Hydrazine

For the antidepressant, see Hydrazine (antidepressant).
Hydrazine

Hydrazine hydrate
Names
Systematic IUPAC name
Hydrazine[1]
Other names
Diamine[2]
Diazane[1]
Identifiers
3DMet B00770
878137
302-01-2 Yes
ChEBI CHEBI:15571 Yes
ChEMBL ChEMBL1237174 
ChemSpider 8960 Yes
EC number 206-114-9
190
Jmol-3D images Image
KEGG C05361 Yes
MeSH Hydrazine
PubChem 9321
RTECS number MU7175000
UNII 27RFH0GB4R Yes
UN number 2029
Properties
N
2H
4
Molar mass 32.0452 g mol−1
Appearance Colourless, fuming, oily liquid[3]
Odor ammonia-like[3]
Density 1.021 g cm−3
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 kP (at 30.7 °C)
Acidity (pKa) 8.10[4]
Basicity (pKb) 5.90
1.46044 (at 22 °C)
Viscosity 0.876 cP
Structure
Molecular shape Triangular pyramidal at N
Dipole moment 1.85 D[5]
Thermochemistry
121.52 J K−1 mol−1
Std enthalpy of
formation (ΔfHo298)
 50.63 kJ mol−1
Hazards
MSDS ICSC 0281
GHS pictograms
GHS signal word DANGER
H226, H301, H311, H314, H317, H331, H350, H410
P201, P261, P273, P280, P301+310, P305+351+338
EU Index 007-008-00-3
EU classification T+ N [6]
R-phrases R45, R10, R23/24/25, R34, R43, R50/53
S-phrases S53, S45, S60, S61
NFPA 704
Flammability code 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., propane Health code 4: Very short exposure could cause death or major residual injury. E.g., VX gas Reactivity code 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., fluorine Special hazards (white): no codeNFPA 704 four-colored diamond
4
4
3
Flash point 52 °C (126 °F; 325 K)
Explosive limits 1.8–99.99%
59–60 mg/kg (oral in rats, mice)[7]
US health exposure limits (NIOSH):
TWA 1 ppm (1.3 mg/m3) [skin][3]
Ca C 0.03 ppm (0.04 mg/m3) [2-hour][3]
Ca [50 ppm][3]
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 noted otherwise, data is given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
  verify (what is: Yes/?)
Infobox references

Hydrazine (systematically named diazane or tetrahydridodinitrogen(N—N)) is an inorganic compound with the chemical formula H
2NNH
2 (also written N
2H
4). It is a colourless flammable liquid with an ammonia-like odor. Hydrazine is highly toxic and dangerously unstable unless handled in solution. 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.[8] Hydrazine is mainly used as a foaming agent in preparing polymer foams, but significant applications also include its uses as a precursor to polymerization catalysts and pharmaceuticals. 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.

Molecular structure and properties

Hydrazine forms a monohydrate that is denser (1.032 g/cm3) than the anhydrous material.

Hydrazine can arise via coupling a pair of ammonia molecules by removal of one hydrogen per molecule. Each H2N-N subunit is pyramidal in shape. The N-N single bond distance is 1.45 Å (145 pm), and the molecule adopts a gauche conformation.[9] The rotational barrier is twice that of ethane. These structural properties resemble those of gaseous hydrogen peroxide, which adopts a "skewed" anticlinal conformation, and also experiences a strong rotational barrier.

Hydrazine has basic (alkali) chemical properties comparable to those of ammonia:

N2H4 + H2O → [N2H5]+ + OH−

with the values:[10]

Kb = 1.3 x 10−6
pKa = 8.1

(for ammonia Kb = 1.78 x 10−5)

Hydrazine is difficult to diprotonate:[11]

[N2H5]+ + H2O → [N2H6]2+ + OH− Kb = 8.4 x 10−16

The heat of combustion of hydrazine in oxygen (air) is 1.941 x 107 J/kg (9345 BTU/lb).[12]

Synthesis and production

Different routes have been developed over the years:[8] the key step is the creation of the nitrogen-nitrogen single bond. In the Olin Raschig process, chlorine-based oxidants oxidizes ammonia without the presence of ketone. In the Peroxide process, peroxide oxidant oxidizes ammonia in the presence of ketone. Instead of carbon-nitrogen double bond in imine, urea provides amine groups bonded to carbonyl for oxidation .

