Ether

Ether is a class of organic compounds that contain an ether group — an oxygen atom connected to two alkyl or aryl groups — of general formula R–O–R.

Nomenclature

The names for simple ethers (i.e. those with none or few other functional groups) are a composite of the two substituents followed by "ether."
IUPAC rules are often not followed for simple ethers. In the IUPAC nomenclature system, ethers are named using the general formula "alkoxyalkane", for example:

is methoxyethane. If the ether is part of a more complex molecule, it is described as an alkoxy substituent, so -OCH₃ would be considered a "methoxy-" group. The simpler alkyl radical is written in front, so CH₃-O-CH₂CH₃ would be given as methoxy(CH₃O)ethane(CH₂CH₃).

Physical properties

Ether molecules cannot form hydrogen bonds amongst each other, resulting in a relatively low boiling point compared to that of the analogous alcohols. The difference, however, in the boiling points of the ethers and their isometric alcohols become smaller as the carbon chains become longer, as the van der waals interactions of the extended carbon chain dominate over the presence of hydrogen bonding.

Ethers are slightly polar. Ethers are more polar than alkenes but not as polar as alcohols, esters, or amides of comparable structure. However, the presence of two lone pairs of electrons on the oxygen atoms makes hydrogen bonding with water molecules possible.

Ethers in general are of low chemical reactivity, but they are more reactive than alkanes.

Although ethers resist hydrolysis, they are cleaved by mineral acids such as hydrobromic acid and hydroiodic acid. Hydrogen chloride cleaves ethers only slowly. Methyl ethers typically afford methyl halides: