Radical Stability Practice Problems

Rationalize the ranking of the following ethers according to their ability to form explosive peroxides.

Ethers have the tendency to form explosive peroxides. Draw a plausible mechanism for the peroxide formation from the given ether. Assume the presence of a radical X• to begin the reaction.

Considering the relative stabilities of the resulting alkyl radicals, determine which of the indicated carbon-hydrogen bonds would have a higher value of the bond dissociation energy.

Considering the relative stabilities of the resultant free radicals, identify which of the indicated carbon-halogen bonds would have a higher value of the bond dissociation energy.

Considering the relative stabilities of the resultant alkyl radicals, indicate which of the marked carbon-hydrogen bonds would have a higher value of the bond dissociation energy.

Determine which of the following radicals is the most stable, and thus, is most likely to be produced from an ether.

Which of the following ethers most readily produces peroxide?

Among the following ethers, identify the one which is least apt to produce peroxide.

The following table shows a few common C–H bond dissociation energies for homolytic cleavages.

Write an equation to show how diphenylmethane reacts with an alkyl free radical to form a stable radical. Use the given information to explain why the formation of this radical is energetically favorable.

Write an equation with fishhook arrows that shows the formation of a relatively stable free radical from ascorbic acid and methyl free radical.

A graduate student was studying free radical halogenation reactions. She added NBS to a solution of 3-methylcyclopent-1-ene and irradiated the mixture with a sunlight lamp. After all of the added NBS was consumed, she found that the reaction resulted in four different isomeric products of the formula C₆H₉Br. Assuming that a Br radical initiates the reaction by abstracting an H atom, write chemical equations and draw the structures of four different radicals.

A graduate student was studying free radical halogenation reactions. She added NBS to a solution of 3-methylcyclopent-1-ene and irradiated the mixture with a sunlight lamp. After all of the added NBS was consumed, she found that the reaction resulted in four different isomeric products of the formula C₆H₉Br. Rank the four allylic radicals that produce the four isomeric products.

The following three alkenes are arranged in decreasing order of their bond rotational energy barriers. Explain the difference in bond rotation energies by considering what their transition states look like.