Oxidation by chloroamine from hypochlorite on ammonia

Hydrazine is produced in the Olin Raschig process from sodium hypochlorite (the active ingredient in many bleaches) and ammonia, a process announced in 1907. This method relies on the reaction of chloramine with ammonia to create the nitrogen-nitrogen single bond:[13]

NH2Cl + NH3 → H2N-NH2 + HCl

Oxidation of urea by hypochlorite

Related to the Rasching process, urea can be oxidized instead of ammonia. Again sodium hypochlorite serves as the oxidant. The net reaction is shown:[14]

(H2N)2C=O + NaOCl + 2 NaOH → N2H4 + H2O + NaCl + Na2CO3

The process generates significant byproducts and is mainly practiced in Asia.[8]

Oxidation by chloroamine from hypochlorite on ammonia in presence of acetone

The Bayer Ketazine Process is the predecessor to the Peroxide process. It employs sodium hypochlorite as oxidant instead of hydrogen peroxide. Like all hypochlorite-based routes, this method suffers from the fact that it produces an equivalent of salt for each equivalent of hydrazine.[8]

Oxidation by oxaziridine from peroxide on ammonia

Hydrazine can be synthesized from ammonia and hydrogen peroxide in the Peroxide process (sometimes called Pechiney-Ugine-Kuhlmann process, the Atofina–PCUK cycle, or ketazine process).[8] The net reaction is shown: The net conversion follows:[15]

2 NH3 + H2O2 → H2N-NH2 + 2 H2O

In this route, hydrazine is produced in several steps from ammonia, hydrogen peroxide, and a ketone such as acetone or methylethyl ketone. The ketone and ammonia first condense to give the imine, which is oxidised by hydrogen peroxide to the oxaziridine, a three-membered ring containing carbon, oxygen, and nitrogen. Next, the oxaziridine gives the hydrazone by treatment with ammonia, a process creating the nitrogen-nitrogen single bond. This hydrazone condenses with one more equivalent of ketone; the resulting acetone azine is hydrolyzed to give hydrazine and regenerate the ketone. Unlike the Olin Raschig Process, this approach does not produce a salt as a by-product.[16]

Applications

The majority use of hydrazine is as a precursor to blowing agents. Specific compounds include azodicarbonamide and azobisisobutyronitrile, which yield 100-200 mL of gas per gram of precursor. In a related application, sodium azide, the gas-forming agent in air bags, is produced from hydrazine by reaction with sodium nitrite.[8]

Hydrazine is also used as a propellant on board space vehicles, and to both reduce the concentration of dissolved oxygen in and control pH of water used in large industrial boilers. The F-16 fighter jet uses hydrazine to fuel the aircraft's emergency power unit.

Precursor to pesticides and pharmaceuticals

Hydrazine is a useful building block in organic synthesis of pharmaceuticals and pesticides. One example is 3-amino-1,2,4-triazole and another is maleic hydrazide. The antitubercular drug isoniazid is prepared from hydrazine.

Hydrazine in biology

Hydrazine is the intermediate in the anaerobic oxidation of ammonia (anammox) process.[17] It is produced by some yeasts and the open ocean bacterium anammox (Brocadia anammoxidans).[18] The false morel produces the poison gyromitrin which is an organic derivative of hydrazine that is converted to monomethylhydrazine by metabolic processes. Even the most popular edible "button" mushroom Agaricus bisporus produces organic hydrazine derivatives, including agaritine, a hydrazine derivative of an amino acid, and gyromitrin.[19][20]

Organic chemistry

Hydrazines are part of many organic syntheses, often those of practical significance in pharmaceuticals, such as the antituberculosis medication isoniazid and the antifungal fluconazole, as well as in textile dyes and in photography.[8]

Hydrazone formation

Illustrative of the condensation of hydrazine with a simple carbonyl is its reaction with propanone to give the diisopropylidene hydrazine (acetone azine). The latter reacts further with hydrazine to yield the hydrazone:[21]

2 (CH3)2CO + N2H4 → 2 H2O + [(CH3)2C=N]2
[(CH3)2C=N]2 + N2H4 → 2 (CH3)2C=NNH2

The propanone azine is an intermediate in the Atofina-PCUK process. Direct alkylation of hydrazines with alkyl halides in the presence of base yields alkyl-substituted hydrazines, but the reaction is typically inefficient due to poor control on level of substitution (same as in ordinary amines). The reduction of hydrazones to hydrazines present a clean way to produce 1,1-dialkylated hydrazines.

In a related reaction, 2-cyanopyridines react with hydrazine to form amide hydrazides, which can be converted using 1,2-diketones into triazines.

