Ethers are versatile organic compounds with an oxygen atom bridging two carbon groups. They're named using common or IUPAC systems, with alkoxy groups formed by replacing hydrogen with an -OR group. Ethers play a crucial role in organic chemistry due to their unique properties and reactivity.

Ethers have higher boiling points than alkanes but lower than alcohols. They're polar and make great solvents for organic reactions. However, ethers pose safety risks due to flammability and peroxide formation. Proper storage and handling are essential to prevent accidents in the lab.

Ethers

Naming of ethers and alkoxy groups

• General formula for ethers: $R-O-R'$
  • $R$ and $R'$ represent alkyl (carbon and hydrogen chains) or aryl (aromatic rings) groups connected by an oxygen atom
• Common names for ethers formed by naming alkyl groups attached to oxygen in alphabetical order, followed by "ether"
  • Ethyl methyl ether represents $CH_3-O-CH_2CH_3$ with a methyl group and an ethyl group connected by an oxygen atom
• IUPAC names for ethers generated by naming the larger alkyl group as an alkoxy substituent on the smaller alkyl group
  • Methoxyethane represents $CH_3-O-CH_2CH_3$ with a methoxy group ($-OCH_3$) attached to an ethane molecule
• Alkoxy substituents formed by replacing a hydrogen on a carbon with an $-OR$ group, where $R$ is an alkyl group
  • Named by replacing the "-yl" suffix of the alkyl group with "-oxy"
    • Methoxy ($-OCH_3$) formed from methyl ($CH_3-$)
    • Ethoxy ($-OCH_2CH_3$) formed from ethyl ($CH_3CH_2-$)

Physical properties of ethers vs hydrocarbons

• Ethers have higher boiling points than alkanes of similar molecular weight
  • Presence of oxygen atom allows for dipole-dipole interactions between ether molecules, increasing intermolecular forces
• Ethers have lower boiling points than alcohols of similar molecular weight
  • Alcohols can form stronger hydrogen bonds between molecules, while ethers cannot form hydrogen bonds
• Ethers are polar molecules due to the difference in electronegativity between the oxygen and carbon atoms
  • Oxygen atom has a partial negative charge, while carbon atoms have a partial positive charge
• Polarity of ethers makes them better solvents for polar compounds compared to non-polar hydrocarbons
  • Diethyl ether commonly used as a solvent for organic reactions involving polar reactants or products

Safety hazards of ethers

• Ethers are highly flammable due to their volatility and low flash points
  • Ether vapors can travel considerable distances from the source and ignite, causing dangerous flash fires
• Ethers can form explosive peroxides upon exposure to air and light
  • Peroxides are unstable compounds that can detonate with heat, friction, or impact
• Ethers with $\alpha$-hydrogen atoms (on the carbon atom next to the oxygen) are most prone to peroxide formation
  • Diethyl ether, tetrahydrofuran (THF), and 1,4-dioxane are common examples of ethers that readily form peroxides
• Store ethers in a cool, dry, well-ventilated area away from heat, sparks, and flames to minimize fire risk
  • Use air-tight containers with tight-fitting lids to minimize exposure to air and light that promote peroxide formation
• Add stabilizers like butylated hydroxytoluene (BHT) to ether containers to prevent peroxide formation
• Label ether containers with the date received and opened, and discard after the recommended shelf life to avoid using potentially dangerous peroxide-contaminated ethers

Ether Synthesis and Reactions

• Williamson ether synthesis: A common method for preparing ethers by reacting an alkoxide with an alkyl halide
• Ether synthesis can also involve the dehydration of alcohols using acid catalysts
• Cyclic ethers (e.g., tetrahydrofuran) are formed through intramolecular reactions
• Crown ethers are cyclic ethers with multiple oxygen atoms that can complex with metal ions
• Ether cleavage reactions can break the C-O bond, often using strong acids or reducing agents