CH3CN

CH3CN, commonly known as acetonitrile or methyl cyanide, is the simplest nitrile. It is a colorless, volatile liquid with a faint odor. It boils at 81.6 C and has a density of about 0.786 g/mL at 20 C. It is highly polar and is a prototypical polar aprotic solvent; its dielectric constant is around 37, and it is miscible with water and many organic solvents. The nitrile group makes CH3CN relatively chemically stable, yet it can be hydrolyzed under acidic or basic conditions to give acetamide (CH3CONH2) and, with more aggressive conditions, acetic acid (CH3COOH).

Industrially, acetonitrile is produced mainly as a byproduct of acrylonitrile manufacture via ammoxidation of propylene. It is also formed in other nitrile production schemes and sold as a purified specialty solvent.

Applications include use as a widely used solvent in organic synthesis, particularly for reactions involving organometallic reagents; it is a common mobile phase component in high-performance liquid chromatography (HPLC) and LC-MS. It is also employed as a solvent and electrolyte component in lithium-ion and other battery chemistries, and as a chemical intermediate in pharmaceuticals and agrochemicals.

Safety and handling: acetonitrile is flammable and can be irritating to skin, eyes, and the respiratory tract. Inhalation or significant skin contact may cause dizziness, headache, or other central nervous system effects. It can release cyanide upon metabolic processing, posing additional toxicological hazards. It should be stored in tightly closed containers, away from heat and oxidizers, and handled in a well-ventilated area with appropriate personal protective equipment.