Hydrazine 69955 225035540 2008-07-11T16:00:15Z Benjah-bmm27 126395 Reverted edits by [[Special:Contributions/128.230.29.117|128.230.29.117]] ([[User talk:128.230.29.117|talk]]) to last version by Alai {{Chembox new | Name = Hydrazine | ImageFile1 = Hydrazine-distances-2D.png | ImageSize1 = 150px | ImageFileR2 = Hydrazine-3D-balls.png | ImageSizeR2 = 120px | ImageFileL2 = Hydrazine-3D-vdW.png | ImageSizeL2 = 120px | IUPACName = Hydrazine | OtherNames = | Section1 = {{Chembox Identifiers | CASNo = 302-01-2 | RTECS = MU7175000 | SMILES = NN }} | Section2 = {{Chembox Properties | Formula = N<sub>2</sub>H<sub>4</sub> | MolarMass = 32.05 g/mol | Appearance = Colourless liquid | Density = 1.01 g/mL (liquid) | Solubility = [[Miscibility|miscible]] | MeltingPt = 1 °C (274 K) | BoilingPt = 114 °C (387 K) | Viscosity = 0.9 [[Poise|cP]] at 25°C<ref name="Greenwood 1997">"Chemistry of the Elements", 2nd ed., Greenwood, N. N. and Earnshaw, A., Butterworth-Heinemann, Oxford (1997).</ref> }} | Section3 = {{Chembox Structure | MolShape = pyramidal at N | Dipole = 1.85 [[Debye|D]]<ref name="Greenwood 1997"/> }} | Section7 = {{Chembox Hazards | MainHazards = Toxic,<br />causes burns | NFPA-H = 3 | NFPA-F = 3 | NFPA-R = 3 | FlashPt = 37.78°C ([[Pensky-Martens closed cup|closed cup]]) | RPhrases = 45-10-23/24/25-34-43-50/53 | SPhrases = 53-45-60-61 | ExternalMSDS = [http://www.sciencelab.com/xMSDS-Hydrazine-9924279 External MSDS] }} | Section8 = {{Chembox Related | Function = hydrides | OtherFunctn = [[hydrogen peroxide]]<br /> [[ammonia]] | OtherCpds = [[monomethylhydrazine]]<br />[[dimethylhydrazine]]<br/>[[phenylhydrazine]]<br/>[[triazane]] }} }} '''Hydrazine''' is a [[chemical compound]] with the [[chemical formula|formula]] N<sub>2</sub>H<sub>4</sub>. It has an [[ammonia]]-like odor, and is derived from the same industrial chemistry processes that manufacture ammonia. However, hydrazine has physical properties that are more similar to those of water. Hydrazine is usually handled as 60% (saturated) [[aqueous solution]] for product safety reasons. Hydrazine is mainly used as a [[blowing agent]] in preparing polymer foams, but significant applications also include its uses as a [[precursor]] to [[polymerization ]] catalysts and [[pharmaceutical]]s. Hydrazine is used as [[rocket fuel]] and to prepare the gas precursors used in [[air bags]]. Approximately 260 thousand tons are manufactured annually.<ref name=Ullmann>Jean-Pierre Schirmann, Paul Bourdauducq "Hydrazine" in Ullmann's Encyclopedia of Industrial Chemistry, Wiley-VCH 2002. DOI: 10.1002/14356007.a13_177. Article Online Posting Date: June 15, 2001</ref> ==Molecular structure and properties== Hydrazine can arise via coupling a pair of [[ammonia]] molecules by removal of one hydrogen per molecule. Each H<sub>2</sub>N-N subunit is pyramidal in shape. The N-N distance is 1.45 Å (145 [[picometer|pm]]), and the molecule adopts a [[gauche conformation]].<ref> Miessler, Gary L. and Tarr, Donald A. '' Inorganic Chemistry, Third Edition''. Pearson Prentice Hall (2004). ISBN 0-13-035471-6.</ref> The [[rotational barrier]] is twice that of [[ethane]]. These structural properties resemble those of gaseous [[hydrogen peroxide]], which adopts a "skewed" [[Linear alkane conformation|anticlinal]] conformation, and also experiences a strong rotational barrier. Hydrazine has [[Base (chemistry)|basic]] ([[alkali]]) chemical properties comparable to those of [[ammonia]] but about 1/15 as strong. :N<sub>2</sub>H<sub>4</sub> + H<sub>2</sub>O → [N<sub>2</sub>H<sub>5</sub>]<sup>+</sup> + OH<sup>-</sup> K<sub>b</sub> = 3.0 x 10<sup>-6</sup> (for ammonia K<sub>b</sub> = 1.78 x 10<sup>-5</sup>) Hydrazine can be diprotonated only with difficulty:<ref>Holleman, A. F.; Wiberg, E. "Inorganic Chemistry" Academic Press: San Diego, 2001. ISBN 0-12-352651-5.