Unsymmetrical dimethylhydrazine

Unsymmetrical dimethylhydrazine
Skeletal formula of unsymmetrical dimethylhydrazine with some implicit hydrogens shown
Skeletal formula of unsymmetrical dimethylhydrazine with some implicit hydrogens shown
Ball and stick model of unsymmetrical dimethylhydrazine
Ball and stick model of unsymmetrical dimethylhydrazine
Names
Preferred IUPAC name
1,1-Dimethylhydrazine[1]
Other names
Dimazine
1,1-Dimethyldiazane
Identifiers
3D model (JSmol)
605261
ChEBI
ChemSpider
ECHA InfoCard 100.000.287 Edit this at Wikidata
EC Number
  • 200-316-0
KEGG
MeSH dimazine
RTECS number
  • MV2450000
UNII
UN number 1163
  • InChI=1S/C2H8N2/c1-4(2)3/h3H2,1-2H3 ☒N
    Key: RHUYHJGZWVXEHW-UHFFFAOYSA-N ☒N
  • CN(C)N
Properties
H2NN(CH3)2
Appearance Colorless liquid
Odor Ammoniacal, fishy
Density 791 kg m−3 (at 22 °C)
Melting point −57 °C; −71 °F; 216 K
Boiling point 64.0 °C; 147.1 °F; 337.1 K
Miscible[2]
Vapor pressure 13.7 kPa (at 20 °C)
1.4075
Thermochemistry
164.05 J K−1 mol−1
200.25 J K−1 mol−1
48.3 kJ mol−1
−1982.3 – −1975.1 kJ mol−1
Hazards
Occupational safety and health (OHS/OSH):
Main hazards
 Carcinogen, spontaneously ignites on contact with oxidizers
GHS labelling:
GHS02: Flammable GHS05: Corrosive GHS06: Toxic GHS08: Health hazard GHS09: Environmental hazard
Danger
H225, H301, H314, H331, H350, H411
P210, P261, P273, P280, P301+P310
NFPA 704 (fire diamond)
NFPA 704 four-colored diamondHealth 4: Very short exposure could cause death or major residual injury. E.g. VX gasFlammability 3: Liquids and solids that can be ignited under almost all ambient temperature conditions. Flash point between 23 and 38 °C (73 and 100 °F). E.g. gasolineInstability 1: Normally stable, but can become unstable at elevated temperatures and pressures. E.g. calciumSpecial hazards (white): no code
4
3
1
Flash point −10 °C (14 °F; 263 K)
248 °C (478 °F; 521 K)
Explosive limits 2–95%
Lethal dose or concentration (LD, LC):
  • 122 mg kg−1 (oral, rat)
  • 1.06 g kg−1 (dermal, rabbit)
  • 252 ppm (rat, 4 hr)
  • 172 ppm (mouse, 4 hr)
  • 392 ppm (hamster, 4 hr)
  • 3580 ppm (dog, 15 min)
  • 1410 ppm (rat, 1 hr)
  • 981 ppm (dog, 1 hr)[3]
NIOSH (US health exposure limits):
PEL (Permissible)
 TWA 0.5 ppm (1 mg/m3) [skin][2]
REL (Recommended)
 Ca C 0.06 ppm (0.15 mg/m3) [2 hr][2]
IDLH (Immediate danger)
 Ca [15 ppm][2]
Related compounds
Related compounds
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Unsymmetrical dimethylhydrazine (abbreviated as UDMH; also known as 1,1-dimethylhydrazine, heptyl or Geptil) is a chemical compound with the formula H2NN(CH3)2 that is primarily used as a rocket propellant.[4] At room temperature, UDMH is a colorless liquid, with a sharp, fishy, ammonia-like smell typical of organic amines. Samples turn yellowish on exposure to air and absorb oxygen and carbon dioxide. It is miscible with water, ethanol, and kerosene. At concentrations between 2.5% and 95% in air, its vapors are flammable. It is not sensitive to shock.

Symmetrical dimethylhydrazine (1,2-dimethylhydrazine) also exists, but it is not as useful.[5] UDMH can be oxidized in air to form many different substances, including toxic ones.[6][7][8]

  1. ^ "dimazine – Compound Summary". PubChem Compound. USA: National Center for Biotechnology Information. 26 March 2005. Identification. Retrieved 21 February 2012.
  2. ^ a b c d NIOSH Pocket Guide to Chemical Hazards. "#0227". National Institute for Occupational Safety and Health (NIOSH).
  3. ^ "1,1-Dimethylhydrazine". Immediately Dangerous to Life or Health Concentrations (IDLH). National Institute for Occupational Safety and Health (NIOSH).
  4. ^ Semenkov, Ivan; Koroleva, Tatyana (1 December 2022). "Review on the environmental impact of emissions from space launches: a case study for areas affected by the Russian space programme". Environmental Science and Pollution Research. 29 (60): 89807–89822. Bibcode:2022ESPR...2989807S. doi:10.1007/s11356-022-23888-8. ISSN 1614-7499. PMID 36346528. S2CID 253396676.
  5. ^ Cite error: The named reference Ullmann was invoked but never defined (see the help page).
  6. ^ Aleksey Milyushkin, Anastasia Karnaeva (2023). "Unsymmetrical dimethylhydrazine transformation products: A review". Science of the Total Environment. 891: 164367. Bibcode:2023ScTEn.89164367M. doi:10.1016/j.scitotenv.2023.164367. PMID 37236454. S2CID 258899003.
  7. ^ Ul'yanovskii, Nikolay V.; Lakhmanov, Dmitry E.; Pikovskoi, Ilya I.; Falev, Danil I.; Popov, Mark S.; Kozhevnikov, Alexander Yu.; Kosyakov, Dmitry S. (15 July 2020). "Migration and transformation of 1,1-dimethylhydrazine in peat bog soil of rocket stage fall site in Russian North". Science of the Total Environment. 726: 138483. Bibcode:2020ScTEn.72638483U. doi:10.1016/j.scitotenv.2020.138483. ISSN 0048-9697. PMID 32315849. S2CID 216073493.
  8. ^ Koroleva, T. V.; Semenkov, I. N.; Lednev, S. A.; Soldatova, O. S. (1 February 2023). "Unsymmetrical Dimethylhydrazine (UDMH) and Its Transformation Products in Soils: A Review of the Sources, Detection, Behavior, Toxicity, and Remediation of Polluted Territories". Eurasian Soil Science. 56 (2): 210–225. Bibcode:2023EurSS..56..210K. doi:10.1134/S1064229322602001. ISSN 1556-195X. S2CID 257903133.