Acetonitrile

Acetonitrile
Names
Preferred IUPAC name
Acetonitrile
Systematic IUPAC name
Ethanenitrile
Other names
  • Cyanomethane
  • Ethyl nitrile
  • Methanecarbonitrile
  • Methyl cyanide
  • MeCN
  • ACN
Identifiers
3D model (JSmol)
741857
ChEBI
ChEMBL
ChemSpider
ECHA InfoCard 100.000.760
EC Number
  • 200-835-2
895
MeSH acetonitrile
RTECS number
  • AL7700000
UNII
UN number 1648
  • InChI=1S/C2H3N/c1-2-3/h1H3 Y
    Key: WEVYAHXRMPXWCK-UHFFFAOYSA-N Y
  • CC#N
Properties
C2H3N
Molar mass 41.053 g·mol−1
Appearance Colorless liquid
Odor ether-like (threshold 39.8 ppm)
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
Critical point (T, P) 545 K (272 °C), 4.87 MPa
Miscible
log P −0.54
Vapor pressure 9.71 kPa (at 20 °C (68 °F; 293 K))
530 μmol/(Pa·kg)
Acidity (pKa) 25
UV-vismax) 195 nm
Absorbance ≤ 0.10
−28.0×10−6 cm3/mol
1.344
Viscosity 0.350 mPa·s (20 °C (68 °F; 293 K))
3.92 D
Thermochemistry
91.69 J⋅K−1·mol-1
149.62 J⋅K−1·mol-1
40.16 to 40.96 kJ⋅mol−1
−1256.03 to −1256.63 kJ⋅mol−1
Enthalpy of fusion fHfus)
8.167 kJ⋅mol−1 (crystalline to liquid)
  • 33.225 kJ⋅mol−1 (25 °C (77 °F; 298 K))
  • 29.75 kJ⋅mol−1 (81.6 °C (178.9 °F; 354.8 K))
Hazards
GHS labelling:
Danger
H225, H302+H312+H332, H319
P210, P233, P240, P241, P242, P243, P261, P264, P270, P271, P280, P301+P312+P330, P303+P361+P353, P304+P340+P312, P305+P351+P338, P337+P313, P370+P378, P403+P235, P501
NFPA 704 (fire diamond)
2
3
0
Flash point 2.0 °C (35.6 °F; 275.1 K)
523.0 °C (973.4 °F; 796.1 K)
Explosive limits 4.4%–16.0%
Lethal dose or concentration (LD, LC):
  • 2 g/kg (dermal, rabbit)
  • 2.46 g/kg (oral, rat)
  • 617 mg/kg (oral, mouse)
  • 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)
  • 6.022 mg/L (mouse, 4 hr)
16,000 ppm (dog, 4 hr)
NIOSH (US health exposure limits):
PEL (Permissible)
40 ppm (70 mg/m3, TWA)
REL (Recommended)
20 ppm (34 mg/m3, TWA)
IDLH (Immediate danger)
500 ppm
Related compounds
Related alkanenitriles
Supplementary data page
Acetonitrile (data page)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Y verify (what is YN ?)
Infobox references

Acetonitrile, often abbreviated MeCN (methyl cyanide), is the chemical compound with the formula CH3CN and structure H3C−C≡N. 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. The N≡C−C skeleton is linear with a short C≡N distance of 1.16 Å.

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