Acetonitrile
[CAS# 75-05-8]

Identification

• Classification: Organic raw materials >> Nitrile compound
• Name: Acetonitrile
• Synonyms: Methyl cyanide; Cyanomethane
• Molecular Formula: C₂H₃N
• Molecular Weight: 41.05
• CAS Registry Number: 75-05-8
• EC Number: 200-835-2
• SMILES: CC#N

Properties

• Density: 0.7857
• Melting point: -46 °C
• Boiling point: 81-82 °C
• Refractive index: 1.343-1.345
• Flash point: 2 °C
• Water solubility: miscible

Safety Data

• Hazard Symbols: GHS02;GHS07 Danger
• Risk Statements: H225-H302-H312-H319-H332
• Safety Statements: P210-P261-P264-P280-P337+P313-P301+P312-P302+P352-P303+P361+P353-P304+P340-P305+P351+P338-P321-P330-P362+P364

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Flammable liquids	Flam. Liq.	2	H225
Acute toxicity	Acute Tox.	4	H302
Eye irritation	Eye Irrit.	2	H319
Acute toxicity	Acute Tox.	4	H332
Acute toxicity	Acute Tox.	4	H312
Acute toxicity	Acute Tox.	3	H311
Acute toxicity	Acute Tox.	3	H331
Specific target organ toxicity - single exposure	STOT SE	3	H336
Specific target organ toxicity - single exposure	STOT SE	3	H335
Eye irritation	Eye Irrit.	2A	H319
Chronic hazardous to the aquatic environment	Aquatic Chronic	2	H411
Skin corrosion	Skin Corr.	1A	H314
Skin corrosion	Skin Corr.	1B	H314
Carcinogenicity	Carc.	1B	H350
Acute toxicity	Acute Tox.	3	H301
Eye irritation	Eye Irrit.	2	H320
Skin sensitization	Skin Sens.	1A	H317

• Transport Information: UN 1648

Discovery and Applications

Acetonitrile, a colorless and volatile organic compound with the chemical formula C2H3N, is a simple nitrile and the simplest aliphatic nitrile. Its discovery dates back to the early 19th century when it was first synthesized by the German chemist Justus von Liebig in 1832. Liebig obtained acetonitrile through the reaction of sodium cyanide with methyl iodide. The compound has since gained significance in various industrial and scientific applications due to its unique chemical properties.

One of the most notable applications of acetonitrile is as a solvent. It possesses excellent solvating properties, making it an ideal choice for a wide range of organic reactions and processes. Acetonitrile is commonly used in the extraction and purification of natural products, pharmaceuticals, and agrochemicals. Its polar aprotic nature allows it to dissolve both polar and nonpolar compounds, further enhancing its utility in chemical synthesis and analysis.

In the pharmaceutical industry, acetonitrile plays a critical role in high-performance liquid chromatography (HPLC), a technique used for separating, identifying, and quantifying compounds in a mixture. Acetonitrile is often employed as a mobile phase solvent in HPLC due to its ability to dissolve a broad spectrum of analytes while providing sharp and well-defined peaks. This application is essential for quality control and the development of new drugs.

Additionally, acetonitrile is used in the production of various chemicals, including acetic acid, acrylonitrile, and pharmaceuticals. It serves as a precursor in the synthesis of the important compound acrylonitrile, which is a key ingredient in the production of synthetic fibers, plastics, and rubber. Furthermore, acetonitrile is utilized in the manufacture of some agricultural chemicals, contributing to the formulation of herbicides and pesticides.

The electrochemical industry also leverages acetonitrile for its excellent solvent properties. It is often used in the development of electrolyte solutions for lithium-ion batteries and other electrochemical systems. Its low viscosity and high dielectric constant enhance the performance of these batteries, making acetonitrile an important component in the growing field of energy storage technology.

Despite its many beneficial applications, acetonitrile must be handled with care due to its toxicity and environmental concerns. Prolonged exposure to acetonitrile can lead to adverse health effects, including irritation of the skin, eyes, and respiratory system. Furthermore, its potential for environmental contamination has led to increased scrutiny regarding its use and disposal. As such, industries employing acetonitrile are encouraged to implement strict safety measures and consider alternative solvents when feasible.

In summary, acetonitrile is a versatile compound with a rich history of discovery and significant applications across various fields, including organic chemistry, pharmaceuticals, and electrochemistry. Its unique properties make it an invaluable tool in both industrial processes and scientific research, while ongoing efforts to address safety and environmental concerns will shape its future use in technology.

References

1890. über die Constitution einiger Derivate des Cyanamids. Monatshefte für Chemie und verwandte Teile anderer Wissenschaften, 11(1).
DOI: 10.1007/bf01540732

1894. Ueber die Umwandlung des Acetonitrils und seiner Homologen im Thierkörper. Archiv für experimentelle Pathologie und Pharmakologie, 34(5).
DOI: 10.1007/bf01824916

1896. Ueber Bildung des Harnstoffes durch Oxydation. Archiv für experimentelle Pathologie und Pharmakologie, 37(1).
DOI: 10.1007/bf01966253