Molecule of the Day: Diethyl ether
Diethyl ether (C4H10O), also known as ethoxyethane, is a colourless, volatile liquid with a sweet, pungent smell at room temperature and pressure.
It is a commonly used polar aprotic organic solvent used in laboratories, and has low solubility in water. Therefore, it can be used in liquid-liquid solute extractions in conjunction with water.
Diethyl ether was also historically used as an anaesthetic - it was first used as such in the 19th century, and gradually replaced chloroform as an anaesthetic due to its lower toxicity. However, in recent years, its use has been largely supplanted due to its flammability and side effects such as vomiting and nausea.
Diethyl ether can be produced by the acid-catalysed condensation reaction of two ethanol molecules, which is how it is produced industrially as a by-product of acid-catalysed hydration of ethylene to produce ethanol:
Alternatively, it can be synthesised using the Williamson ether synthesis, in which an ethoxide salt is reacted with an ethyl halide to produce diethyl ether via an SN2 reaction:
While diethyl ether has a low toxicity, it has a tendency to react with oxygen in the air to produce highly shock- and heat-sensitive explosive peroxides, which is why old bottles of diethyl ether should be disposed of carefully as they may detonate.