Acetonitrile



























































































































































































































































Acetonitrile





Skeletal formula of acetonitrile


Skeletal formula of acetonitrile with all explicit hydrogens added







Ball and stick model of acetonitrile


Spacefill model of acetonitrile


Names

Preferred IUPAC name
Acetonitrile[2]


Systematic IUPAC name
Ethanenitrile[2]

Other names

  • Cyanomethane[1]

  • Ethyl nitrile[1]

  • Methanecarbonitrile[1]

  • Methyl cyanide[1]


Identifiers

CAS Number



  • 75-05-8 ☑Y


3D model (JSmol)


  • Interactive image


Beilstein Reference

741857

ChEBI


  • CHEBI:38472 ☑Y


ChEMBL


  • ChEMBL45211 ☑Y


ChemSpider


  • 6102 ☑Y


ECHA InfoCard

100.000.760

EC Number
200-835-2

Gmelin Reference

895

MeSH

acetonitrile


PubChem CID


  • 6342


RTECS number
AL7700000

UNII


  • Z072SB282N ☑Y


UN number
1648




Properties

Chemical formula


C2H3N

Molar mass

7001410530000000000♠41.053 g·mol−1
Appearance
Colorless liquid

Odor
Faint, distinct, fruity

Density
0.786 g/cm3

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)


Henry's law
constant (kH)

530 μmol/(Pa·kg)

Acidity (pKa)
25

Basicity (pKb)
−11

UV-vis (λmax)
195 nm

Absorbance
≤0.10


Magnetic susceptibility (χ)


3004720000000000000♠−28.0×10−6 cm3/mol


Refractive index (nD)

1.344
Thermochemistry


Heat capacity (C)

91.69 J/(K·mol)


Std molar
entropy (So298)

149.62 J/(K·mol)


Std enthalpy of
formation fHo298)

40.16–40.96 kJ/mol


Std enthalpy of
combustion cHo298)

−1256.03 – −1256.63 kJ/mol
Hazards

Safety data sheet

See: data page

GHS pictograms

The flame pictogram in the Globally Harmonized System of Classification and Labelling of Chemicals (GHS)The exclamation-mark pictogram in the Globally Harmonized System of Classification and Labelling of Chemicals (GHS)

GHS signal word

DANGER

GHS hazard statements


H225, H302, H312, H319, H332

GHS precautionary statements


P210, P280, P305+351+338

NFPA 704



Flammability code 3: Liquids and solids that can be ignited under almost all ambient temperature conditions. Flash point between 23 and 38 °C (73 and 100 °F). E.g., gasoline
Health code 2: Intense or continued but not chronic exposure could cause temporary incapacitation or possible residual injury. E.g., chloroform
Reactivity code 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g., liquid nitrogen
Special hazards (white): no code
NFPA 704 four-colored diamond


3


2


0



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%
Lethal dose or concentration (LD, LC):


LD50 (median dose)



  • 2 g/kg (dermal, rabbit)

  • 2.46 g/kg (oral, rat)




LC50 (median concentration)

5655 ppm (guinea pig, 4 hr)
2828 ppm (rabbit, 4 hr)
53,000 ppm (rat, 30 min)
7500 ppm (rat, 8 hr)
2693 ppm (mouse, 1 hr)[4]


LCLo (lowest published)

16,000 ppm (dog, 4 hr)[4]
US health exposure limits (NIOSH):


PEL (Permissible)

TWA 40 ppm (70 mg/m3)[3]


REL (Recommended)

TWA 20 ppm (34 mg/m3)[3]


IDLH (Immediate danger)

500 ppm[3]
Related compounds

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 and
properties


Refractive index (n),
Dielectric constant (εr), etc.

Thermodynamic
data


Phase behaviour
solid–liquid–gas

Spectral data


UV, IR, NMR, MS

Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).


☑Y verify (what is ☑Y☒N ?)

Infobox references



Acetonitrile is the chemical compound with the formula CH
3
CN
. This colourless liquid is the simplest organic nitrile (hydrogen cyanide is a simpler nitrile, but the cyanide anion is not classed as organic). It is produced mainly as a byproduct of acrylonitrile manufacture. It is used as a polar aprotic solvent in organic synthesis and in the purification of butadiene.[5]


In the laboratory, it is used as a medium-polarity solvent that is miscible with water and a range of organic solvents, but not saturated hydrocarbons. It has a convenient liquid range and a high dielectric constant of 38.8. With a dipole moment of 3.92 D,[6] acetonitrile dissolves a wide range of ionic and nonpolar compounds and is useful as a mobile phase in HPLC and LC–MS. The N≡C−C skeleton is linear with a short C≡N distance of 1.16 Å.[7]