</ref> :[N<sub>2</sub>H<sub>5</sub>]<sup>+</sup> + H<sub>2</sub>O → [N<sub>2</sub>H<sub>6</sub>]<sup>2+</sup> + OH<sup>-</sup> K<sub>b</sub> = 8.4 x 10<sup>-16</sup> ==Synthesis and manufacture== [[Theodor Curtius]] synthesized free hydrazine for the first time in 1889 via a [[wiktionary:circuitous|circuitous]] route.<ref>Curtius, ''J. Prakt. Chem''. '''1889''', 39, 107-39.</ref> 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.<ref>{{OrgSynth | author = Adams, R.; Brown, B. K. | title = Hydrazine Sulfate | collvol = 1 | collvolpages = 309 | year = 1941 | prep = cv1p0309}}</ref> Ammonia is readily available from the [[Haber process]]. The Olin Raschig route to hydrazine involves oxidation of [[urea]] with [[sodium hypochlorite]]:<ref>{{cite web|url=http://chemindustry.ru/Hydrazine.php|title=Hydrazine: Chemical product info|publisher=chemindustry.ru|accessdate=2007-01-08}}</ref> :(H<sub>2</sub>N)<sub>2</sub>C=O + NaOCl + 2 NaOH → N<sub>2</sub>H<sub>4</sub> + H<sub>2</sub>O + NaCl + Na<sub>2</sub>CO<sub>3</sub> In the [[Atofina-PCUK cycle]], hydrazine is produced in several steps from [[acetone]], ammonia, and hydrogen peroxide. Acetone and ammonia first react to give the [[imine]] followed by oxidation with [[hydrogen peroxide]] to the [[oxaziridine]], a three-membered ring containing carbon, oxygen, and nitrogen, followed by [[ammonolysis]] to the [[hydrazone]], a process that couples two nitrogen atoms. This hydrazone reacts with one more equivalent of acetone, and the resulting azine is hydrolyzed to give hydrazine, regenerating acetone. Unlike the Raschig process, this process does not produce salt. The PCUK stands for Produits Chimiques Ugine Kuhlmann, a French chemical manufacturer.<ref>Riegel, Emil Raymond. "Hydrazine" ''Riegel's Handbook of Industrial Chemistry'', p. 192 (1992).</ref> Hydrazine can also be produced via the so-called [[ketazine process|ketazine]] and [[peroxide process]]es. It was recently discovered that hydrazine is produced by some yeasts and the open ocean bacterium anammox (''[[Brocadia anammoxidans]]''). They are the only discovered organisms to naturally produce hydrazine.<ref>{{cite news | author = Brian Handwerk | url = http://news.nationalgeographic.com/news/2005/11/1109_051109_rocketfuel.html | title = Bacteria Eat Human Sewage, Produce Rocket Fuel | publisher = [[National Geographic]] |date=9 Nov 2005 | accessdate = 2007-11-12}}</ref> ==Hydrazine derivatives== Many substituted hydrazines are known, and several occur naturally. Some examples: *[[gyromitrin]] and [[agaritine]] are phenylhydrazines found in the commercially produced mushroom species ''[[Agaricus bisporus]]''. [[Gyromitrin]] is metabolized into [[monomethyl hydrazine]]. *[[Isoniazid]], [[iproniazid]], [[hydralazine]] and [[phenelzine]] are hydrazine-containing [[medication]]s. *[[UDMH|1,1-dimethylhydrazine]] and [[1,2-dimethylhydrazine]] are hydrazines where two hydrogen atoms are replaced by [[methyl group]]s. *[[2,4-Dinitrophenylhydrazine|2,4-dinitrophenylhydrazine]] (2,4-DNP) is commonly used to test for [[ketones]] and [[aldehydes]] in [[organic chemistry]]. *[[phenylhydrazine]], C<sub>6</sub>H<sub>5</sub>NHNH<sub>2</sub>, the first hydrazine to be discovered. ==Applications== The majority use of hydrazine is as a precursor to [[blowing agent]]s. Specific compounds include [[azodicarbonamide]] and [[azobis(isobutyronitrile)]], which yield 100-200 mL of gas per gram of precursor. In a somewhat related application, [[sodium azide]], the gas-forming agent in [[air bags]], is produced from hydrazine by reaction with [[sodium nitrite]].