Names | |
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Preferred IUPAC name Methylhydrazine [1] | |
Other names Methyldiazane, monomethyl hydrazine | |
Identifiers | |
3D model (JSmol) | |
635645 | |
ChEMBL | |
ChemSpider | |
ECHA InfoCard | 100.000.429 |
EC Number |
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MeSH | Monomethylhydrazine |
PubChem CID | |
RTECS number |
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UNII | |
UN number | 1244 |
CompTox Dashboard (EPA) | |
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Properties | |
CH6N2 | |
Molar mass | 46.073 g·mol−1 |
Appearance | Fuming, colourless liquid |
Odor | Fish-like [2] |
Density | 875 mg/mL (at 20 °C) |
Melting point | −52 °C (−62 °F; 221 K) |
Boiling point | 87.50 °C; 189.50 °F; 360.65 K |
Miscible [3] | |
log P | −1.318 |
Vapor pressure | 5.00 kPa (at 20 °C) |
Refractive index (nD) | 1.4325 |
Thermochemistry | |
Heat capacity (C) | 134.93 J/(K·mol) |
Std molar entropy (S⦵298) | 165.94 J/(K·mol) |
Std enthalpy of formation (ΔfH⦵298) | 54.14 kJ/mol |
Std enthalpy of combustion (ΔcH⦵298) | −1305.8 to −1304.6 kJ/mol |
Hazards | |
Occupational safety and health (OHS/OSH): | |
Main hazards | highly toxic and reactive liquid |
GHS labelling: | |
Danger | |
H225, H300, H301, H311, H314, H330, H351, H411 | |
P210, P260, P273, P280, P284 | |
NFPA 704 (fire diamond) | |
Flash point | −8 °C; 17 °F; 265 K [3] |
196 °C (385 °F; 469 K) | |
Explosive limits | 2.5–92% [3] |
Lethal dose or concentration (LD, LC): | |
LD50 (median dose) | 32 mg/kg (oral, rat) |
LC50 (median concentration) |
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NIOSH (US health exposure limits): | |
PEL (Permissible) | C 0.2 ppm (0.35 mg/m3) [skin] [3] |
REL (Recommended) | Ca C 0.04 ppm (0.08 mg/m3) [2-hr] [3] |
IDLH (Immediate danger) | Ca [20 ppm] [3] |
Safety data sheet (SDS) | inchem.org |
Related compounds | |
Related compounds | |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). |
Monomethylhydrazine (mono-methyl hydrazine, MMH) is a highly toxic, volatile hydrazine derivative with the chemical formula CH6N2. It is used as a rocket propellant in bipropellant rocket engines because it is hypergolic with various oxidizers such as nitrogen tetroxide (N2O4) and nitric acid (HNO3). As a propellant, it is described in specification MIL-PRF-27404. [5]
MMH is a hydrazine derivative that was once used in the orbital maneuvering system (OMS) and reaction control system (RCS) engines of NASA's Space Shuttle, which used MMH and MON-3 (a mixture of nitrogen tetroxide with approximately 3% nitric oxide). This chemical is toxic and carcinogenic, [6] but it is easily stored in orbit, providing moderate performance for very low fuel tank system weight. MMH and its chemical relative unsymmetrical dimethylhydrazine (UDMH) have a key advantage that they are stable enough to be used in regeneratively cooled rocket engines. The European Space Agency (ESA) has attempted to seek new options in terms of bipropellant rocket combinations to avoid using deadly chemicals such as MMH and its relatives. [7]
MMH is believed to be the main cause of the toxicity of mushrooms of genus Gyromitra , especially the false morel ( Gyromitra esculenta ). In these cases, MMH is formed by the hydrolysis of gyromitrin. [8]
Monomethylhydrazine is considered to be a possible occupational carcinogen, [9] and the occupational exposure limits to MMH are set at protective levels to account for the possible carcinogenicity. [10]
A known use of MMH is in the synthesis of suritozole. [11]
MMH is also assumed to be the active methylating agent in the drug Temozolomide. [12]
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 toxic unless handled in solution as, for example, hydrazine hydrate.
A hypergolic propellant is a rocket propellant combination used in a rocket engine, whose components spontaneously ignite when they come into contact with each other.
Unsymmetrical dimethylhydrazine (UDMH; 1,1-dimethylhydrazine, heptyl or codenamed Geptil) is a chemical compound with the formula H2NN(CH3)2 that is used as a rocket propellant. It is a colorless liquid, with a sharp, fishy, ammonia-like smell typical for organic amines. Samples turn yellowish on exposure to air and absorb oxygen and carbon dioxide. It is miscible with water, ethanol, and kerosene. In concentration between 2.5% and 95% in air, its vapors are flammable. It is not sensitive to shock. Symmetrical dimethylhydrazine (1,2-dimethylhydrazine) is also known but is not as useful. UDMH can be oxidized in air to form many different substances, including toxic ones.
Monopropellants are propellants consisting of chemicals that release energy through exothermic chemical decomposition. The molecular bond energy of the monopropellant is released usually through use of a catalyst. This can be contrasted with bipropellants that release energy through the chemical reaction between an oxidizer and a fuel. While stable under defined storage conditions, monopropellants decompose very rapidly under certain other conditions to produce a large volume of its own energetic (hot) gases for the performance of mechanical work. Although solid deflagrants such as nitrocellulose, the most commonly used propellant in firearms, could be thought of as monopropellants, the term is usually reserved for liquids in engineering literature.
