2-Cyanoguanidine
Chemical compound
From Wikipedia, the free encyclopedia
2-Cyanoguanidine is a nitrile derived from guanidine. It is a dimer of cyanamide, from which it can be prepared.
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| Names | |||
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| Preferred IUPAC name
N′′-Cyanoguanidine | |||
Other names
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| ECHA InfoCard | 100.006.649 | ||
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| Properties | |||
| 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) | ||
| 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] | ||
| −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).
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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]