Question

What is the reactivity order of halogen acids with ethers?

Answer 1

Ethers

• Ethers are a type of chemical molecule in which the oxygen atom is connected to two alkyl or aryl groups by an ether group.
• The name Ether comes from the Latin word aether, which means "to burn."
• Ethers are frequently combustible at ambient temperature and under high pressure.
• $\mathrm{R}-\mathrm{O}-\mathrm{R},\mathrm{R}-\mathrm{O}-\mathrm{R}\text{'},\mathrm{R}-\mathrm{O}-\mathrm{Ar},\mathrm{or}\mathrm{Ar}-\mathrm{O}-\mathrm{Ar}$ is the generic formula for ether, where $\mathrm{R}$ represents an alkyl group and $\mathrm{Ar}$ represents an aryl group.

Reactivity of Halogen with Ethers

• The nucleophilic attack of the halide ion on the protonated ether molecule causes halogen acids to cleave ethers.
• The more nucleophilic the halide ion is, the more reactive the halogen acid is.
• Because the halide ion's nucleophilicity follows the sequence,

${\mathrm{I}}^{–}>{\mathrm{Br}}^{–}>{\mathrm{Cl}}^{–}$

$\mathrm{HI}>\mathrm{HBr}>\mathrm{HCl}$

Hence it is the reactivity order of halogen acids with ethers.