Tetrahydrofuran 240988 224330008 2008-07-08T11:04:06Z Thijs!bot 1392310 robot Adding: [[id:Tetrahidrofuran]] {{Chembox new | Name = Tetrahydrofuran | ImageFileL1 = Tetrahydrofuran-2D-skeletal-A.png | ImageSize = 100px | ImageName = Skeletal formula of tetrahydrofuran | ImageFileR1 = Tetrahydrofuran-3D-balls.png | ImageSizeR1 = 120px | ImageNameR1 = Space-filling model of the THF molecule | IUPACName = Oxacyclopentane | OtherNames = THF, tetrahydrofuran, 1,4-epoxybutane, butylene oxide, cyclotetramethylene oxide, oxacyclopentane, diethylene oxide, oxolane, furanidine, hydrofuran, tetra-methylene oxide | Section1 = {{Chembox Identifiers | SMILES = C1CCCO1 | CASNo = 109-99-9 | RTECS = LU5950000 }} | Section2 = {{Chembox Properties | Formula = C<sub>4</sub>H<sub>8</sub>O | MolarMass = 72.11 g/mol | Appearance = colorless liquid | Density = 0.8892 g/cm<sup>3</sup> @ 20 °C, liquid | Solubility = Miscible | MeltingPt = -108.4 °C (164.75 K) | BoilingPt = 66 °C (339.15 K) | Viscosity = 0.48 cP at 25 °C }} | Section3 = {{Chembox Structure | MolShape = envelope | Dipole = 1.63 [[Debye|D]] (gas) }} | Section7 = {{Chembox Hazards | EUClass = Flammable ('''F''')<br />Irritant ('''Xi''') | NFPA-H = 2 | NFPA-F = 3 | Reactivity=1 | NFPA-R = | RPhrases = {{R11}}, {{R19}}, {{R36/37}} | SPhrases = {{S16}}, {{S29}}, {{S33}} | FlashPt = -14 °C }} | Section8 = {{Chembox Related | Function = [[heterocycle]]s | OtherFunctn = [[Furan]]<br />[[Pyrrolidine]]<br />[[Dioxane]] | OtherCpds = [[Diethyl ether]] }} }} :''"THF" redirects here. For other uses, see [[THF (disambiguation)]]''. '''Tetrahydrofuran''', also known as '''THF''', is a [[Heterocyclic compound|heterocyclic]] [[organic compound]] with the formula (CH<sub>2</sub>)<sub>4</sub>O). It is a colourless low-[[viscosity]] liquid with a smell similar to [[diethyl ether]]. It is one of the most [[polar molecule|polar]] [[ether]]s. THF is the fully [[Hydrogenation|hydrogenated]] analog of the [[aromatic]] compound [[furan]]. ==Solvent properties== THF is an [[Protic solvent|aprotic]] [[solvent]] with a [[dielectric constant]] of 7.6. It is a moderately polar, aprotic solvent that dissolves a wide range of nonpolar and polar compounds. [[Diethyl ether]] can often be substituted by THF when a higher-boiling solvent is required. Thus THF, like diethyl ether, is often used for [[hydroboration]]s used to synthesize [[primary alcohols]]. Both ethers have an oxygen atom which can coordinate to the electron-deficient boron atom, forming an [[adduct]]. Similarly, THF or diethyl ether are often used as solvents for [[Grignard reagent]]s because of the oxygen atom's ability to coordinate to the magnesium ion component of the Grignard reagent. In addition, the oxygen atom has no acid hydrogen that can undergo acid-base reaction with the Grignard reagent. [[2-methyltetrahydrofuran]] has become a popular THF alternative, based on its similar properties to THF, but having a lower melting point (useful for lower temperature reactions), as well as having a higher boiling point (useful for solvent retention under reflux). THF is often used in polymer science. For example, it can be used to dissolve [[rubber]] prior to determining its molecular mass using [[gel permeation chromatography]]. THF dissolves PVC as well, and is the main ingredient in PVC adhesives. It can be used to liquefy old PVC cement. THF can be [[polymerized]] by strong acids to give a linear polymer called [[poly(tetramethylene ether) glycol]] (PTMEG), [[CAS Registry Number]] [25190-06-1], also known as PTMO, polytetramethylene oxide. The primary use of this polymer is to make [[elastomeric]] [[polyurethane]] fibers like [[Spandex]].