Editing Unsymmetrical dimethylhydrazine (section)

{{short description|Rocket fuel}}
{{Use dmy dates|date=March 2024}}
{{chembox
| Verifiedfields = changed
| Watchedfields  = changed
| verifiedrevid  = 450852466
| ImageFileL1    = 1,1-Dimethylhydrazin2.svg
| ImageFileL1_Ref = {{chemboximage|correct|??}}
| ImageSizeL1    = 100
| ImageNameL1    = Skeletal formula of unsymmetrical dimethylhydrazine with some implicit hydrogens shown
| ImageFileR1    = 1,1-dimethylhydrazine-3D-balls.png
| ImageFileR1_Ref = {{chemboximage|correct|??}}
| ImageSizeR1    = 100
| ImageNameR1    = Ball and stick model of unsymmetrical dimethylhydrazine
| PIN            = 1,1-Dimethylhydrazine<ref>{{cite web|title=dimazine – Compound Summary|url=https://pubchem.ncbi.nlm.nih.gov/summary/summary.cgi?cid=5976&loc=ec_rcs|work=PubChem Compound|publisher=National Center for Biotechnology Information|access-date=21 February 2012|location=USA|date=26 March 2005|at=Identification}}</ref>
| OtherNames     = Dimazine <br />
1,1-Dimethyldiazane <br>
| Section1       = {{Chembox Identifiers
| CASNo = 57-14-7
| CASNo_Ref = {{cascite|correct|CAS}}
| UNII_Ref = {{fdacite|correct|FDA}}
| UNII = 4WPQ90N53J
| PubChem = 5976
| ChemSpiderID = 5756
| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}
| EINECS = 200-316-0
| UNNumber = 1163
| KEGG = C19233
| KEGG_Ref = {{keggcite|correct|kegg}}
| MeSHName = dimazine
| ChEBI = 18853
| ChEBI_Ref = {{ebicite|correct|EBI}}
| RTECS = MV2450000
| Beilstein = 605261
| SMILES = CN(C)N
| StdInChI = 1S/C2H8N2/c1-4(2)3/h3H2,1-2H3
| StdInChI_Ref = {{stdinchicite|changed|chemspider}}
| StdInChIKey = RHUYHJGZWVXEHW-UHFFFAOYSA-N
| StdInChIKey_Ref = {{stdinchicite|changed|chemspider}}
}}
| Section2       = {{Chembox Properties
| Formula = H<sub>2</sub>NN(CH<sub>3</sub>)<sub>2</sub>
| Appearance = Colorless liquid
| Odor = Ammoniacal, fishy
| Density = 791{{nbsp}}kg{{nnbsp}}m<sup>−3</sup> (at 22{{nbsp}}°C)
| MeltingPtK = 216
| BoilingPtK = 337.1
| VaporPressure = 13.7{{nbsp}}kPa (at 20{{nbsp}}°C)
| RefractIndex = 1.4075
| Solubility = Miscible<ref name=PGCH />
}}
| Section3       = {{Chembox Thermochemistry
| DeltaHf = 48.3{{nbsp}}kJ{{nnbsp}}mol<sup>−1</sup>
| DeltaHc = −1982.3 – −1975.1{{nbsp}}kJ{{nnbsp}}mol<sup>−1</sup>
| Entropy = 200.25{{nbsp}}J{{nnbsp}}K<sup>−1</sup>{{nnbsp}}mol<sup>−1</sup>
| HeatCapacity = 164.05{{nbsp}}J{{nnbsp}}K<sup>−1</sup>{{nnbsp}}mol<sup>−1</sup>
}}
| Section4       = {{Chembox Hazards
| GHSPictograms = {{gHS flame}} {{gHS corrosion}} {{gHS skull and crossbones}} {{gHS health hazard}} {{gHS environment}}
| GHSSignalWord = '''DANGER'''
| HPhrases = {{h-phrases|225|301|314|331|350|411}}
| PPhrases = {{p-phrases|210|261|273|280|301+310}}
| NFPA-H = 4
| NFPA-F = 3
| NFPA-R = 1
| FlashPtC = −10
| AutoignitionPtC = 248
| ExploLimits = 2–95%
| LD50 = {{unbulleted list
 | 122{{nbsp}}mg kg<sup>−1</sup> <small>(oral, rat)</small>
 | 1.06{{nbsp}}g kg<sup>−1</sup> <small>(dermal, rabbit)</small>
 }}
| PEL = TWA 0.5{{nbsp}}ppm (1{{nbsp}}mg/m<sup>3</sup>) [skin]<ref name=PGCH>{{PGCH|0227}}</ref>
| IDLH = Ca [15{{nbsp}}ppm]<ref name=PGCH />
| REL = Ca C 0.06{{nbsp}}ppm (0.15{{nbsp}}mg/m<sup>3</sup>) [2{{nbsp}}hr]<ref name=PGCH />
| MainHazards = Carcinogen, spontaneously ignites on contact with oxidizers
