4770. Hydrazine

Nomenclature

CAS number: 302-01-2
Hydrazine anhydrous.
H4N2; mol wt 32.05.
H 12.58%, N 87.41%.
H2NNH2.

Description and references

Prepn from hydrazine hydrate: Sisler et al., J. Am. Chem. Soc. 76, 3914 (1954); Schenk in Handbook of Preparative Inorganic Chemistry vol. 1, G. Brauer, Ed. (Academic Press, New York, 1963) pp 469-472. Toxicity data: Witkin, Arch. Ind. Health 13, 34 (1956). Toxicology study: Back, Thomas, Annu. Rev. Pharmacol. 10, 395 (1970). Review of carcinogenic risk: IARC Monographs 4, 127-136 (1974); of toxicology: R. von Burg, T. Stout, J. Appl. Toxicol. 11, 447-450 (1991); and human exposure: Toxicological Profile for Hydrazines (PB98-101025, 1997) 224 pp. Books: L. F. Audrieth, B. A. Ogg, The Chemistry of Hydrazine (Wiley, New York, 1951); C. C. Clark, Hydrazine (Mathieson Chem., Baltimore, 1953). Reviews: Troyan, Ind. Eng. Chem. 45, 2608-2612 (1953); Zimmer, Chem. Ztg. 79, 599-605 (1955); Hudson et al., “Hydrazine” in Mellor's vol. VIII, suppl. II, Nitrogen (Part 2), 69-114 (1967); Jones in Comprehensive Inorganic Chemistry vol. 2, J. C. Bailar, Jr. et al., Eds. (Pergamon Press, Oxford, 1973) p 250-265; H. W. Schiessl in Kirk-Othmer Encyclopedia of Chemical Technology vol. 13 (John Wiley & Sons, New York, 4th ed., 1995) pp 560-606.

Properties

Colorless oily liq, fuming in air. Corrosive, flammable, poisonous. Penetrating odor resembling that of ammonia. Burns with violet flame. Explodes during distn if traces of air are present, also affected by uv and metal ion catalysts. Can be stored for years if sealed in glass and kept in a cool, dark place. Flash and fire pt 126°F (52°C). Contracts on freezing. d45 1.146; d40 1.0253; d42 1.024; d415 1.011; d425 1.0036; d435 0.9955. One gallon of commercial product weighs 8.38 lbs. mp 2.0°. bp760 113.5°; bp71 56°; bp5 atm 170°; bp10 atm 200°; bp20 atm 236°. nD22.3 1.46979; nD35 1.46444. Dipole moment 1.83-1.90. Dielectric constant (25°): 51.7. Latent heat of fusion (mp): 3.025 kcal/mole; latent heat of vaporization (bp): 9760 kcal/mole (calc). Crit temp 380°; crit pressure 14 atm. Diacidic base. pK1 (25°): ≈6.05. Forms salts with inorganic acids. Highly polar solvent. Powerful reducing agent. Dissolves many inorganic substances. Misc with water, methyl, ethyl, propyl, isobutyl alcohols. Forms an azeotropic mixture with water, bp760 120.3°, which contains 55 mole-% (68.5 weight-%) N2H4. LD50 in mice (mg/kg): 57 i.v.; 59 orally (Witkin).

Derivative

Dihydrochloride.

Nomenclature

CAS number: 5341-61-7
H4N2.2HCl; mol wt 104.97.
H 5.76%, N 26.69%, Cl 67.55%.

Properties

White crystalline powder, mp 198°. d 1.42. Freely sol in water, slightly in alcohol.

Caution

Potential symptoms of overexposure to hydrazine are irritation of eyes, skin, nose and throat; temporary blindness; dizziness, nausea; dermatitis; burns skin and eyes. See NIOSH Pocket Guide to Chemical Hazards (DHHS/NIOSH 97-140, 1997) p 166. See also Patty's Industrial Hygiene and Toxicology vol. 2E, G. D. Clayton, F. E. Clayton, Eds. (John Wiley & Sons, Inc., New York, 4th ed., 1994) pp 3435-3441. Hydrazine is reasonably anticipated to be a human carcinogen: Report on Carcinogens, Eleventh Edition (PB2005-104914, 2004) p III-145.

Use

Chemical intermediate in manuf of agricultural chemicals, spandex fibers and antioxidants. Reducing agent; organic hydrazine derivs; rocket fuel. Dihydrochloride as chlorine scavenger for HCl gas streams.