Acetonitrile 1

Acetonitrile

Acetonitrile

Identifiers

CAS number 75-05-8 [1] 

PubChem 6342 [2]

ChemSpider 6102 [3] 

UNII Z072SB282N [4] 

EC number 200-835-2 [5]

UN number 1648

MeSH acetonitrile [6]

ChEBI CHEBI:38472 [7] 

ChEMBL CHEMBL45211 [8] 

RTECS number AL7700000

Beilstein Reference 741857

Gmelin Reference 895

Jmol-3D images Image 1 [9]

Properties

Molecular formula C2H3N

Molar mass 41.05 g mol−1

Appearance Colorless liquid

Density 786 mg mL−1

Melting point −46 to −44 °C; −51 to −47 °F; 227 to 229 K

Boiling point 81.3 to 82.1 °C; 178.2 to 179.7 °F; 354.4 to 355.2 K

Solubility in water Miscible

log P −0.334

Vapor pressure 9.71 kPa (at 20.0 °C)

kH 530 μmol Pa−1 kg−1

Acidity (pKa) 25

Acetonitrile 2

Basicity (pKb) −11

λmax 195 nm

Absorbance ≤0.10

Refractive index (nD) 1.344

Thermochemistry

Std enthalpy offormation ΔfH

o298

40.16–40.96 kJ mol−1

Std enthalpy ofcombustion ΔcH

o298

−1256.03–−1256.63 kJ mol−1

Standard molarentropy So

298

149.62 J K−1 mol−1

Specific heat capacity, C 91.69 J K−1 mol−1

Hazards

MSDS External MSDS

GHS pictograms

GHS signal word DANGER

GHS hazard statements H225, H302, H312, H319, H332

GHS precautionary statements P210, P280, P305+351+338

EU Index 608-001-00-3

EU classification

F XnR-phrases R11, R20/21/22, R36

S-phrases (S1/2), S16, S36/37

NFPA 704

Flash point 2.0 °C; 35.6 °F; 275.1 K

Autoignition temperature 523.0 °C; 973.4 °F; 796.1 K

Explosive limits 4.4–16.0%

LD50 • 2 g kg−1 (dermal, rabbit)• 2.46 g kg−1 (oral, rat)

Related compounds

Acetonitrile 3

Related alkanenitriles •• Hydrogen cyanide•• Thiocyanic acid•• Cyanogen iodide•• Cyanogen bromide•• Cyanogen chloride•• Cyanogen fluoride•• Aminoacetonitrile•• Glycolonitrile•• Cyanogen•• Propanenitrile•• Aminopropionitrile•• Malononitrile•• Pivalonitrile•• Acetone cyanohydrin

Related compounds DBNPA

Supplementary data page

Structure andproperties

n, εr, etc.

Thermodynamicdata

Phase behaviourSolid, liquid, gas

Spectral data UV, IR, NMR, MS

  (verify) [10] (what is:  / ?)Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)

Infobox references

Acetonitrile is the chemical compound with the formula CH3CN. This colourless liquid is the simplest organic nitrile (hydrogen cyanide is a simpler nitrile, but the cyanideanion is not classed as organic). It is produced mainly as a byproduct of acrylonitrile manufacture. It is used as apolar aprotic solvent in organic synthesis and in the purification of butadiene.[11]

In the laboratory, it is used as a medium-polarity solvent that is miscible with water and range of organic solvents,but not saturated hydrocarbons. It has a convenient liquid range and a high dielectric constant of 38.8. With a dipolemoment of 3.92 D,[12] acetonitrile dissolves a wide range of ionic and nonpolar compounds and is useful as a mobilephase in HPLC and LC-MS. The N-C-C skeleton is linear with a short C-N distance of 1.16 Å.[13]

Acetonitrile was first prepared in 1847 by the French chemist Jean-Baptiste Dumas.[14]

ApplicationsAcetonitrile is used mainly as a solvent in the purification of butadiene in refineries.It is widely used in battery applications because of its relatively high dielectric constant and ability to dissolveelectrolytes. For similar reasons it is a popular solvent in cyclic voltammetry.Its low viscosity and low chemical reactivity make it a popular choice for High-performance liquid chromatography.Acetonitrile plays a significant role as the dominant solvent used in the manufacture of DNA oligonucleotides frommonomers.Industrially, it is used as a solvent for the manufacture of pharmaceuticals and photographic film.

Acetonitrile 4

Organic synthesisAcetonitrile is a common two-carbon building block in organic synthesis of many useful chemicals, includingacetamidine hydrochloride, thiamine, and α-napthaleneacetic acid. Its reaction with cyanogen chloride affordsmalononitrile.

Ligand in coordination chemistryIn inorganic chemistry, acetonitrile is employed as a solvent and often an easily displaceable ligand. For example,PdCl2(CH3CN)2 is prepared by heating a suspension of (polymeric) palladium chloride in acetonitrile:

PdCl2 + 2 CH3CN → PdCl2(CH3CN)2

A related complex is [Cu(MeCN)4]+. The CH3CN groups in these complexes are rapidly displaced by many other ligands.