| LC50 = {{ubl
 | 252{{nbsp}}ppm (rat, 4{{nbsp}}hr)
 | 172{{nbsp}}ppm (mouse, 4{{nbsp}}hr)
 | 392{{nbsp}}ppm (hamster, 4{{nbsp}}hr)
 | 3580{{nbsp}}ppm (dog, 15{{nbsp}}min)
 | 1410{{nbsp}}ppm (rat, 1{{nbsp}}hr)
 | 981{{nbsp}}ppm (dog, 1{{nbsp}}hr)<ref>{{IDLH|57147|1,1-Dimethylhydrazine}}</ref>
 }}
}}
| Section5       = {{Chembox Related
| OtherCompounds = {{unbulleted list
 | [[Dimethylamine]]
 | [[Hydrazine]]
 | [[Symmetrical dimethylhydrazine]]
 }}
}}
}}

'''Unsymmetrical dimethylhydrazine''' (abbreviated as '''UDMH'''; also known as '''1,1-dimethylhydrazine''', '''heptyl''' or '''Geptil''') is a [[chemical compound]] with the formula H<sub>2</sub>NN(CH<sub>3</sub>)<sub>2</sub> that is primarily used as a [[rocket propellant]].<ref>{{Cite journal |last1=Semenkov |first1=Ivan |last2=Koroleva |first2=Tatyana |date=1 December 2022 |title=Review on the environmental impact of emissions from space launches: a case study for areas affected by the Russian space programme |url=https://doi.org/10.1007/s11356-022-23888-8 |journal=Environmental Science and Pollution Research |language=en |volume=29 |issue=60 |pages=89807–89822 |doi=10.1007/s11356-022-23888-8 |pmid=36346528 |bibcode=2022ESPR...2989807S |s2cid=253396676 |issn=1614-7499|url-access=subscription }}</ref> At room temperature, UDMH is a colorless liquid, with a sharp, fishy, ammonia-like smell typical of organic [[amine]]s. Samples turn yellowish on exposure to air and absorb [[oxygen]] and [[carbon dioxide]]. It is [[Miscibility|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.<ref name="Ullmann" /> UDMH can be oxidized in air to form many different substances, including toxic ones.<ref>{{cite journal|title=Unsymmetrical dimethylhydrazine transformation products: A review
|author=Aleksey Milyushkin, Anastasia Karnaeva
|journal=Science of the Total Environment
|volume=891
|year=2023
|page=164367
|doi=10.1016/j.scitotenv.2023.164367
|pmid=37236454
|bibcode=2023ScTEn.89164367M
|s2cid=258899003
}}</ref><ref>{{Cite journal |last1=Ul'yanovskii |first1=Nikolay V. |last2=Lakhmanov |first2=Dmitry E. |last3=Pikovskoi |first3=Ilya I. |last4=Falev |first4=Danil I. |last5=Popov |first5=Mark S. |last6=Kozhevnikov |first6=Alexander Yu. |last7=Kosyakov |first7=Dmitry S. |date=15 July 2020 |title=Migration and transformation of 1,1-dimethylhydrazine in peat bog soil of rocket stage fall site in Russian North |url=https://www.sciencedirect.com/science/article/pii/S0048969720319963 |journal=Science of the Total Environment |volume=726 |pages=138483 |doi=10.1016/j.scitotenv.2020.138483 |pmid=32315849 |bibcode=2020ScTEn.72638483U |s2cid=216073493 |issn=0048-9697|url-access=subscription }}</ref><ref>{{Cite journal |last1=Koroleva |first1=T. V. |last2=Semenkov |first2=I. N. |last3=Lednev |first3=S. A. |last4=Soldatova |first4=O. S. |date=1 February 2023 |title=Unsymmetrical Dimethylhydrazine (UDMH) and Its Transformation Products in Soils: A Review of the Sources, Detection, Behavior, Toxicity, and Remediation of Polluted Territories |url=https://doi.org/10.1134/S1064229322602001 |journal=Eurasian Soil Science |language=en |volume=56 |issue=2 |pages=210–225 |doi=10.1134/S1064229322602001 |bibcode=2023EurSS..56..210K |s2cid=257903133 |issn=1556-195X|url-access=subscription }}</ref>