<ref name=Ullmann/> Hydrazine is also used in satellites to make adjustments while in orbit. It is also used as a propellant on board space vehicles. ==Organic chemistry== Hydrazines are part of many [[organic syntheses]], often those of practical significance in [[pharmaceutical]]s, such as the [[antituberculant]] [[Isoniazid]] and the antifungal [[Fluconazole]], as well as in textile [[dye]]s and in photography.<ref name=Ullmann/> ===Hydrazone formation=== Illustrative of the condensation of hydrazine with a simple carbonyl is its reaction with propanone to give the diisopropylidene hydrazine. The latter reacts further with hydrazine to afford the hydrazone:<ref>{{OrgSynth | author = Day, A. C.; Whiting, M. C. | title = Acetone Hydrazone | collvol = 6 | collvolpages = 10 | prep = cv6p0010}}</ref> :2 (CH<sub>3</sub>)<sub>2</sub>CO + N<sub>2</sub>H<sub>4</sub> → 2 H<sub>2</sub>O + [(CH<sub>3</sub>)<sub>2</sub>C=N]<sub>2</sub> :[(CH<sub>3</sub>)<sub>2</sub>C=N]<sub>2</sub> + N<sub>2</sub>H<sub>4</sub> → 2 (CH<sub>3</sub>)<sub>2</sub>C=NNH<sub>2</sub> The propanone azine is an intermediate in the Atofina-PCUK synthesis. Direct [[alkylation]] of hydrazines with [[alkyl halides]] in the presence of base affords alkyl-substituted hydrazines, but the reaction is typically inefficient due to poor control on level of substitution (same as in ordinary [[amine]]s). The reduction of [[hydrazone]]s to hydrazines present a clean way to produce 1,1-dialkylated hydrazines. In a related reaction, 2-cyano[[pyridine]]s 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]] or [[aldehyde]] into a [[methylene]] (or [[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]].<ref>{{OrgSynth | author = Wiley, R. H.; Hexner, P. E. | title = 3,5-Dimethylpyrazole | collvol = 4 | collvolpages = 351 | prep = cv4p0351}}</ref> In the [[Einhorn-Brunner reaction]] hydrazines react with imides to give [[triazole]]s. ===Sulfonation=== Being a good nucleophile, N<sub>2</sub>H<sub>4</sub> can attack sulfonyl halides and acyl halides.<ref>{{OrgSynth | author = Friedman, L; Litle, R. L.; Reichle, W. R. | title = ''p''-Toluenesulfonyl Hydrazide | collvol = 5 | collvolpages = 1055 | prep = cv5p1055}}</ref> The [[tosyl]]hydrazine 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]].<ref>{{OrgSynth | author = Weinshenker, N. M.; Shen, C. M.; Wong, J. Y. | title = Polymeric carbodiimide | collvol = 6 | collvolpages = 951 | year = 1988 | prep = cv6p0951}}</ref> ===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 (chemistry)|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|electroless]] [[nickel]] plating and [[plutonium]] extraction from [[nuclear waste|nuclear reactor waste]]. ===Hydrazinium salts=== Hydrazine is converted to solid salts by treatment with mineral acids. A common salt is hydrazine hydrogen [[sulfate]], [N<sub>2</sub>H<sub>5</sub>]HSO<sub>4</sub>, which probably should be called hydrazinium bisulfate.