Wolff-Kishner reduction

Hydrazine is used in the Wolff-Kishner reduction, a reaction that transforms the carbonyl group of a ketone into a methylene bridge (or an aldehyde into a methyl group) via a hydrazone intermediate. The production of the highly stable dinitrogen from the hydrazine derivative helps to drive the reaction.

Heterocyclic chemistry

Being bifunctional, with two amines, hydrazine is a key building block for the preparation of many heterocyclic compounds via condensation with a range of difunctional electrophiles. With 2,4-pentanedione, it condenses to give the 3,5-dimethylpyrazole.[22] In the Einhorn-Brunner reaction hydrazines react with imides to give triazoles.

Sulfonation

Being a good nucleophile, N2H4 can attack sulfonyl halides and acyl halides.[23] The tosylhydrazine also forms hydrazones upon treatment with carbonyls.

Deprotection of phthalimides

Hydrazine is used to cleave N-alkylated phthalimide derivatives. This scission reaction allows phthalimide anion to be used as amine precursor in the Gabriel synthesis.[24]

Reducing agent

Hydrazine is a convenient reductant because the by-products are typically nitrogen gas and water. Thus, it is used as an antioxidant, an oxygen scavenger, and a corrosion inhibitor in water boilers and heating systems. It is also used to reduce metal salts and oxides to the pure metals in electroless nickel plating and plutonium extraction from nuclear reactor waste. Some colour photographic processes also use a weak solution of hydrazine as a stabilizing wash, as it scavenges dye coupler and unreacted silver halides. Hydrazine is the most common and effective reducing agent used to convert graphene oxide (GO) to reduced graphene oxide (rGO) via hydrothermal treatment.[25]

Hydrazinium salts

Hydrazine is converted to solid salts by treatment with mineral acids. A common salt is hydrazine sulfate, [N2H5]HSO4, called hydrazinium sulfate.[26] Hydrazine sulfate was investigated as a treatment of cancer-induced cachexia, but proved ineffective.[27]

Hydrazine azide (N5H5), the salt of hydrazine and hydrazoic acid, was of scientific interest, because of its high nitrogen content and explosive properties. Structurally, it is [N
2H
5]+
[N
3]−
. It decomposes explosively into hydrazine, ammonia and nitrogen gas:[28]

12 N
5H
5 → 3 N
2H
4 + 16 NH
3 + 19 N
2

Reaction of N
5H
5 with sulfuric acid gives quantitative yields of pure hydrazine sulfate and hydrazoic acid.[29]

Other industrial uses

Hydrazine is used in many processes including: production of spandex fibers, as a polymerization catalyst; in fuel cells, solder fluxes; and photographic developers, as a chain extender in urethane polymerizations, and heat stabilizers. In addition, a semiconductor deposition technique using hydrazine has recently been demonstrated, with possible application to the manufacture of thin-film transistors used in liquid crystal displays. Hydrazine in a 70% hydrazine, 30% water solution is used to power the EPU (emergency power unit) on the Lockheed F-16 Fighting Falcon fighter plane. The explosive Astrolite is made by combining hydrazine with ammonium nitrate.

Hydrazine is often used as an oxygen scavenger and corrosion inhibitor in boiler water treatment. However due to the toxicity and certain undesired effects this practice is discouraged.

Rocket fuel

Anhydrous hydrazine being loaded into the MESSENGER space probe. Note the safety suit the technician is wearing

Hydrazine was first used as a rocket fuel during World War II for the Messerschmitt Me 163B (the first rocket-powered fighter plane), under the code name B-Stoff (hydrazine hydrate). When mixed with methanol (M-Stoff) and water it was called C-Stoff.[30]

Hydrazine is also used as a low-power monopropellant for the maneuvering thrusters of spacecraft, and was used to power the Space Shuttle's auxiliary power units (APUs). In addition, monopropellant hydrazine-fueled rocket engines are often used in terminal descent of spacecraft. Such engines were used on the Viking program landers in the 1970s as well as the Phoenix lander and Curiosity rover which landed on Mars in May 2008 and August 2012, respectively.