ProductionAcetonitrile is a by-product from the manufacture of acrylonitrile. Most is combusted to support the intended processbut an estimated several thousand tons are retained for the above mentioned applications. Production trends foracetonitrile thus generally follow those of acrylonitrile. Acetonitrile can also be produced by many other methods,but these are of no commercial importance as of 2002. Illustrative routes are by dehydration of acetamide or byhydrogenation of mixtures of carbon monoxide and ammonia. The main distributors of acetonitrile in the world are:INEOS, Purification Technologies Inc, BioSolve BV, Carlo Erba Reagents, Panreac, J.T. Baker Chemical, VWR,Sigma Aldrich, and Petrolchem Trading Ltd. In 1992[15], 32.3 million pounds (14,700 t) of acetonitrile wereproduced in the US.

Acetonitrile shortage in 2008–2009Starting in October 2008, the worldwide supply of acetonitrile was low because Chinese production was shut downfor the Olympics. Furthermore, a U.S. factory was damaged in Texas during Hurricane Ike. Owing to the globaleconomic slowdown, the production of acrylonitrile that is used in acrylic fibers and acrylonitrile-butadiene-styrene(ABS) resins decreased. Because acetonitrile is a byproduct in the production of acrylonitrile, its production has alsodecreased. The global shortage of acetonitrile continued through early 2009.

Acetonitrile 5

Safety

ToxicityAcetonitrile has only a modest toxicity in small doses. It can be metabolised to produce hydrogen cyanide, which isthe source of the observed toxic effects. Generally the onset of toxic effects is delayed, due to the time required forthe body to metabolize acetonitrile to cyanide (generally about 2–12 hours).Cases of acetonitrile poisoning in humans (or, to be more specific, of cyanide poisoning after exposure toacetonitrile) are rare but not unknown, by inhalation, ingestion and (possibly) by skin absorption. The symptoms,which do not usually appear for several hours after the exposure, include breathing difficulties, slow pulse rate,nausea, and vomiting: Convulsions and coma can occur in serious cases, followed by death from respiratory failure.The treatment is as for cyanide poisoning, with oxygen, sodium nitrite, and sodium thiosulfate among the mostcommonly used remedies.It has been used in formulations for nail polish remover, despite its low but significant toxicity.[16] Acetone and ethylacetate are often preferred as safer for domestic use, and acetonitrile has been banned in cosmetic products in theEuropean Economic Area since March 2000.[17]

Metabolism and excretion

Compound Brain cyanide concentration (µg/kg) Oral LD50

(mg/kg)

Acetonitrile 28±5 2460

Propionitrile 508±84 40

Butyronitrile 437±106 50

Malononitrile 649±209 60

Acrylonitrile 395±106 90

Potassium cyanide 748±200 10

Ionic cyanide concentrations measured in the brains of Sprague-Dawley rats one hour after oral administration of an LD50 of various nitriles.

In common with other nitriles, acetonitrile can be metabolised in microsomes, especially in the liver, to producehydrogen cyanide, as was first shown by Pozzani et al. in 1959. The first step in this pathway is the oxidation ofacetonitrile to glycolonitrile by an NADPH-dependent cytochrome P450 monooxygenase. The glycolonitrile thenundergoes a spontaneous decomposition to give hydrogen cyanide and formaldehyde. Formaldehyde, a toxin and acarcinogen on its own, is further oxidized to formic acid, which is another source of toxicity.The metabolism of acetonitrile is much slower than that of other nitriles, which accounts for its relatively lowtoxicity. Hence, one hour after administration of a potentially lethal dose, the concentration of cyanide in the ratbrain was one-twentieth that for a propionitrile dose 60 times lower (see table).The relatively slow metabolism of acetonitrile to hydrogen cyanide allows more of the cyanide produced to bedetoxified within the body to thiocyanate (the rhodanese pathway). It also allows more of the acetonitrile to beexcreted unchanged before it is metabolised. The main pathways of excretion are by exhalation and in the urine.

