1215. Biguanide

Nomenclature

CAS number: 56-03-1
Imidodicarbonimidic diamide; guanylguanidine; amidinoguanidine; diguanide.
C2H7N5; mol wt 101.11.
C 23.76%, H 6.98%, N 69.26%.

Description and references

Preparation from dicyanodiamide: Rackmann, Ann. 376, 169 (1910); Karipides, Fernelius, Inorg. Synth. 7, 56, 58 (1963). Crystal structure: S. R. Ernst, F. W. Cagle, Acta Crystallogr. 33B, 235 (1977); S. R. Ernst, ibid. 237.

Chemical structure

Properties

Crystals from alc, mp 130°; dec rapidly at about 142°. Sol in water, alcohol. Insol in ether, benzene, chloroform. The aq soln dec on standing or heating. Aq solns are alkaline. Biguanide is a stronger base (pK1 = 11.52; pK2 = 2.93) than ammonia (pK = 9.61).

Derivative

Hydrochloride.
C2H7N5.HCl; mol wt 137.57.
C 17.46%, H 5.86%, N 50.91%, Cl 25.77%.

Properties

Needles, mp 235°, very sol in water, slightly sol in alc.

Derivative

Neutral sulfate.
(C2H7N5)2.H2SO4.2H2O; mol wt 336.33.
C 14.28%, H 5.99%, N 41.65%, S 9.53%, O 28.54%.

Properties

Large crystals, sol in water.

Derivative

Acid sulfate.
C2H7N5.H2SO4.H2O; mol wt 217.20.
C 11.06%, H 5.10%, N 32.24%, S 14.76%, O 36.83%.

Properties

Rhombic prisms, sol in water, the soln giving an acid reaction.

Use

Sulfates in the determination of copper and nickel.