In all hydrazine monopropellant engines, the hydrazine is passed by a catalyst such as iridium metal supported by high-surface-area alumina (aluminium oxide) or carbon nanofibers,[31] or more recently molybdenum nitride on alumina,[32] which causes it to decompose into ammonia, nitrogen gas, and hydrogen gas according to the following reactions:[33]

  1. 3 N2H4 → 4 NH3 + N2
  2. N2H4 → N2 + 2 H2
  3. 4 NH3 + N2H4 → 3 N2 + 8 H2

Reactions 1 and 2 are extremely exothermic (the catalyst chamber can reach 800 °C in a matter of milliseconds,[31]) and they produce large volumes of hot gas from a small volume of liquid,[32] making hydrazine a fairly efficient thruster propellant with a vacuum specific impulse of about 220 seconds.[34] Reaction 3 is endothermic and so reduces the temperature of the products, but also produces a greater number of molecules. The catalyst structure affects the proportion of the NH3 that is dissociated in Reaction 3; a higher temperature is desirable for rocket thrusters, while more molecules are desirable when the reactions are intended to produce greater quantities of gas.

Other variants of hydrazine that are used as rocket fuel are monomethylhydrazine, (CH3)NH(NH2) (also known as MMH), and unsymmetrical dimethylhydrazine, (CH3)2N(NH2) (also known as UDMH). These derivatives are used in two-component rocket fuels, often together with nitrogen tetroxide, N2O4, sometimes known as dinitrogen tetroxide. These reactions are extremely exothermic, and the burning is also hypergolic, which means that it starts without any external ignition source.[35]

There are ongoing efforts to replace hydrazine along with other highly toxic substances from the aerospace industry. Promising alternatives include hydroxylammonium nitrate, 2-Dimethylaminoethylazide (DMAZ)[36] and energetic ionic liquids.[37]

Fuel cells

The Italian catalyst manufacturer Acta has proposed using hydrazine as an alternative to hydrogen in fuel cells. The chief benefit of using hydrazine is that it can produce over 200 mW/cm2 more than a similar hydrogen cell without the need to use expensive platinum catalysts.[38] As the fuel is liquid at room temperature, it can be handled and stored more easily than hydrogen. By storing the hydrazine in a tank full of a double-bonded carbon-oxygen carbonyl, the fuel reacts and forms a safe solid called hydrazone. By then flushing the tank with warm water, the liquid hydrazine hydrate is released. Hydrazine has a higher electromotive force of 1.56 V compared to 1.23 V for hydrogen. Hydrazine breaks down in the cell to form nitrogen and hydrogen which bonds with oxygen, releasing water.[38] Hydrazine was used in fuel cells manufactured by Allis-Chalmers Corp., including some that provided electric power in space satellites in the 1960s.

Gun propellant

A mixture of 63% hydrazine, 32% hydrazine nitrate and 5% water is a standard propellant for experimental bulk-loaded liquid propellant artillery. The propellant mixture above is one of the most predictable and stable, with a flat pressure profile during firing. Misfires are usually caused by inadequate ignition. The movement of the shell after a misignition causes a large bubble with a larger ignition surface area, and the greater rate of gas production causes very high pressure, sometimes including catastrophic tube failures (i.e. explosions).[39]

Hazards

Hydrazine is highly toxic, and dangerously unstable in the anhydrous form. According to the U.S. Environmental Protection Agency:

Symptoms of acute (short-term) exposure to high levels of hydrazine may include irritation of the eyes, nose, and throat, dizziness, headache, nausea, pulmonary edema, seizures, coma in humans. Acute exposure can also damage the liver, kidneys, and central nervous system. The liquid is corrosive and may produce dermatitis from skin contact in humans and animals. Effects to the lungs, liver, spleen, and thyroid have been reported in animals chronically exposed to hydrazine via inhalation. Increased incidences of lung, nasal cavity, and liver tumors have been observed in rodents exposed to hydrazine.[40]

Limit tests for hydrazine in pharmaceuticals suggest that it should be in the low ppm range.[41] Hydrazine may also cause steatosis.[42] At least one human is known to have died after 6 months of sublethal exposure to hydrazine hydrate.[43]

On February 21, 2008, the United States government destroyed the disabled spy satellite USA 193 with a sea-launched missile, reportedly due to the potential danger of a hydrazine release if it re-entered the Earth's atmosphere intact.[44]

History

The name "hydrazine" was coined by Emil Fischer in 1875; he was trying to produce organic compounds that consisted of mono-substituted hydrazine.[45] By 1887, Theodor Curtius had produced hydrazine sulfate by treating organic diazides with dilute sulfuric acid; however, he was unable to obtain pure hydrazine, despite repeated efforts.[46] Pure anhydrous hydrazine was first prepared by the Dutch chemist Lobry de Bruyn in 1895.[47]

