Adiponitrile

Adiponitrile
Adiponitrile
Identifiers
CAS number 111-69-3 YesY
ChemSpider 13876621 YesY
UNII VK98I9YW5M YesY
Jmol-3D images Image 1
Properties
Molecular formula C6H8N2
Molar mass 108.14 g mol−1
Appearance Colourless oil
Density 0.97 g/cm3
Melting point

1 °C

Boiling point

295 °C

Solubility in water 50 g/L (20 °C)
Vapor pressure 0.003 hPa (20 °C)
Hazards
R-phrases R23, R25, R36, R38
S-phrases S26, S37, S45
Main hazards Toxic, irritant
NFPA 704
NFPA 704.svg
2
4
1
Flash point 93 °C (decomposition)
Autoignition
temperature
460 °C
Explosive limits 1.7 - 4.9 %V
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Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

Adiponitrile is the organic compound with the formula (CH2)4(CN)2. This dinitrile, a viscous, colourless liquid, is an important precursor to the polymer nylon 66. In 2005, about one billion kilograms were produced annually.[1]

Contents

Production

Early routes

Because of the industrial value of adiponitrile, many methods have been developed for its synthesis. Early industrial routes started from furfural and later by the chlorination of butadiene to give 1,4-dichloro-2-butene, which with sodium cyanide, converts to 3-hexenedinitrile, which in turn can be hydrogenated to adiponitrile:[1]

ClCH2CH=CHCH2Cl + 2 NaCN → NCCH2CH=CHCH2CN + 2 NaCl
NCCH2CH=CHCH2CN + H2 → NC(CH2)4CN

Adiponitrile has also been produced from adipic acid, by dehydration of the diamide, but this route is rarely employed.

Modern routes

The majority of adiponitrile is prepared by the nickel-catalysed hydrocyanation of butadiene, as discovered at duPont. The net reaction is:

CH2=CHCH=CH2 + 2 HCN → NCCH2CH2CH2CH2CN

The process involves several stages, the first of which involves monohydrocyanation (addition of one molecule of HCN), affording isomers of pentenenitriles as well as 2- and 3-methylbutenenitriles. These unsaturated nitriles are subsequently isomerized to the 3-and 4-pentenenitriles. In the final stage, these pentenenitriles are subjected to a second hydrocyanation, in an anti-Markovnikov sense, to produce adiponitrile.[1]

Research has shown that the 3-pentenenitrile, formed in the first hydrocyanation, can undergo alkene metathesis to give dicyanobutenes, which are readily hydrogenated as described above.

The other major industrial route involves electrosynthesis, starting from acrylonitrile, which is dimerized:

2 CH2=CHCN + 2 e- + 2 H+ → NCCH2CH2CH2CH2CN

The electrolytic coupling of acrylonitrile was discovered at Monsanto Company.

Applications

Almost all adiponitrile is hydrogenated to 1,6-diaminohexane for the production of nylon:[2]

NC(CH2)4CN + 4 H2 → H2N(CH2)6NH2

Like other nitriles, adiponitrile is susceptible to hydrolysis. The resulting adipic acid however is more cheaply prepared by other routes.

Safety

The LD50 for adiponitrile is 300 mg/kg for oral ingestion by rats.[1]

In 1990, ACGIH adopted a time weighted average Threshold Limit Value of 2ppm for work related skin exposure. [3]

The NIOSH recommended skin exposure limit for a work related time weighted average concentration is 4ppm (18mg/m3). [4]

References

  1. ^ a b c d M. T. Musser, "Adipic Acid" in Ullmann's Encyclopedia of Industrial Chemistry, Wiley-VCH, Weinheim, 2005. doi:10.1002/14356007.a01 269
  2. ^ Robert A. Smiley "Hexamethylenediamine" in Ullmann's Encyclopedia of Industrial Chemistry, Wiley-VCH, Weinheim, 2005. doi:10.1002/14356007.a12 629
  3. ^ 2009 TLVs and BEIs, American Conference of Governmental Industrial Hygienists, Signature Publications, page 11 of 254.
  4. ^ NIOSH Pocket Guide NIOSH Publication 2005-149; September 2005

External links


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Look at other dictionaries:

  • adiponitrile — ● adiponitrile nom masculin Synonyme de nitrile adipique. ● adiponitrile (synonymes) nom masculin Synonymes : nitrile adipique …   Encyclopédie Universelle

  • adiponitrile — /ad euh poh nuy tril, treel, truyl/, n. Chem. a colorless liquid, C6H8N2, used chiefly as an intermediate in the manufacture of nylon. [ADIPO + NITRILE] * * * …   Universalium

  • adiponitrile — noun A compound with the chemical formula (CH)(CN) …   Wiktionary

  • adiponitrile — ad·i·po·ni·trile …   English syllables

  • adiponitrile — |adə(ˌ)pōˈnī.trə̇l; .ˌtrēl, īl noun ( s) Etymology: adip + nitrile : the high boiling liquid dinitrile NC(CH2)4CN of adipic acid made from 1,4 dichlorobutane and sodium cyanide and used to make the nylon intermediate hexamethylenediamine and… …   Useful english dictionary

  • Hydrocyanation — is, most fundamentally, the process whereby H+ and ndash;CN ions are added to a molecular substrate. Usually the substrate is an alkene and the product is a nitrile. When ndash;CN is a ligand in a transition metal complex, its basicity makes it… …   Wikipedia

  • Hexamethylenediamine — Hexamethylenediamine[1][2] …   Wikipedia

  • adipo- — adip(o) ♦ Élément, du lat. adeps, adipis « graisse ». ⇒ADIPO , élément préf. Sert à former des composés sav. appartenant à la chim., à la physiol., à la méd., etc. Indique gén. la présence normale ou anormale de tissus de nature graisseuse (cf.… …   Encyclopédie Universelle

  • Cyanide — This article is about the class of chemical compounds. For other uses, see Cyanide (disambiguation). The cyanide ion, CN−. From the top: 1. Valence bond structure 2. Space filling model 3. Electrostatic potential surface 4. Carbon lone pair… …   Wikipedia

  • Hydrogen cyanide — IUPAC name …   Wikipedia

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