Dinitrogen tetroxide, commonly referred to as nitrogen tetroxide (NTO), and occasionally (usually among ex-USSR/Russia rocket engineers) as amyl, is the chemical compound N2O4. It is a useful reagent in chemical synthesis. It forms an equilibrium mixture with nitrogen dioxide. Its molar mass is 92.011 g/mol.
Gyromitra esculenta is an ascomycete fungus from the genus Gyromitra, widely distributed across Europe and North America. It normally fruits in sandy soils under coniferous trees in spring and early summer. The fruiting body, or mushroom, is an irregular brain-shaped cap dark brown in colour that can reach 10 centimetres high and 15 cm (6 in) wide, perched on a stout white stipe up to 6 cm high.
Gyromitrin is a toxin and carcinogen present in several members of the fungal genus Gyromitra, like G. esculenta. Its formula is C4H8N2O. It is unstable and is easily hydrolyzed to the toxic compound monomethylhydrazine CH3NHNH2. Monomethylhydrazine acts on the central nervous system and interferes with the normal use and function of vitamin B6. Poisoning results in nausea, stomach cramps, and diarrhea, while severe poisoning can result in convulsions, jaundice, or even coma or death. Exposure to monomethylhydrazine has been shown to be carcinogenic in small mammals.
Aerozine 50 is a 50:50 mix by weight of hydrazine and unsymmetrical dimethylhydrazine (UDMH), originally developed in the late 1950s by Aerojet General Corporation as a storable, high-energy, hypergolic fuel for the Titan II ICBM rocket engines. Aerozine continues in wide use as a rocket fuel, typically with dinitrogen tetroxide as the oxidizer, with which it is hypergolic. Aerozine 50 is more stable than hydrazine alone, and has a higher density and boiling point than UDMH alone.
Propyne (methylacetylene) is an alkyne with the chemical formula CH3C≡CH. It is a component of MAPD gas—along with its isomer propadiene (allene), which was commonly used in gas welding. Unlike acetylene, propyne can be safely condensed.
The highest specific impulse chemical rockets use liquid propellants. They can consist of a single chemical or a mix of two chemicals, called bipropellants. Bipropellants can further be divided into two categories; hypergolic propellants, which ignite when the fuel and oxidizer make contact, and non-hypergolic propellants which require an ignition source.
Pentaborane(9) is an inorganic compound with the formula B5H9. It is one of the most common boron hydride clusters, although it is a highly reactive compound. Because of its high reactivity toward oxygen, it was once evaluated as rocket or jet fuel. Like many of the smaller boron hydrides, pentaborane is colourless, diamagnetic, and volatile. It is related to pentaborane(11).
Toluene diisocyanate (TDI) is an organic compound with the formula CH3C6H3(NCO)2. Two of the six possible isomers are commercially important: 2,4-TDI (CAS: 584-84-9) and 2,6-TDI (CAS: 91-08-7). 2,4-TDI is produced in the pure state, but TDI is often marketed as 80/20 and 65/35 mixtures of the 2,4 and 2,6 isomers respectively. It is produced on a large scale, accounting for 34.1% of the global isocyanate market in 2000, second only to MDI. Approximately 1.4 billion kilograms were produced in 2000. All isomers of TDI are colorless, although commercial samples can appear yellow.
Aziridine is an organic compound consisting of the three-membered heterocycle C2H5N. It is a colorless, toxic, volatile liquid that is of significant practical interest. Aziridine was discovered in 1888 by the chemist Siegmund Gabriel. Its derivatives, also referred to as aziridines, are of broader interest in medicinal chemistry.
2,4-Dinitrotoluene (DNT) or dinitro is an organic compound with the formula C7H6N2O4. This pale yellow crystalline solid is well known as a precursor to trinitrotoluene (TNT) but is mainly produced as a precursor to toluene diisocyanate.
Perchloryl fluoride is a reactive gas with the chemical formula ClO
3F. It has a characteristic sweet odor that resembles gasoline and kerosene. It is toxic and is a powerful oxidizing and fluorinating agent. It is the acid fluoride of perchloric acid.
Tetranitromethane or TNM is an organic oxidizer with chemical formula C(NO2)4. Its chemical structure consists of four nitro groups attached to one carbon atom. In 1857 it was first synthesised by the reaction of sodium cyanoacetamide with nitric acid.
The name false morel is given to several species of mushroom which bear a resemblance to the highly regarded true morels of the genus Morchella. Like Morchella, false morels are members of the Pezizales, but within that group represent several unrelated taxa scattered through the families Morchellaceae, Discinaceae, and Helvellaceae, with the epithet "false morel" most often ascribed to members of the genus Gyromitra.
2-Dimethylaminoethylazide (DMAZ) is a liquid rocket fuel being investigated for use as a spacecraft propellent to replace the toxic, carcinogenic monomethylhydrazine. It is a member of the competitive impulse non-carcinogenic hypergol (CINCH) family which were assessed as a replacement for hydrazine-derived propellants. DMAZ was also found to be sensitive to impact, direct flame, shock wave, heat in confined space, and electrostatic discharge.
1-Nitropropane (1-NP) is a solvent. It is a colorless liquid, an isomer of 2-nitropropane (2-NP), and classified as a nitro compound.
The Hispasat 1D, since 2016 called Hispasat 30W-4 is a Spanish communications satellite launched in 2002 operated by Hispasat. Together with the Hispasat 1C it formed a constellation in order to strengthen communication ties between the American continent and the Iberian Peninsula for both governmental and private uses.
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