See also

References

  1. ↑ 1.0 1.1 "hydrazine - PubChem Public Chemical Database". The PubChem Project. USA: National Center for Biotechnology Information.
  2. ↑ "NIOSH Guide - Hydrazine". Centers for Disease Control. Retrieved 16 August 2012.
  3. ↑ 3.0 3.1 3.2 3.3 3.4 3.5 "NIOSH Pocket Guide to Chemical Hazards #0329". National Institute for Occupational Safety and Health (NIOSH).
  4. ↑ Hall H.K. (1957). J. Am. Chem. Soc. 79: 5441. doi:10.1021/ja01577a030. Missing or empty |title= (help)
  5. ↑ Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. ISBN 0080379419.
  6. ↑ "Hydrazine safety data sheet".
  7. ↑ Martel, B.; Cassidy, K. (2004). Chemical Risk Analysis: A Practical Handbook. Butterworth–Heinemann. p. 361. ISBN 1-903996-65-1.
  8. ↑ 8.0 8.1 8.2 8.3 8.4 8.5 8.6 Jean-Pierre Schirmann, Paul Bourdauducq "Hydrazine" in Ullmann's Encyclopedia of Industrial Chemistry, Wiley-VCH, Weinheim, 2002. doi:10.1002/14356007.a13_177.
  9. ↑ Miessler, Gary L. and Tarr, Donald A. Inorganic Chemistry, Third Edition Pearson Prentice Hall (2004) ISBN 0-13-035471-6.
  10. ↑ Handbook of Chemistry and Physics", 83rd edition, CRC Press, 2002
  11. ↑ Holleman, A. F.; Wiberg, E. "Inorganic Chemistry" Academic Press: San Diego, 2001. ISBN 0-12-352651-5.
  12. ↑ Chemical Hazard Properties Table at NOAA.gov
  13. ↑ Adams, R.; Brown, B. K. (1941). "Hydrazine Sulfate". Org. Synth.; Coll. Vol. 1, p. 309
  14. ↑ "Hydrazine: Chemical product info". chemindustry.ru. Retrieved 2007-01-08.
  15. ↑ Chemistry of Petrochemical Processes, 2nd edition, Gulf Publishing Company, 1994-2000, Page 148
  16. ↑ Riegel, Emil Raymond (1992). "Riegel's Handbook of Industrial Chemistry". p. 192. |chapter= ignored (help).
  17. ↑ Strous, M., and Jetten, M.S.M. (2004) Anaerobic oxidation of methane and ammonium. Ann Rev Microbiol 58: 99–117.
  18. ↑ Brian Handwerk (9 November 2005). "Bacteria Eat Human Sewage, Produce Rocket Fuel". National Geographic. Retrieved 2007-11-12.
  19. ↑ Hashida C, Hayashi K, Jie L, Haga S, Sakurai M, Shimizu H (June 1990). "[Quantities of agaritine in mushrooms (Agaricus bisporus) and the carcinogenicity of mushroom methanol extracts on the mouse bladder epithelium]". Nippon Koshu Eisei Zasshi (in Japanese) 37 (6): 400–5. PMID 2132000.
  20. ↑ Sieger AA (ed.) (1998-01-01). "Spore Prints #338". Bulletin of the Puget Sound Mycological Society. Retrieved 2008-10-13.
  21. ↑ Day, A. C.; Whiting, M. C. "Acetone Hydrazone". Org. Synth.; Coll. Vol. 6, p. 10
  22. ↑ Wiley, R. H.; Hexner, P. E. "3,5-Dimethylpyrazole". Org. Synth.; Coll. Vol. 4, p. 351
  23. ↑ Friedman, L; Litle, R. L.; Reichle, W. R. "p-Toluenesulfonyl Hydrazide". Org. Synth.; Coll. Vol. 5, p. 1055
  24. ↑ Weinshenker, N. M.; Shen, C. M.; Wong, J. Y. (1988). "Polymeric carbodiimide". Org. Synth.; Coll. Vol. 6, p. 951
  25. ↑ Stankovich et al., Synthesis of graphene-based nanosheets via chemical reduction of exfoliated graphite oxide, Carbon, 45, (2007) 1558–1565
  26. ↑ Safety Data Sheet Mallinckrodt
  27. ↑ Gagnon B, Bruera E (May 1998). "A review of the drug treatment of cachexia associated with cancer". Drugs 55 (5): 675–88. doi:10.2165/00003495-199855050-00005. PMID 9585863.
  28. ↑ G. B. Manelis (2003). Thermal decomposition and combustion of explosives and propellants. CRC Press. p. 235. ISBN 0-415-29984-5.
