Unsymmetrical dimethylhydrazine

Unsymmetrical dimethylhydrazine
Names
	Preferred IUPAC name 1,1-Dimethylhydrazine
	Other names Dimazine ; 1,1-Dimethyldiazane ;
Identifiers
CAS Number	57-14-7 ;
3D model (JSmol)	Interactive image;
Beilstein Reference	605261
ChEBI	CHEBI:18853 ;
ChemSpider	5756 ;
ECHA InfoCard	100.000.287
EC Number	200-316-0;
KEGG	C19233 ;
MeSH	dimazine
PubChem CID	5976;
RTECS number	MV2450000;
UNII	4WPQ90N53J ;
UN number	1163
CompTox Dashboard (EPA)	DTXSID1020516 ;
	InChI InChI=1S/C2H8N2/c1-4(2)3/h3H2,1-2H3 Key: RHUYHJGZWVXEHW-UHFFFAOYSA-N ;
	SMILES CN(C)N;
Properties
Chemical formula	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
Solubility in water	Miscible
Vapor pressure	13.7 kPa (at 20 °C)
Refractive index (nD)	1.4075
Thermochemistry
Heat capacity (C)	164.05 J K−1 mol−1
Std molar; entropy (S⦵298)	200.25 J K−1 mol−1
Std enthalpy of; formation (ΔfH⦵298)	48.3 kJ mol−1
Std enthalpy of; combustion (ΔcH⦵298)	−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:
Pictograms
Signal word	Danger
Hazard statements	H225, H301, H314, H331, H350, H411
Precautionary statements	P210, P261, P273, P280, P301+P310
NFPA 704 (fire diamond)	4 3 1
Flash point	−10 °C (14 °F; 263 K)
Autoignition; temperature	248 °C (478 °F; 521 K)
Explosive limits	2–95%
	Lethal dose or concentration (LD, LC):
LD50 (median dose)	122 mg kg−1 (oral, rat); 1.06 g kg−1 (dermal, rabbit);
LC50 (median concentration)	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);
	NIOSH (US health exposure limits):
PEL (Permissible)	TWA 0.5 ppm (1 mg/m3) [skin]
REL (Recommended)	Ca C 0.06 ppm (0.15 mg/m3) [2 hr]
IDLH (Immediate danger)	Ca [15 ppm]
Related compounds
Related compounds	Dimethylamine; Hydrazine; Symmetrical dimethylhydrazine;
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). verify (what is ?) Infobox references

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]

^ "dimazine – Compound Summary". PubChem Compound. USA: National Center for Biotechnology Information. 26 March 2005. Identification. Retrieved 21 February 2012.
^ ^a ^b ^c ^d NIOSH Pocket Guide to Chemical Hazards. "#0227". National Institute for Occupational Safety and Health (NIOSH).
^ "1,1-Dimethylhydrazine". Immediately Dangerous to Life or Health Concentrations (IDLH). National Institute for Occupational Safety and Health (NIOSH).
^ 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.
^ Cite error: The named reference Ullmann was invoked but never defined (see the help page).
^ 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.{{cite journal}}: CS1 maint: article number as page number (link)
^ 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.{{cite journal}}: CS1 maint: article number as page number (link)
^ 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.

[1] "dimazine – Compound Summary". PubChem Compound. USA: National Center for Biotechnology Information. 26 March 2005. Identification. Retrieved 21 February 2012.

[PGCH-2] 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.

[Ullmann-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.{{cite journal}}: CS1 maint: article number as page number (link)

[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.{{cite journal}}: CS1 maint: article number as page number (link)

[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.

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