{{Fact|date=January 2008}} Hydrazine bisulfate is used as an alternative treatment of cancer-induced [[cachexia]]. The salt of hydrazine and [[hydrazoic acid]] N<sub>5</sub>H<sub>5</sub> was of scientific interest, because of the high nitrogen content and the explosive properties. ==Other industrial uses== Hydrazine is used in many processes including: production of [[spandex]] fibers, as a [[polymerization]] [[catalyst]]; in [[fuel cell]]s, [[solder]] [[flux (metallurgy)|fluxes]]; and [[photographic developer]]s, as a [[chain extender]] in [[polyurethane|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 transistor]]s used in [[liquid crystal display]]s. Hydrazine in a 70% hydrazine, 30% water solution is used to power the EPU ([[emergency power unit]]) on the [[F-16]] fighter plane. The explosive [[Astrolite]] is made by combining hydrazine with [[ammonium nitrate]]. Hydrazine has also historically been used as an oxygen scavenger in boiler water treatment. However due to the toxicity and certain undesired effects, namely increased rates of flow accelerated corrosion (FAC), this practice is discouraged. ===Rocket fuel=== Hydrazine was first used as a [[rocket fuel]] during [[World War II]] for the [[Messerschmitt Me 163#Me 163 B|Messerschmitt Me 163B]] (the first rocket-powered fighter plane), under the name '''B-Stoff''' (hydrazine [[hydrate]]). If mixed with [[methanol]] ([[M-Stoff]]) and water it was called [[C-Stoff]]. Hydrazine is also used as a low-power [[monopropellant]] for the maneuvering thrusters of spacecraft, and the [[Space Shuttle]]'s Auxiliary Power Units. In addition, monopropellant hydrazine-fueled rocket engines are often used in terminal descent of spacecraft. A collection of such engines was used in both [[Viking program]] landers as well as the [[Phoenix (spacecraft)|Phoenix]] lander launched in August 2007. 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 nanofiber]]s,<ref name="Vieira">{{cite journal | last = Vieira | first = R. | coauthors = C. Pham-Huu, N. Keller and M. J. Ledoux | year = 2002 | title = New carbon nanofiber/graphite felt composite for use as a catalyst support for hydrazine catalytic decomposition | journal = [[Chemical Communications]] | issue = 9 | pages = 954–955 | doi = 10.1039/b202032g}}</ref> or more recently [[molybdenum nitride]] on alumina,<ref name="Chen">{{cite journal | last = Chen | first = Xiaowei | coauthors = ''et al.'' | year = 2002 | month = April | title = Catalytic Decomposition of Hydrazine over Supported Molybdenum Nitride Catalysts in a Monopropellant Thruster | journal = [[Catalysis Letters]] | volume = 79 | pages = 21&ndash;25 | doi = 10.1023/A:1015343922044 }}</ref> which causes it to decompose into [[ammonia]], nitrogen gas, and hydrogen gas according to the following reactions: #3 N<sub>2</sub>H<sub>4</sub> → 4 NH<sub>3</sub> + N<sub>2</sub> #N<sub>2</sub>H<sub>4</sub> → N<sub>2</sub> + 2 H<sub>2</sub> #4 NH<sub>3</sub> + N<sub>2</sub>H<sub>4</sub> → 3 N<sub>2</sub> + 8 H<sub>2</sub> These reactions are extremely [[exothermic]] (the catalyst chamber can reach 800 °C in a matter of milliseconds,<ref name="Vieira" />) and they produce large volumes of hot gas from a small volume of liquid hydrazine,<ref name="Chen" /> making it a fairly efficient thruster propellant with a vacuum [[specific impulse]] of about 220 seconds.