
Melting point	209.5 °C
Boiling point	252 °C
Solubility in water	41.3 g/l
log P	-0.52
kH	2.25·10-10 atm.m³/mol
Hazards
R-phrases	R20/21/22
S-phrases	S24/25
Main hazards	harmful (Xn)
Y (verify) (what is: Y/N?) Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

2-Cyanoguanidine or commonly dicyandiamide is an nitrile derived from guanidine. It is a dimer of cyanamide, from which it can be prepared. 2-Cyanoguanidine is a colourless solid that is soluble in water, acetone, and alcohol, but not in diethyl ether or chloroform.^[1]

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. It is also used as a slow fertilizer. Formerly, it was as a fuel in some explosives. It is used in the adhesive industry as a curing agent for epoxies.

Tautomers and salts

It is possible to draw a tautomer of 2-cyanoguanidine with the structure NC-NH-C(NH)NH2. Further tautomerization gives NC-NH-C(N^-)NH3⁺. Formal loss of neutral ammonia (NH₃) from this latter tautomer followed by deprotonation gives the anion commonly referred to the dicyanamide ion, (NC)₂N^-. The dicyanamide ion has been used extensively as a counterion in the chemistry of organic and inorganic salts, for example in the synthesis of what was, in 1990, a superconductor with novel properties^[2] where we can see the anion depicted as N(CN)₂^-.

References

1. ^ Thomas Güuthner; Bernd Mertschenk (2006). "Cyanamides". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a08_139.pub2. 
2. ^ A new ambient-pressure organic superconductor, κ-(ET)₂Cu[N(CN)₂]Br, with the highest transition temperature yet observed (inductive onset T_c= 11.6 K, …, AM Kini, U Geiser, HH Wang, KD Carlson…, Inorganic Chemistry 1990, 29, 2555-2557.

External links

• International Chemical Safety Card 0650
• OECD document
• Entry at chemicalland21.com