Ether

This article is about the functional group and category of chemicals. For the specific chemical also called "ether", see diethyl ether.

In organic chemistry, an ether is a part of a molecule called a functional group. An ether group is a structure where two carbon atoms are linked by chemical bonds to the same oxygen atom,^[1] and neither carbon has a double bond to another oxygen atom.

Shape of a general ether.

Chemicals that contain the ether group are also called ethers. Diethyl ether, tetrahydrofuran, and ethyl tert-butyl ether are examples of important ethers in the chemical industry.

Special types

An ether where the two carbon atoms are directly bonded to each other is an epoxide.^[2] Cyclic compounds containing multiple ether groups are called crown ethers.

When two ether groups share the same carbon atom, the compound is an acetal.^[3] An ether and −OH group on the same carbon is a hemiacetal.^[4]

Related groups

Ethers by definition do not have a C=O double bond on either of the carbons next to the oxygen. This bond changes how the chemical acts enough that if present, the chemical is no longer considered as an ether. If one carbon has this bond, the group is an ester; if both do, it is an acid anhydride.

A thioether is an ether where the oxygen atom is replaced by sulfur.

One or both carbon atoms may be replaced with silicon. Replacing one carbon atom gives a silyl ether,^[5] and replacing both gives a siloxane.^[6]