<ref>[http://cs.astrium.eads.net/sp/SpacecraftPropulsion/MonopropellantThrusters.html]</ref> Other variants of hydrazine that are used as rocket fuel are [[monomethylhydrazine]], CH<sub>3</sub>NHNH<sub>2</sub> (also known as MMH) and [[unsymmetrical dimethylhydrazine]], (CH<sub>3</sub>)<sub>2</sub>NNH<sub>2</sub> (also known as UDMH). These derivatives are used in two-component rocket fuels, often together with [[dinitrogen tetroxide]], N<sub>2</sub>O<sub>4</sub>, also known as [[nitrogen tetroxide]]. This reaction is extremely exothermic, as a rocket fuel should be, and it is also [[hypergolic]], which means that the burning starts without any external ignition source. ===Fuel cells=== The [[Italy|Italian]] catalyst manufacturer [[Acta (chemical company)|Acta]] has proposed using hydrazine as an alternative to [[hydrogen]] in [[fuel cell]]s. The chief benefit of using hydrazine is that it can produce over 200 m[[watt|W]]/[[centimeter|cm]]<sup>2</sup> more than a similar hydrogen cell without the need to use expensive [[platinum]] catalysts. 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 [[volt|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.<ref name="The Engineer">[http://www.theengineer.co.uk/Articles/303939/Liquid+asset.htm Liquid asset - News - The Engineer - [News: engineering news, engineering info, latest technology, manufacturing news, manufacturing info, automotive news, aerospace news, materials news, research &amp; development&#93;<!-- Bot generated title -->]</ref> Hydrazine was used in fuel cells manufactured by Allis-Chalmers Corp., including some that provided electric power in space satellites in the 1960s. ==Safety== Hydrazine is highly toxic and dangerously unstable, especially in the [[anhydrous]] form. According to the U.S. Environmental Protection Agency:<blockquote> 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.<ref name="EPA">[[United States Environmental Protection Agency]]. ''Hydrazine Hazard Summary-Created in April 1992; Revised in January 2000''[http://www.epa.gov/ttn/atw/hlthef/hydrazin.html]. Retrieved on February 21, 2008.</ref> </blockquote> Limit tests for hydrazine in pharmaceuticals suggest that it should be in the low ppm range <ref name="EuroP">[[European Pharmacopeia Scientific Notes]]. ''Acceptance criteria for levels of hydrazine in substances for pharmaceutical use and analytical methods for its determination''[http://www.ncbi.nlm.nih.gov/sites/entrez/17691211]. Retrieved on April 22, 2008.</ref> At least one human is known to have died from exposure to hydrazine hydrate.<ref>International Programme on Chemical Safety, [http://www.inchem.org/documents/ehc/ehc/ehc68.htm ''Environmental Health Criteria for Hydrazine''], Section 9.2.1, dated 1987. Retrieved on [[21 February]] 2008.</ref> On [[February 21]], [[2008]], the United States government destroyed the disabled spy satellite [[USA 193]] with a sea-launched missile, purportedly due to the potential danger of a hydrazine release if it re-entered the Earth's atmosphere intact. ==References== {{reflist}} ==See also== * [[List of Stoffs]] * [[USA 193]] ==External links== * [http://www.princeton.edu/~orggroup/supergroup_pdf/rmatunasAGM5hydrazine.pdf The Late Show with Rob! Tonight’s Special Guest: Hydrazine (PDF)]&nbsp;&mdash; Robert Matunas * [http://chemindustry.ru/Hydrazine.php Hydrazine - chemical product info: properties, production, applications.] * [http://www.gasdetection.com/TECH/hydrazine.html Hydrazine toxicity] [[Category:Hydrazines| ]] [[Category:Bases]] [[Category:Functional groups]] [[Category:Hazardous air pollutants]] [[Category:Nitrogen compounds]] [[Category:Rocket fuels]] [[Category:Monopropellants]] [[bg:Хидразин]] [[cs:Hydrazin]] [[da:Hydrazin]] [[de:Hydrazin]] [[el:Υδραζίνη]] [[es:Hidrazina]] [[fa:هیدرازین]] [[fr:Hydrazine]] [[ko:하이드라진]] [[it:Idrazina]] [[he:הידרזין]] [[lv:Hidrazīns]] [[lb:Hydrazin]] [[hu:Hidrazin]] [[nl:Hydrazine]] [[ja:ヒドラジン]] [[pl:Hydrazyna]] [[pt:Hidrazina]] [[ru:Гидразин]] [[fi:Hydratsiini]] [[sv:Hydrazin]] [[vi:Hiđrazin]] [[uk:Гідразин]] [[zh:肼]]