  29. ↑ Klapötke, T.; Peter S. White; Inis C. Tornieporth-Oetting (1996). "Reaction of hydrazinium azide with sulfuric acid: the X-ray structure of [N
    2    H
    6    ][SO
    4    ]    ". Polyhedron 15 (15): 2579–2582. doi:10.1016/0277-5387(95)00527-7.
  30. ↑ Clark, John D. (1972). Ignition! An Informal History of Liquid Rocket Propellants (PDF). New Brunswick, New Jersey: Rutgers University Press. p. 13. ISBN 0-8135-0725-1.
  31. ↑ 31.0 31.1 Vieira, R.; C. Pham-Huu, N. Keller and M. J. Ledoux (2002). "New carbon nanofiber/graphite felt composite for use as a catalyst support for hydrazine catalytic decomposition". Chemical Communications (9): 954–955. doi:10.1039/b202032g.
  32. ↑ 32.0 32.1 Chen, Xiaowei et al. (April 2002). "Catalytic Decomposition of Hydrazine over Supported Molybdenum Nitride Catalysts in a Monopropellant Thruster". Catalysis Letters 79: 21–25. doi:10.1023/A:1015343922044.
  33. ↑ Haws, J.L.; Harden, D.G. (1965). "Thermodynamic Properties of Hydrazine,". Journal of Spacecraft and Rockets 2 (6): 972–974. doi:10.2514/3.28327.
  34. ↑ Monopropellant Hydrazine Thrusters
  35. ↑ Mitchell, Martha et al. (2007). "Thermodynamic analysis of equations of state for the monopropellant hydrazine". JOURNAL OF THERMOPHYSICS AND HEAT TRANSFER 21: 243–247. doi:10.2514/1.22798.
  36. ↑ "Rocket Propellant Development Efforts at Purdue University - PowerPoint PPT Presentation". Retrieved 21 April 2013.
  37. ↑ Fahrat, Kamal; Batonneau, Yann; Brahmi, Rachid; Kappenstein, Charles (September 22, 2011). "Chapter 21: Application of Ionic Liquids to Space Propulsion". In Handy, Scott. Applications of Ionic Liquids in Science and Technology. InTech. doi:10.5772/23807. ISBN 978-953-307-605-8. Retrieved 2013-07-20.
  38. ↑ 38.0 38.1 "Liquid asset". The Engineer. 2008-01-15. Retrieved 2015-01-09.
  39. ↑ Knapton, John, Stobie, Irvin, Elmore, Les; ARl-TR-81 A review of the Bulk-Loaded Liquid Propellant Gun Program for Possible Relevance to the Electrothermal Chemical Propulsion Program, Army Research Laboratory, March 1993 At Accessed 2011-7-23
  40. ↑ United States Environmental Protection Agency. Hydrazine Hazard Summary-Created in April 1992; Revised in January 2000. Retrieved on February 21, 2008.
  41. ↑ European Pharmacopeia Scientific Notes. Acceptance criteria for levels of hydrazine in substances for pharmaceutical use and analytical methods for its determination. Retrieved on April 22, 2008.
  42. ↑ PHM 450 Course, Spring 2009, Michigan State University
  43. ↑ International Programme on Chemical Safety, Environmental Health Criteria for Hydrazine, Section 9.2.1, dated 1987. Retrieved on February 21, 2008.
  44. ↑ "IEEE Spectrum Online. U.S. Satellite Shootdown". Retrieved 2008-08-08.
  45. ↑ Emil Fischer (1875) "Ueber aromatische Hydrazinverbindungen" (On aromatic hydrazine compounds), Berichte der Deutschen chemischen Gesellschaft zu Berlin, 8 : 589-594.
  46. ↑ See:
  47. ↑ See:
    • C. A. Lobry de Bruyn (1894) "Sur l'hydrazine (diamide) libre" (On free hydrazine (diamide)), Recueil des Travaux Chimiques des Pays-Bas, 13 (8) : 433-440.
    • C. A. Lobry de Bruyn (1895) "Sur l'hydrate d'hydrazine" (On the hydrate of hydrazine), Recueil des Travaux Chimiques des Pays-Bas, 14 (3) : 85-88.
    • C. A. Lobry de Bruyn (1896) "L'hydrazine libre I" (Free hydrazine, Part 1), Recueil des Travaux Chimiques des Pays-Bas, 15 (6) : 174-184.

External links

Look up hydrazine in Wiktionary, the free dictionary.