Nomenclature
CAS number: 420-04-2
Carbodiimide; hydrogen cyanamide; carbimide; cyanogenamide; amidocyanogen.
CH
2N
2; mol wt 42.04.
C 28.57%, H 4.80%, N 66.64%.
H
2NC≡N.
Description and references
Prepd commercially by continuous carbonation
of calcium cyanamide in water. Ref. “Cyanamide,” Process
Chemicals Dept., Am. Cyanamid (New York, 1959) p 19. Acute toxicity
data: J. Doull et al., Survey
of Compounds for Radiation Protection (AD277689, USAF
Radiation Lab., 1962) 124 p.
Properties
Deliquescent, orthorhombic, elongated, six-sided
tablets from dimethyl phthalate. d420 1.282. mp 45-46°. bp0.5 83°. Formn of dicyandiamide begins
at 122°. Dipole moment in benzene at 20°: 3.8. Cryoscopic constant
(water) 26.8-28.4. Sp ht 0.547 cal/g/°C between 0° and 39°. Heat
of formation 14.05 kcal/mole (25°); heat of combustion -176.4 kcal/mole
(25°); heat of fusion 2.1 kcal/mole. Heat of vaporization 16.4 kcal/mole.
Soly (g/100 g soln) in water at 15°: 77.5, at 43°: 100; in butanol
at 20°: 28.8, in methyl ethyl ketone: 50.5, in ethyl acetate: 42.4.
Sol in alcohols, phenols, amines, ethers, ketones. Very sparingly
sol in benzene, halogenated hydrocarbons. Practically insol in cyclohexane.
Solid cyanamide should be stored in a cool, dry place. Polymerizes
at 122°. Optimum pH for storage of solns is ≈4. Attacks various
metals. Solns can be stored in glass provided they are stabilized
with phosphoric, acetic, sulfuric, or boric acid. LD50 i.p. in male mice: 200-300 mg/kg (Doull).Note
Term “cyanamide” is also used to designate
calcium cyanamide.Caution
Potential symptoms of overexposure
are irritation of eyes, skin, respiratory system; eye, skin burns;
miosis, salivation, lacrimation, twitching; Antabuse-like effects.
See NIOSH Pocket Guide to Chemical
Hazards (DHHS/NIOSH 97-140, 1997) p 80.