How does the structure of an ether compare with the structure of a water molecule?

Ethers and water molecules share a fundamental structural relationship, as both are based on an oxygen atom bonded to two other atoms.1

• Water Molecule ($H_{2}O$): Consists of an oxygen atom bonded to two hydrogen atoms. Because the oxygen atom is highly electronegative, the O–H bonds are polar, allowing water molecules to engage in strong hydrogen bonding with one another.2
• Ether Molecule ($R–O–R$): Structurally, an ether is derived from a water molecule by replacing both hydrogen atoms with alkyl or aryl groups.1

The primary difference lies in the absence of the hydroxyl (–OH) group in ethers. Because ethers lack the strongly polarized O–H bonds found in water (and alcohols), ether molecules cannot form hydrogen bonds with each other. While they still possess nonbonding electron pairs on their oxygen atoms—allowing them to act as solvents by forming hydrogen bonds with other substances—this lack of self-association results in significantly lower boiling points compared to water and alcohols of similar molecular weight.1