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an acyclic hydrazo compound; a colorless transparent liquid with a sharp organic amine odor. Two isomeric dimethylhydrazines are known: symmetrical dimethylhydrazine, CH3NH―NHCH3, and unsymmetrical dimethylhydrazine, (CH3)2N―NH2.

Unsymmetrical dimethylhydrazine is of practical significance. Boiling point, 63°C; melting point, −57.2°C; density, 0.795 g/cm3 (20°C); heat of formation ΔH0298 (liquid), 47.4 ± 3 kilojoules per mole, or 11.3 ± 0.7 kilocalories per mole. It is soluble in water and organic solvents (for example, alcohol); it is hygroscopic; and its aqueous solutions exhibit weakly alkaline reactions. In air, (CH3)2N—NH2 oxidizes slowly and ignites spontaneously at 270° C. Mixtures of its vapor with air are explosive within the limits of 2-99 percent (by volume). It is not sensitive to impact and detonation and is highly poisonous. Dimethylhydrazine is produced by the nitrosation of dimethylamine followed by the reduction of the dimethylnitrosamine with hydrogen

or by the reaction of dimethylamine with chloramine

(CH3)2 + NH2Cl + NaOH → (CH3)2NNH2 + NaCl + H2O

Unsymmetrical dimethylhydrazine is used as the combustible component of liquid rocket fuel.


Motornye i raketnye topliva, 4th ed. Edited by K. K. Papok and E.G. Semenido. Moscow, 1962.
Sarner, S. Khimiia raketnykh topliv. Moscow, 1969. (Translated from English.)


References in periodicals archive ?
The DMH solution used for injection was prepared with 400 mg of DMH (symmetrical dimethylhydrazine dihydrochloride, Sigma Chem.
Mucous secretion in rat colonic mucosa during carcinogenesis induced by dimethylhydrazine.
1987) The influence of physical activity in 1,2 dimethylhydrazine induced colon carcinogenesis in the rat.
The experimental diets continued for 24 days after which 21 rats/ diet were injected with dimethylhydrazine (DMH) (25 mg/kg body weight) dissolved in saline with 1 mmol/L EDTA, adjusted to pH 7.
Arch continues to produce ultra pure hydrazine(TM), anhydrous hydrazine (AH, monomethyl hydrazine (MMH) and unsymmetrical dimethylhydrazine (UDMH) for both commercial and military applications at its Lake Charles Raschig facility.
In another study, mice were given dimethylhydrazine, a carcinogen shown to specifically induce tumors in the colon.