Bromoethane

Bromoethane, also known as ethyl bromide, is a chemical compound with the formula C2H5Br. This organobromine compound is a colorless liquid, although older samples can appear yellowish due to decomposition. It is commonly used as a refrigerant, fumigant, and in organic synthesis as an alkylating agent. Bromoethane has a sweet ether-like odor and is volatile and flammable.

Properties

Bromoethane is a halogenated hydrocarbon with a boiling point of 38.4°C and a melting point of -119°C. It is slightly soluble in water, but highly soluble in organic solvents such as ethanol, diethyl ether, and acetone. The compound's volatility and ability to donate an ethyl group make it a valuable chemical in various organic synthesis processes.

Synthesis

Bromoethane can be synthesized through several methods. The most common method involves the reaction of ethanol with hydrobromic acid (HBr), either as a gas or dissolved in water. This reaction can be accelerated by the presence of a catalyst such as sulfuric acid:

C2H5OH + HBr → C2H5Br + H2O

Another method involves the free radical halogenation of ethane with bromine (Br2), using light or heat to initiate the reaction.

Uses

Bromoethane is primarily used in organic synthesis as an alkylating agent, introducing an ethyl group into molecules to form new chemical compounds. Its applications include the synthesis of pharmaceuticals, agrochemicals, and other organic compounds. Additionally, it has been used as a lead scavenger in antiknock fluids in gasoline, although this use has declined due to environmental concerns.

In the past, bromoethane was also used as a refrigerant and a fumigant for soil and storage facilities. However, its use in these applications has decreased due to its toxicity and the availability of safer alternatives.

Health and Safety

Exposure to bromoethane can occur through inhalation, ingestion, or skin contact. It is a potent neurotoxin and can cause respiratory distress, central nervous system depression, and kidney and liver damage with acute or chronic exposure. Safety measures include using bromoethane in well-ventilated areas, wearing protective clothing, and adhering to occupational exposure limits.

Environmental Impact

Bromoethane is a volatile organic compound (VOC) that can contribute to atmospheric pollution and the formation of ground-level ozone. It is also a potential greenhouse gas. Measures to reduce environmental exposure include controlling emissions and using less hazardous substances when possible.

Regulation

The use and handling of bromoethane are regulated under various international and national laws to protect human health and the environment. This includes regulations on air quality, chemical safety, and occupational exposure limits.

See Also

• Alkylating agent
• Organobromine compound
• Halogenation
• Toxicology