Detailed Notes: Ethers

Nomenclature (NCERT- 12th Chemistry TextBook Chapter 11 - Alcohols, Phenols, Ethers Section 11.8)

• Ethers are compounds that have two alkyl or aryl groups bonded to an oxygen atom.
• The general formula for an ether is R-O-R'.
• The IUPAC nomenclature for ethers is as follows:
  • The longest carbon chain containing the oxygen atom is identified as the parent chain.
  • The alkoxy group (-OR’) is named as a substituent on the parent chain.
  • If there are multiple alkoxy groups, they are numbered according to their position on the parent chain.
  • The name of the ether is written as “alkoxyalkane.”

Physical Properties (NCERT- 11th Chemistry TextBook Chapter 12 - Aldehydes, Ketones, and Carboxylic Acids)

• Ethers are generally colorless liquids with a characteristic odor.
• They are immiscible with water but soluble in organic solvents.
• The boiling points of ethers are lower than those of the corresponding alcohols.
• The density of ethers is lower than that of water.

Chemical Properties (NCERT- 12th Chemistry TextBook Chapter 11: Alcohol, Phenols, Ethers

• Ethers are relatively inert compounds, but they can undergo a variety of chemical reactions.
• The most common reactions of ethers are cleavage reactions, nucleophilic substitution reactions, and electrophilic addition reactions.
• Cleavage reactions involve the breaking of the C-O bond.
• Nucleophilic substitution reactions involve the replacement of the alkoxy group with another nucleophile.
• Electrophilic addition reactions involve the addition of an electrophile to the double bond of the ether.

Williamson Ether Synthesis (NCERT 12th Chemistry TextBook Chapter 13: Amines)

• The Williamson Ether Synthesis is a method for preparing symmetrical and unsymmetrical ethers.
• The reaction involves the reaction of an alkoxide ion with an alkyl halide.
• The mechanism of the Williamson Ether Synthesis involves an SN2 reaction between the alkoxide ion and the alkyl halide.
• The synthesis of unsymmetrical ethers requires the use of a primary alkyl halide and a secondary or tertiary alkyl halide.
• The synthesis of symmetrical ethers requires the use of two primary alkyl halides or two secondary alkyl halides.

Reactions of Epoxides (NCERT - 12th Chemistry TextBook Chapter 10: Alcohols, Phenols and Ethers)

• Epoxides are cyclic ethers that contain a three-membered ring.
• Epoxides are highly reactive and can undergo a variety of reactions, including nucleophilic substitution reactions, epoxide ring-opening reactions, and epoxide rearrangements.
• The nucleophilic substitution reactions of epoxides involve the attack of a nucleophile on the epoxide ring.
• The epoxide ring-opening reactions involve the breaking of the C-O bond in the epoxide ring.
• The epoxide rearrangements involve the migration of a group from one carbon atom to another carbon atom in the epoxide ring.

Crown Ethers and Cryptands (NCERT 12th Chemistry TextBook Chapter 10: Alcohols, Phenols, and Ethers)

• Crown ethers and cryptands are cyclic polyethers that contain multiple oxygen atoms.
• Crown ethers and cryptands are used as complexing agents.
• Crown ethers and cryptands can form complexes with metal ions.
• The structure-property relationships of crown ethers and cryptands are important for understanding their ability to form complexes with metal ions.

*Industrial Applications of Ethers (NCERT 11th & 12th Chemistry TextBooks - Various Chapters as a Solvent)

• Ethers are used as solvents in a variety of industries.
• Ethers are used as extractants in the petroleum industry.
• Ethers are used as fuel additives.
• Ethers are used in the manufacture of plastics, resins, and adhesives.