Acetonitrile was first prepared in 1847 by the French chemist Jean-Baptiste Dumas.[8]




Contents






  • 1 Applications


    • 1.1 Organic synthesis


    • 1.2 Ligand in coordination chemistry




  • 2 Production


    • 2.1 Acetonitrile shortage in 2008–2009




  • 3 Safety


    • 3.1 Toxicity


      • 3.1.1 Metabolism and excretion






  • 4 See also


  • 5 References


  • 6 External links





Applications


Acetonitrile is used mainly as a solvent in the purification of butadiene in refineries. Specifically, acetonitrile is fed into the top of a distillation column filled with hydrocarbons including butadiene, and as the acetonitrile falls down through the column, it absorbs the butadiene which is then sent from the bottom of the tower to a second separating tower. Heat is then employed in the separating tower to separate the butadiene.


It is widely used in battery applications because of its relatively high dielectric constant and ability to dissolve electrolytes. For similar reasons it is a popular solvent in cyclic voltammetry.


Its ultraviolet transparency UV cutoff, low viscosity and low chemical reactivity make it a popular choice for high-performance liquid chromatography (HPLC).


Acetonitrile plays a significant role as the dominant solvent used in the manufacture of DNA oligonucleotides from monomers.


Industrially, it is used as a solvent for the manufacture of pharmaceuticals and photographic film.[9]



Organic synthesis


Acetonitrile is a common two-carbon building block in organic synthesis[10] of many useful chemicals, including acetamidine hydrochloride, thiamine, and α-napthaleneacetic acid.[11] Its reaction with cyanogen chloride affords malononitrile.[5]



Ligand in coordination chemistry


Acetonitrile is a ligand in many transition metal nitrile complexes. Being weakly basic, it is an easily displaceable ligand. For example, bis(acetonitrile)palladium dichloride is prepared by heating a suspension of palladium chloride in acetonitrile:[12]



PdCl
2
+ 2 CH
3
CN
PdCl
2
(CH
3
CN)
2


A related complex is [Cu(CH3CN)4]+. The CH
3
CN
groups in these complexes are rapidly displaced by many other ligands.



Production


Acetonitrile is a byproduct from the manufacture of acrylonitrile. Most is combusted to support the intended process but an estimated several thousand tons are retained for the above-mentioned applications.[13] Production trends for acetonitrile 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 by hydrogenation of mixtures of carbon monoxide and ammonia.[14] In 1992[update], 14,700 tonnes (32,400,000 lb) of acetonitrile were produced in the US.


Catalytic ammoxidation of ethylene was also researched.[15]



Acetonitrile shortage in 2008–2009


Starting in October 2008, the worldwide supply of acetonitrile was low because Chinese production was shut down for the Olympics. Furthermore, a U.S. factory was damaged in Texas during Hurricane Ike.[16] Due to the global economic slowdown, the production of acrylonitrile that is used in acrylic fibers and acrylonitrile butadiene styrene (ABS) resins decreased. Acetonitrile is a byproduct in the production of acrylonitrile and its production also decreased, further compounding the acetonitrile shortage.[17] The global shortage of acetonitrile continued through early 2009.[needs update]



Safety



Toxicity


Acetonitrile has only modest toxicity in small doses.[11][18] It can be metabolised to produce hydrogen cyanide, which is the source of the observed toxic effects.[9][19][20] Generally the onset of toxic effects is delayed, due to the time required for the body to metabolize acetonitrile to cyanide (generally about 2–12 hours).[11]


Cases of acetonitrile poisoning in humans (or, to be more specific, of cyanide poisoning after exposure to acetonitrile) are rare but not unknown, by inhalation, ingestion and (possibly) by skin absorption.[19] 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 most commonly used emergency treatments.[19]


It has been used in formulations for nail polish remover, despite its toxicity. At least two cases have been reported of accidental poisoning of young children by acetonitrile-based nail polish remover, one of which was fatal.[21]Acetone and ethyl acetate are often preferred as safer for domestic use, and acetonitrile has been banned in cosmetic products in the European Economic Area since March 2000.[22]



Metabolism and excretion












































Compound
Brain cyanide concentration (µg/kg)
Oral LD50 (mg/kg)

Potassium cyanide
748 ± 200
10

Propionitrile
508 ± 84
40

Butyronitrile
437 ± 106
50

Malononitrile
649 ± 209
60

Acrylonitrile
395 ± 106
90

Acetonitrile
28 ± 5
2460

Table Salt
n/a
3000

Ionic cyanide concentrations measured in the brains of Sprague-Dawley rats one hour after oral administration of an LD50 of various nitriles.[23]