<ref name="kirk">{{cite encyclopedia |year=1996 |title =Polyethers, Tetrahydrofuran and Oxetane Polymers by Gerfried Pruckmayr, P. Dreyfuss, M. P. Dreyfuss |encyclopedia=Kirk‑Othmer Encyclopedia of Chemical Technology |publisher=John Wiley & Sons, Inc |location= |id= }}</ref>. It is often used industrially to [[grease (lubricant)|degrease]] metal parts. ==Preparation== THF can be synthesized by catalytic [[hydrogenation]] of [[furan]]<ref name="m_and_b">Morrison, Robert Thornton; Boyd, Robert Neilson: ''Organic Chemistry'', 2nd ed., Allyn and Bacon 1972, p 569</ref>. The major industrial process for making THF is the acid-catalyzed dehydration of [[1,4-Butanediol|1,4-butanediol]].<ref name="kirk1">{{cite encyclopedia | title =Ethers, by Lawrence Karas and W. J. Piel | encyclopedia =Kirk‑Othmer Encyclopedia of Chemical Technology | volume = | pages = | publisher =John Wiley & Sons, Inc | date =2004 | id = | accessdate =2007-09-05}}</ref> [[Du Pont]] developed a process for producing THF by [[oxidizing]] [[n-butane]] to crude [[maleic anhydride]], followed by catalytic [[hydrogenation]] of [[maleic anhydride]] to THF.<ref name="kirk1"/><ref name="merck">''Merck Index of Chemicals and Drugs'', 9th ed. monograph 8929</ref> ==Precautions== THF tends to form [[organic peroxide|peroxide]]s on storage in air. As a result, THF should not be distilled to dryness, which can leave a residue of highly-explosive peroxides. Commercial THF is therefore often inhibited with [[butylated hydroxytoluene|BHT]]. ==See also== * The [[Trapp mixture]] extends the temperature range applicability of THF as a solvent. ==References== <references/> * Loudon, G. Mark. ''Organic Chemistry 4th ed.'' New York: Oxford University Press. 2002. pg 318. ==External links== *[http://www.ilo.org/public/english/protection/safework/cis/products/icsc/dtasht/_icsc05/icsc0578.htm International Chemical Safety Card 0578] *[http://www.cdc.gov/niosh/npg/npgd0602.html NIOSH Pocket Guide to Chemical Hazards] * THF usage on [http://www.orgsyn.org/orgsyn/chemname.asp?nameID=35996 Organic Syntheses] * [http://www.camd.lsu.edu/msds/t/tetrahydrofuran.htm THF info] * [http://www.osha-slc.gov/SLTC/healthguidelines/tetrahydrofuran/ U.S. OSHA info on THF] * {{cite web| url=http://www.sigmaaldrich.com/Area_of_Interest/Research_Essentials/Solvents/Key_Resources/Me_THF.html| title=2-Methyltetrahydrofuran, An alternative to Tetrahydrofuran and Dichloromethane|publisher=Sigma-Aldrich|accessdate=2007-05-23}} * {{cite web|url=http://www.basf.com/diols/pdfs/thf_brochure.pdf|title=Tetrahydrafuran (THF) Storage and Handling|publisher=BASF|accessdate=2007-05-24}} [[Category:Ethers]] [[Category:Ether solvents]] [[Category:Oxygen heterocycles]] [[de:Tetrahydrofuran]] [[es:Tetrahidrofurano]] [[fr:Tétrahydrofurane]] [[id:Tetrahidrofuran]] [[it:Tetraidrofurano]] [[lv:THF]] [[nl:Tetrahydrofuraan]] [[ja:テトラヒドロフラン]] [[pl:Tetrahydrofuran]] [[pt:Tetraidrofurano]] [[ru:Тетрагидрофуран]] [[fi:Tetrahydrofuraani]] [[sv:Tetrahydrofuran]] [[zh:四氢呋喃]]