Ether
Definition and meaning of Ether in chemistry.
Ether is an organic compound in which an oxygen atom connects two carbon-containing groups, written as R-O-R'. No hydrogen atom attaches directly to that oxygen. This structure gives ethers a bent shape similar to water, but with very different chemical behavior.
In more detail
The oxygen in an ether carries two lone pairs of electrons, which makes ethers weakly polar and able to act as weak Lewis bases, donating an electron pair to other molecules. Because ethers lack an O-H bond, they cannot hydrogen-bond with each other the way alcohols do.
This missing hydrogen bonding gives ethers noticeably lower boiling points than alcohols of similar molar mass. It also makes ethers far less reactive. They resist oxidation, dehydration, and reactions with most common acids and bases.
This chemical stability, combined with the ability to dissolve both polar and nonpolar substances, makes ethers valuable laboratory solvents. They are especially important in Grignard reactions and other reactions involving reactive organometallic compounds, since ethers dissolve these sensitive reagents without reacting with them. Despite their general stability, many ethers slowly react with oxygen in the air to form dangerous peroxide compounds, which can be shock-sensitive and explosive when concentrated.
Cyclic ethers, such as tetrahydrofuran, share these same general properties but have their oxygen atom built into a ring rather than a straight chain.
Key facts
| General formula | R-O-R' |
|---|---|
| Functional group | Ether linkage (C-O-C) |
| Common example | Diethyl ether, C4H10O |
| Field | Organic Chemistry |
| Boiling point trend | Lower than alcohols of similar molar mass |
| Storage hazard | Slowly forms explosive peroxides on exposure to air and light |
Diethyl ether, CH3CH2-O-CH2CH3, is a volatile, highly flammable liquid. It was once widely used as a surgical anesthetic in the 1800s and early 1900s. Today it remains a common laboratory solvent, though chemists must store it carefully and test old bottles for peroxides before distilling it. Distilling an old bottle of ether to dryness can concentrate any peroxides that have formed, creating a serious explosion risk in the lab. Diethyl ether's fruity smell and high volatility also made it easy to administer by simple inhalation during early surgeries.
Frequently asked questions
Why are ethers less reactive than alcohols?
Ethers lack an O-H bond, so they cannot hydrogen-bond to each other or easily undergo oxidation, esterification, or deprotonation the way alcohols can.
Are ethers dangerous to store?
Yes. Many ethers, including diethyl ether and tetrahydrofuran, slowly form explosive peroxides on exposure to air and light, so they should be stored in dark containers and tested before distillation.
Why are ethers good solvents for Grignard reactions?
Ethers dissolve reactive organometallic reagents without reacting with them, and their weak Lewis base oxygen helps stabilize the reagent in solution.
Related terms
Sources & references
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