308

Unit 3
Elements of Organic Chemistry

3-8. ETHERS

An ether can be thought of as a hydrocarbon derivative of water where the two hydrogens of water are replaced by hydrocarbon groups. Thus, ethers have the general structural formula R-O-R' where R and R' represent any two hydrocarbons, which may be alike or different. Some examples of ethers are:

CH3 – CH2 –- O – CH2 – CH3      CH3 – O – CH3      CH2 = CH – O – CH3

Properties of Ethers. Ether molecules are slightly polar, but cannot form hydrogen bonds with each other since they do not have a hydrogen atom attached directly to an oxygen atom. Therefore, they have about the same boiling points and melting points as alkanes of similar molecular weights.

M.W. Boiling Point
CH3 – CH2 – CH2 – CH2 – CH2 – CH2 – CH3 100 98C
CH2 – CH2 – CH2 – CH2 – CH3 102 100C

Reactions of Ethers. Since ether molecules are slightly polar and have an oxygen atom in their structure, they can form hydrogen bonds with water. This property accounts for the fact that ethers are slightly soluble in water. Chemically, ethers are inert except for the oxidation reaction. Ethers are oxidized in the presence of oxygen to form peroxides, which are explosive when concentrated.

Uses of Ethers. Medicinally, ethers are used as general anesthetics. They are also used as solvents. Many of you are involved with ordering and storing ethers.