In common with other nitriles, acetonitrile can be metabolised in microsomes, especially in the liver, to produce hydrogen cyanide, as was first shown by Pozzani et al. in 1959.[24] The first step in this pathway is the oxidation of acetonitrile to glycolonitrile by an NADPH-dependent cytochrome P450 monooxygenase. The glycolonitrile then undergoes a spontaneous decomposition to give hydrogen cyanide and formaldehyde.[18][19] Formaldehyde, a toxin and a carcinogen 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 low toxicity. Hence, one hour after administration of a potentially lethal dose, the concentration of cyanide in the rat brain was ​120 that for a propionitrile dose 60 times lower (see table).[23]


The relatively slow metabolism of acetonitrile to hydrogen cyanide allows more of the cyanide produced to be detoxified within the body to thiocyanate (the rhodanese pathway). It also allows more of the acetonitrile to be excreted unchanged before it is metabolised. The main pathways of excretion are by exhalation and in the urine.[18][19][20]



See also



  • Trichloroacetonitrile – a derivative of acetonitrile used to protect alcohol groups, and also used as a reagent in the Overman rearrangement


References





  1. ^ abcd "Material Safety Data Sheet" (PDF)..mw-parser-output cite.citation{font-style:inherit}.mw-parser-output .citation q{quotes:"""""""'""'"}.mw-parser-output .citation .cs1-lock-free a{background:url("//upload.wikimedia.org/wikipedia/commons/thumb/6/65/Lock-green.svg/9px-Lock-green.svg.png")no-repeat;background-position:right .1em center}.mw-parser-output .citation .cs1-lock-limited a,.mw-parser-output .citation .cs1-lock-registration a{background:url("//upload.wikimedia.org/wikipedia/commons/thumb/d/d6/Lock-gray-alt-2.svg/9px-Lock-gray-alt-2.svg.png")no-repeat;background-position:right .1em center}.mw-parser-output .citation .cs1-lock-subscription a{background:url("//upload.wikimedia.org/wikipedia/commons/thumb/a/aa/Lock-red-alt-2.svg/9px-Lock-red-alt-2.svg.png")no-repeat;background-position:right .1em center}.mw-parser-output .cs1-subscription,.mw-parser-output .cs1-registration{color:#555}.mw-parser-output .cs1-subscription span,.mw-parser-output .cs1-registration span{border-bottom:1px dotted;cursor:help}.mw-parser-output .cs1-ws-icon a{background:url("//upload.wikimedia.org/wikipedia/commons/thumb/4/4c/Wikisource-logo.svg/12px-Wikisource-logo.svg.png")no-repeat;background-position:right .1em center}.mw-parser-output code.cs1-code{color:inherit;background:inherit;border:inherit;padding:inherit}.mw-parser-output .cs1-hidden-error{display:none;font-size:100%}.mw-parser-output .cs1-visible-error{font-size:100%}.mw-parser-output .cs1-maint{display:none;color:#33aa33;margin-left:0.3em}.mw-parser-output .cs1-subscription,.mw-parser-output .cs1-registration,.mw-parser-output .cs1-format{font-size:95%}.mw-parser-output .cs1-kern-left,.mw-parser-output .cs1-kern-wl-left{padding-left:0.2em}.mw-parser-output .cs1-kern-right,.mw-parser-output .cs1-kern-wl-right{padding-right:0.2em}


  2. ^ ab Nomenclature of Organic Chemistry : IUPAC Recommendations and Preferred Names 2013 (Blue Book). Cambridge: The Royal Society of Chemistry. 2014. p. 902. doi:10.1039/9781849733069-FP001. ISBN 978-0-85404-182-4.


  3. ^ abc "NIOSH Pocket Guide to Chemical Hazards #0006". National Institute for Occupational Safety and Health (NIOSH).


  4. ^ ab "Acetonitrile". Immediately Dangerous to Life and Health Concentrations (IDLH). National Institute for Occupational Safety and Health (NIOSH).


  5. ^ ab "Archived copy" (PDF). Ashford's Dictionary of Industrial Chemicals, Third edition. p. 76. Archived from the original (PDF) on 2011-05-16. Retrieved 2011-03-31.CS1 maint: Archived copy as title (link)


  6. ^ Steiner, P. A.; Gordy, W. (1966). "Journal of Molecular Spectroscopy". 21: 291.


  7. ^ Karakida, Ken'ichi; Fukuyama, Tsutomu; Kuchitsu, Kozo (1974). "Molecular Structures of Hydrogen Cyanide and Acetonitrile as Studied by Gas Electron Diffraction". Bulletin of the Chemical Society of Japan. 47 (2): 299–304. doi:10.1246/bcsj.47.299.


