Acetonitrile

Acetonitrile is an organic compound with the formula CH₃CN. It is the simplest nitrile and is a colorless liquid with a slightly sweet odor. Acetonitrile is used primarily as a solvent in the purification of butadiene in refineries and as a solvent in the manufacture of pharmaceuticals and photographic film. It is also a valuable solvent in liquid chromatography.

Properties

Acetonitrile is a polar solvent, similar to ethanol and water, but with a higher ability to dissolve non-polar compounds. It has a boiling point of 82°C and a melting point of -45.7°C. Acetonitrile can form azeotropes with many other solvents, including water, making it useful in various distillation processes.

Production

The primary method for producing acetonitrile is as a byproduct of the production of acrylonitrile, which is synthesized from propylene and ammonia. Acetonitrile can also be produced directly by the ammoxidation of ethane or from ethylene and hydrogen cyanide.

Applications

1. 1. 1. Solvent Use ###

Acetonitrile's main use is as a solvent in the pharmaceutical industry, where it is used in the synthesis of peptides and nucleic acids, and in the purification of steroids. It is also used in the production of vitamins and antibiotics. In analytical chemistry, acetonitrile is used as a solvent in high-performance liquid chromatography (HPLC), owing to its ability to dissolve a wide range of compounds.

1. 1. 1. Specialty Chemicals ###

It serves as a starting material in the synthesis of amino acids, vitamins, and flavors and fragrances. Acetonitrile is also used in the manufacture of pesticides, herbicides, and plasticizers.

Safety

Acetonitrile is flammable and can form explosive mixtures with air. It is also toxic if ingested, inhaled, or absorbed through the skin, with potential effects on the central nervous system, respiratory system, and liver. Safety measures include using acetonitrile in well-ventilated areas, wearing protective clothing, and storing it away from heat and open flames.

Environmental Impact

While acetonitrile is not considered a major environmental pollutant, it can contribute to air and water pollution if not properly handled and disposed of. It is biodegradable and does not accumulate in the environment.