See image — GOC and Organic Chemistry Basics Chemistry Question

💡 Solution & Explanation

# Radical Stability Analysis Radical stability is determined by **hyperconjugation** and **resonance stabilization**. Let me analyze each radical: **Structure Identification:** - **I**: Cyclohexyl radical (primary, saturated) - **II**: Cyclohexadienyl radical (allylic, one C=C adjacent) - **III**: Cyclohexadienyl radical (allylic, one C=C adjacent) — same as II - **IV**: Benzyl-like radical (benzylic position, extensive conjugation with aromatic ring) - **V**: Phenyl radical (on benzene ring itself, disrupts aromaticity) **Stability Order Logic:** 1. **IV (Benzylic)** — Most stable. The radical is conjugated with the aromatic π-system through resonance. The unpaired electron can delocalize into the ring via multiple resonance structures. 2. **II & III (Allylic)** — Secondary allylic radicals stabilized by conjugation with one C=C double bond and hyperconjugation. Both are equivalent. 3. **I (Cyclohexyl)** — Primary saturated radical, stabilized only by hyperconjugation from adjacent C-H bonds. 4. **V (Phenyl)** — Least stable. Placing a radical directly on the aromatic ring disrupts aromaticity and removes the stabilizing π-electron cloud. Very unstable. **Correct Order:** $$\text{IV} > \text{II} > \text{I} > \text{III} > \text{V}$$ **Answer: (C)** ✓ This matches option C perfectly.