Question

Benzoquinone can be used to inhibit radical polymerizations. This compound reacts with a radical intermediate, \(\mathrm{R} \cdot\), to form a less reactive radical that does not participate in chain propagation steps and, thus, breaks the chain.

Short answer

Question: Explain how Benzoquinone inhibits radical polymerizations by reacting with a radical intermediate (R•) to form a less reactive radical. Answer: Benzoquinone inhibits radical polymerizations by reacting with a radical intermediate (R•) to form a complex. This complex then forms a less reactive radical, which does not participate in chain propagation steps, ultimately breaking the chain and inhibiting the polymerization process.

Step-by-step solution

Identify the radicals

First, we need to identify the radicals involved in this reaction. We are given that Benzoquinone reacts with a radical intermediate (R•). Benzoquinone structure: O || C-C || \ O C \ R•

React Benzoquinone with the radical intermediate

The reaction of Benzoquinone with the radical intermediate (R•) can be represented as follows: Benzoquinone + R• → Complex Chemical formula: C_6H_4O_2 + R• → Complex

Formation of a less reactive radical

The complex formed in Step 2 will eventually form a less reactive radical which does not participate in chain propagation steps. This can be represented as: Complex → Less reactive radical

Breaking the chain

As the less reactive radical does not participate in the chain propagation steps, it results in breaking the chain of the radical polymerization process. The final reaction can be summarized in the following form: Benzoquinone + R• → Less reactive radical This breaks the chain and inhibits radical polymerizations.