|Molar mass||108.14 g·mol−1|
|Density||951 mg mL−1|
|Melting point||1 °C; 34 °F; 274 K|
|Boiling point||295.1 °C; 563.1 °F; 568.2 K|
|50 g/L (20 °C)|
|Vapor pressure||300 mPa (at 20 °C)|
Refractive index (nD)
Std enthalpy of
|84.5–85.3 kJ mol−1|
|GHS signal word||DANGER|
|H301, H315, H319, H330, H335|
|P260, P284, P301+310, P305+351+338, P310|
|S-phrases||S26, S36, S45|
|Flash point||93 °C; 199 °F; 366 K (open cup)|
|550 °C (1,022 °F; 823 K)|
LD50 (Median lethal dose)
|155 mg kg−1 (oral, rat)|
|US health exposure limits (NIOSH):|
|TWA 4 ppm (18 mg/m3)|
IDLH (Immediate danger)
Except where noted otherwise, data is given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
|what is: / ?)(|
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-6,6. In 2005, about one billion kilograms were produced annually.
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:
- 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.
- 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.
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.
- 2 CH2=CHCN + 2 e− + 2 H+ → NCCH2CH2CH2CH2CN
The electrolytic coupling of acrylonitrile was discovered at Monsanto Company.
- 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.
- "adiponitrile - Compound Summary". PubChem Compound. USA: National Center for Biotechnology Information. 26 March 2005. Identification. Retrieved 15 June 2012.
- "NIOSH Pocket Guide to Chemical Hazards #0015". National Institute for Occupational Safety and Health (NIOSH).
- M. T. Musser, "Adipic Acid" in Ullmann's Encyclopedia of Industrial Chemistry, Wiley-VCH, Weinheim, 2005. doi:10.1002/14356007.a01 269
- Robert A. Smiley "Hexamethylenediamine" in Ullmann's Encyclopedia of Industrial Chemistry, Wiley-VCH, Weinheim, 2005. doi:10.1002/14356007.a12 629
- 2009 TLVs and BEIs, American Conference of Governmental Industrial Hygienists, Signature Publications, page 11 of 254.
- NIOSH Pocket Guide NIOSH Publication 2005-149; September 2005