Hydrazine

For the class of antidepressants, see hydrazine (antidepressant).
Not to be confused with hydralazine or hydroxyzine.

Hydrazine
Skeletal formula of hydrazine with all explicit hydrogens added
Skeletal formula of hydrazine with all explicit hydrogens added
Spacefill model of hydrazine
Spacefill model of hydrazine
Stereo, skeletal formula of hydrazine with all explicit hydrogens added
Stereo, skeletal formula of hydrazine with all explicit hydrogens added
Ball and stick model of hydrazine
Ball and stick model of hydrazine

Anhydrous hydrazine
Names
IUPAC name
Hydrazine[2]
Systematic IUPAC name
Diazane[2]
Other names
Diamine[1]
Tetrahydridodinitrogen(N-N)
Diamidogen
Identifiers
3D model (JSmol)
3DMet
878137
ChEBI
ChEMBL
ChemSpider
ECHA InfoCard 100.005.560 Edit this at Wikidata
EC Number
  • 206-114-9
190
KEGG
MeSH Hydrazine
RTECS number
  • MU7175000
UNII
UN number 2029
  • InChI=1S/H4N2/c1-2/h1-2H2 checkY
    Key: OAKJQQAXSVQMHS-UHFFFAOYSA-N checkY
  • InChI=1/H4N2/c1-2/h1-2H2
    Key: OAKJQQAXSVQMHS-UHFFFAOYAZ
  • NN
Properties
N2H4
Molar mass 32.0452 g/mol
Appearance Colorless, fuming, oily liquid[3]
Odor Ammonia-like[3]
Density 1.021 g/cm3
Melting point 2 °C; 35 °F; 275 K
Boiling point 114 °C; 237 °F; 387 K
Miscible[3]
log P 0.67
Vapor pressure 1 kPa (at 30.7 °C)
Acidity (pKa) 8.10 ([N2H5]+)[4]
Basicity (pKb) 5.90
Conjugate acid Hydrazinium
1.46044 (at 22 °C)
Viscosity 0.876 cP
Structure
Triangular pyramidal at N
1.85 D[5]
Thermochemistry
121.52 J/(K·mol)
50.63 kJ/mol
Hazards
GHS labelling:
GHS02: Flammable GHS05: Corrosive GHS06: Toxic GHS08: Health hazard GHS09: Environmental hazard
Danger
H226, H301, H311, H314, H317, H331, H350, H410
P201, P261, P273, P280, P301+P310, P305+P351+P338
NFPA 704 (fire diamond)
NFPA 704 four-colored diamondHealth 4: Very short exposure could cause death or major residual injury. E.g. VX gasFlammability 4: Will rapidly or completely vaporize at normal atmospheric pressure and temperature, or is readily dispersed in air and will burn readily. Flash point below 23 °C (73 °F). E.g. propaneInstability 3: Capable of detonation or explosive decomposition but requires a strong initiating source, must be heated under confinement before initiation, reacts explosively with water, or will detonate if severely shocked. E.g. hydrogen peroxideSpecial hazards (white): no code
4
4
3
Flash point 52 °C (126 °F; 325 K)
24 to 270 °C (75 to 518 °F; 297 to 543 K)
Explosive limits 1.8–100%
Lethal dose or concentration (LD, LC):
59–60 mg/kg (oral in rats, mice)[6]
260 ppm (rat, 4 h)
630 ppm (rat, 1 h)
570 ppm (rat, 4 h)
252 ppm (mouse, 4 h)[7]
NIOSH (US health exposure limits):
PEL (Permissible)
 TWA 1 ppm (1.3 mg/m3) [skin][3]
REL (Recommended)
 Ca C 0.03 ppm (0.04 mg/m3) [2-hour][3]
IDLH (Immediate danger)
 Ca [50 ppm][3]
Safety data sheet (SDS) ICSC 0281
Related compounds
Other anions
 Tetrafluorohydrazine
Hydrogen peroxide
Diphosphane
Diphosphorus tetraiodide
Other cations
 Organic hydrazines
Related Binary azanes
 Ammonia
Triazane
Related compounds
 Diazene
Triazene
Tetrazene
Diphosphene
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
☒N verify (what is checkY☒N ?)

Hydrazine is an inorganic compound with the chemical formula N2H4. It is a simple pnictogen hydride, and is a colourless flammable liquid with an ammonia-like odour. Hydrazine is highly hazardous unless handled in solution as, for example, hydrazine hydrate (N2H4·xH2O).

Hydrazine is mainly used as a foaming agent in preparing polymer foams, but applications also include its uses as a precursor to pharmaceuticals and agrochemicals, as well as a long-term storable propellant for in-space spacecraft propulsion. Additionally, hydrazine is used in various rocket fuels and to prepare the gas precursors used in air bags. Hydrazine is used within both nuclear and conventional electrical power plant steam cycles as an oxygen scavenger to control concentrations of dissolved oxygen in an effort to reduce corrosion.[8] As of 2000, approximately 120,000 tons of hydrazine hydrate (corresponding to a 64% solution of hydrazine in water by weight) were manufactured worldwide per year.[9]

Hydrazines are a class of organic substances derived by replacing one or more hydrogen atoms in hydrazine by an organic group.[9]

  1. ^ "NIOSH Guide—Hydrazine". Centers for Disease Control. Retrieved 16 Aug 2012.
  2. ^ a b "hydrazine—PubChem Public Chemical Database". The PubChem Project. USA: National Center for Biotechnology Information.
  3. ^ a b c d e f NIOSH Pocket Guide to Chemical Hazards. "#0329". National Institute for Occupational Safety and Health (NIOSH).
  4. ^ Hall HK, et al. (1957). "Correlation of the Base Strengths of Amines1". J. Am. Chem. Soc. 79 (20): 5441. doi:10.1021/ja01577a030.
  5. ^ Greenwood NN, Earnshaw A (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. ISBN 978-0-08-037941-8.
  6. ^ Martel B, Cassidy K, et al. (2004). Chemical Risk Analysis: A Practical Handbook. Amsterdam: Butterworth–Heinemann. p. 361. ISBN 978-1-903996-65-2. OCLC 939257974.
  7. ^ "Hydrazine". Immediately Dangerous to Life or Health Concentrations (IDLH). National Institute for Occupational Safety and Health (NIOSH).
  8. ^ Tsubakizaki S, Takada M, Gotou H, Mawatari K, Ishihara N, Kai R (2009). "Alternatives to Hydrazine in Water Treatment at Thermal Power Plants" (PDF). Mitsubishi Heavy Industries Technical Review. 6 (2): 43–47.
  9. ^ a b Cite error: The named reference Ullmann was invoked but never defined (see the help page).