Chemical Name: Acetonitrile
CAS Number: 75-05-8
Formula: C2H3N
Molecular Weight: 41.052 g/mol
Synonyms: Cyanomethane, Ethanenitrile, Ethyl nitrile, Methanecyano, Methanecarbonitrile, Methyl cyanide (MeCN), etc.
Appearance: Acetonitrile is a colorless to pale yellow liquid with an aromatic odor reminiscent of ether.
Density: Its density is approximately 0.78745 g/cm³ at 15°C.
Melting Point: -45°C
Boiling Point: 81.6°C at 760 Torr (or 80-82°C in some sources)
Flash Point: Varies, but typically around 48°F (or 12.8°C by closed-cup method)
Refractive Index: 1.331-1.345 (dependent on temperature)
Water Solubility: Miscible with water and many organic solvents.
Vapor Pressure: 72.8 mm Hg at 20°C
Vapor Density: 1.41 (vs air)
Stability: Acetonitrile is a relatively stable compound but can undergo addition reactions due to its triple bond between carbon and nitrogen.
Reactivity: It reacts with halogenated hydrocarbons, hydrogen sulfide, alcohols in the presence of acids, acids or anhydrides, and hydroxylamine. It can also undergo hydrolysis in the presence of acids or bases to generate amides and further to acids.
Flammability: Acetonitrile is flammable in the presence of an open flame, high temperature, or oxidants. It decomposes upon heating and releases highly toxic cyanide and nitrogen oxide fumes.
Explosivity: It forms explosive mixtures with air within certain concentration ranges (3.0-17% V/V).
Solvent: Acetonitrile is widely used as a solvent in analytical chemistry, such as in thin-layer chromatography, paper chromatography, spectrophotometry, and polarography. It is also used as a solvent in high-performance liquid chromatography (HPLC) due to its non-absorbance of ultraviolet light between 200nm and 400nm.
Intermediate: It serves as an important intermediate in the synthesis of various nitrogen-containing compounds and is used in the preparation of many pharmaceuticals and pesticides.
Extraction: Acetonitrile is used in extractive distillation to separate butadiene from C4 hydrocarbons and other hydrocarbons like propylene, isoprene, and methylacetylene.
Other Applications: It is also used in the extraction of fatty acids from vegetable oils and fish oils, as a semiconductor cleaner, in textile dyeing, and as an effective stabilizer for chlorinated solvents.