Acetonitrile 6

References[1] http:/ / www. commonchemistry. org/ ChemicalDetail. aspx?ref=75-05-8[2] http:/ / pubchem. ncbi. nlm. nih. gov/ summary/ summary. cgi?cid=6342[3] http:/ / www. chemspider. com/ Chemical-Structure. 6102. html[4] http:/ / fdasis. nlm. nih. gov/ srs/ srsdirect. jsp?regno=Z072SB282N[5] http:/ / esis. jrc. ec. europa. eu/ lib/ einecs_IS_reponse. php?genre=ECNO& entree=200-835-2[6] http:/ / www. nlm. nih. gov/ cgi/ mesh/ 2007/ MB_cgi?mode=& term=acetonitrile[7] https:/ / www. ebi. ac. uk/ chebi/ searchId. do?chebiId=38472[8] https:/ / www. ebi. ac. uk/ chembldb/ index. php/ compound/ inspect/ CHEMBL45211[9] http:/ / chemapps. stolaf. edu/ jmol/ jmol. php?model=CC%23N[10] http:/ / en. wikipedia. org/ w/ index. php?title=Special:ComparePages& rev1=477239538& page2=Acetonitrile[11] (http:/ / www. industrialchemistry. info/ 100pagesAddict3. pdf), Ashford's Dictionary of Industrial Chemicals, Third edition, 2011, page 76.[12][12] Steiner, P. A., and Gordy, W., 1966, J. molec. Spectrosc., 21, 291.[13][13] Karakida, Ken-ichi, Tsutomu Fukuyama, and Kozo Kuchitsu. "Molecular Structures of Hydrogen Cyanide and Acetonitrile as Studied by

Gas Electron Diffraction." Bulletin of the Chemical Society of Japan 47.2 (1974): 299-304.[14] Dumas (1847) "Action de l'acide phosphorique anhydre sur les sels ammoniacaux" (http:/ / books. google. com/

books?id=IWFEAQAAIAAJ& pg=PA384#v=onepage& q& f=false) (Action of anhydrous phosphoric acid on ammonium salts), Comptesrendus, 25: 383-384.

[15] http:/ / en. wikipedia. org/ w/ index. php?title=Acetonitrile& action=edit[16][16] At least two cases have been reported of accidental poisoning of young children by acetonitrile-based nail polish remover, one of which was

fatal:[17] Twenty-Fifth Commission Directive 2000/11/EC of 10 March 2000 adapting to technical progress Annex II to Council Directive

76/768/EEC on the approximation of laws of the Member States relating to cosmetic products. (http:/ / eur-lex. europa. eu/ LexUriServ/LexUriServ. do?uri=OJ:L:2000:065:0022:0025:EN:PDF) OJEC L65 of 2000-03-14, pp. 22–25.

External links• WebBook page for C2H3N (http:/ / webbook. nist. gov/ cgi/ cbook. cgi?ID=C75058)• International Chemical Safety Card 0088 (http:/ / www. inchem. org/ documents/ icsc/ icsc/ eics0088. htm)• National Pollutant Inventory - Acetonitrile fact sheet (http:/ / www. npi. gov. au/ database/ substance-info/

profiles/ 4. html)• NIOSH Pocket Guide to Chemical Hazards (http:/ / www. cdc. gov/ niosh/ npg/ npgd0006. html)• Chemical Summary for Acetonitrile (CAS No. 75-05-8) (http:/ / www. epa. gov/ chemfact/ s_acenit. txt), Office

of Pollution Prevention and Toxics, U.S. Environmental Protection Agency• Simulation of acetonitrile (http:/ / www. layruoru. com/ dokuwiki/ doku. php/ solvents)

Article Sources and Contributors 7

Article Sources and ContributorsAcetonitrile  Source: http://en.wikipedia.org/w/index.php?oldid=590269794  Contributors: Alteen88, Alvis, Ambix, Aschwaid, Aussie Alchemist, Beetstra, Benjah-bmm27, BredoteauU2,Brossow, Browneyedgirl13, CMSherwood, Chem-awb, ChemistPyrex, Chemportal, Chris the speller, Christian75, Cian584, Cwkmail, Dandelyonn, DePiep, Dekkanar, Denelson83, Doremo,Drphilharmonic, Edgar181, Ej159, Ekem, Elikrieg, Epop fr, Ferbrunnen, Foobar, Gene Nygaard, Gentgeen, Hakan Kayı, HenkvD, Hermann Luyken, Hnobil, Horoporo, IR8D8R, Ilovebees,Iohannes Animosus, Izmaelt, Jdfalk, Jrtayloriv, Jynto, Karen Johnson, LHcheM, Lamro, Leridant, Louisajb, M stone, Malbi, Materialscientist, Mehcp, Morstar, Mortense, Mullet, Murtasa, NickY., Nicke L, Nono64, NuShrike, Ogre lawless, Peter Corbett, Physchim62, Pikiwyn, Plasmic Physics, Poorjon, Puppy8800, RHWoodman, Radiotrefoil, Raffinate2, Rich Farmbrough, Rifleman82, Rjwilmsi, Russoc4, Rwessel, Saehrimnir, Saehry, Sbyrnes321, Scythe33, Skipmac, Smokefoot, Spiffy sperry, Steve Quinn, Suisui, Superm401, Topbanana, Tyrael123, Ugen64, V8rik,Vchorozopoulos, Vitodang, Wickey-nl, WolfmanSF, YanA, Yellowdesk, Za3bolla elolla, Ziel, Zombiejesus, ~K, 112 anonymous edits

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