  8. ^ Dumas, J.-B. (1847). "Action de l'acide phosphorique anhydre sur les sels ammoniacaux" [Action of anhydrous phosphoric acid on ammonium salts]. Comptes rendus. 25: 383–384.


  9. ^ ab Spanish Ministry of Health (2002), Acetonitrile. Summary Risk Assessment Report (PDF), Ispra (VA), Italy: European Chemicals Bureau, Special Publication I.01.65, archived from the original (PDF) on 2008-12-17


  10. ^ DiBiase, S. A.; Beadle, J. R.; Gokel, G. W. "Synthesis of α,β-Unsaturated Nitriles from Acetonitrile: Cyclohexylideneacetonitrile and Cinnamonitrile". Organic Syntheses.; Collective Volume, 7, p. 108


  11. ^ abc Philip Wexler, ed. (2005), Encyclopedia of Toxicology, Vol. 1 (2nd ed.), Elsevier, pp. 28–30, ISBN 0-12-745354-7


  12. ^ Jürgen-Hinrich., Fuhrhop, (2003). Organic synthesis : concepts and methods. Li, Guangtao, Dr. (3rd, completely rev. and enl. ed.). Weinheim: Wiley-VCH. p. 26. ISBN 9783527302727. OCLC 51068223.


  13. ^ Pollak, Peter; Romeder, Gérard; Hagedorn, Ferdinand; Gelbke, Heinz-Peter, "Nitriles", Ullmann's Encyclopedia of Industrial Chemistry, Weinheim: Wiley-VCH, doi:10.1002/14356007.a17_363


  14. ^ US 4179462, Olive, G. & Olive, S., "Process for preparing acetonitrile", published 1979-12-18, assigned to Monsanto Company 


  15. ^ Rhimi, B.; Mhamdi, M.; Ghorbel, A.; Narayana Kalevaru, V.; Martin, A.; Perez-Cadenas, M.; Guerrero-Ruiz, A. (15 May 2016). "Ammoxidation of ethylene to acetonitrile over vanadium and molybdenum supported zeolite catalysts prepared by solid-state ion exchange". Journal of Molecular Catalysis A: Chemical. 416: 127–139. doi:10.1016/j.molcata.2016.02.028.


  16. ^ Lowe, Derek (2009). "The Great Acetonitrile Shortage". Science Translational Medicine.


  17. ^ A. Tullo. "A Solvent Dries Up". Chemical & Engineering News. 86: 27. doi:10.1021/cen-v086n047.p027.


  18. ^ abc Institut national de recherche et de sécurité (INRS) (2004), Fiche toxicologique no. 104 : Acétonitrile (PDF), Paris: INRS, ISBN 2-7389-1278-8, archived from the original (PDF) on 2011-07-28, retrieved 2008-08-19


  19. ^ abcde International Programme on Chemical Safety (1993), Environmental Health Criteria 154. Acetonitrile, Geneva: World Health Organization


  20. ^ ab Greenberg, Mark (1999), Toxicological Review of Acetonitrile (PDF), Washington, DC: U.S. Environmental Protection Agency


  21. ^ Caravati, E. M.; Litovitz, T. (1988). "Pediatric cyanide intoxication and death from an acetonitrile-containing cosmetic". J. Am. Med. Assoc. 260 (23): 3470–73. doi:10.1001/jama.260.23.3470. PMID 3062198.


  22. ^ "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". Official Journal of the European Communities. L65: 22–25. 2000-03-14.


  23. ^ ab Ahmed, A. E.; Farooqui, M. Y. H. (1982), "Comparative toxicities of aliphatic nitriles", Toxicol. Lett., 12 (2–3): 157–64, doi:10.1016/0378-4274(82)90179-5, PMID 6287676


  24. ^ Pozzani, U. C.; Carpenter, C. P.; Palm, P. E.; Weil, C. S.; Nair, J. H. (1959), "An investigation of the mammalian toxicity of acetonitrile", J. Occup. Med., 1 (12): 634–642, doi:10.1097/00043764-195912000-00003, PMID 14434606




External links



  • WebBook page for C2H3N

  • International Chemical Safety Card 0088

  • National Pollutant Inventory - Acetonitrile fact sheet

  • NIOSH Pocket Guide to Chemical Hazards


  • Chemical Summary for Acetonitrile (CAS No. 75-05-8), Office of Pollution Prevention and Toxics, U.S. Environmental Protection Agency

  • Simulation of acetonitrile










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