Acetonitriles

Acetonitrile

Names
Preferred IUPAC name Acetonitrile
Systematic IUPAC name Ethanenitrile
Other names Cyanomethane Ethyl nitrile Methanecarbonitrile Methyl cyanide
Identifiers
CAS Number	75-05-8 Y
3D model (JSmol)	Interactive image
Beilstein Reference	741857
ChEBI	CHEBI:38472 Y
ChemSpider	6102 Y
ECHA InfoCard	100.000.760
EC Number	200-835-2
Gmelin Reference	895
MeSH	[www.nlm.nih.gov/cgi/show_data.php?acc={{{MeSH}}} {{{MeSH}}}]
PubChem CID	6342
RTECS number	AL7700000
UNII	Z072SB282N Y
UN number	1648
InChI InChI=1S/C2H3N/c1-2-3/h1H3 Y Key: WEVYAHXRMPXWCK-UHFFFAOYSA-N Y
SMILES CC#N
Properties
Chemical formula	C2H3N
Molar mass	41.05 g·mol−1
Appearance	Colorless liquid
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
Specific heat capacity (C)	91.69 J/(K·mol)
Std molar entropy (So298)	149.62 J/(K·mol)
Std enthalpy of formation (ΔfHo298)	40.16–40.96 kJ/mol
Std enthalpy of combustion (ΔcHo298)	−1256.03 – −1256.63 kJ/mol
Hazards
Safety data sheet	See: data page
GHS pictograms
GHS signal word	DANGER
GHS hazard statements	H225, H302, H312, H319, H332
GHS precautionary statements	P210, P280, P305+351+338
NFPA 704	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)
LCLo (lowest published)	16,000 ppm (dog, 4 hr)
US health exposure limits (NIOSH):
PEL (Permissible)	TWA 40 ppm (70 mg/m3)
REL (Recommended)	TWA 20 ppm (34 mg/m3)
IDLH (Immediate danger)	500 ppm
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  (what is YN ?)
Infobox references

Acetonitrile is the chemical compound with the formula CH
3CN. 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.

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, 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.

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

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.