Question

How many compounds among the following compounds show inductive, mesomeric as well as hyperconjugation effects?

Answer 1

Correct Answer: 4

To identify compounds exhibiting inductive, mesomeric, and hyperconjugation effects, each compound is analyzed:

1. C₆H₅CH₂OCH₃:
   • Inductive Effect: Present (electronegative oxygen).
   • Mesomeric Effect: Present (benzene ring participation in resonance).
   • Hyperconjugation: Absent (no adjacent C-H bonds to a positively charged or double-bonded carbon).
2. C₆H₅CH₂CH=CH₂:
   • Inductive Effect: Present (σ-bond polarization).
   • Mesomeric Effect: Present (benzene ring).
   • Hyperconjugation: Present (adjacent C-H bonds to the double bond).
3. C₆H₅CH₂CH(NO₂)CH₃:
   • Inductive Effect: Present (electronegative nitro group).
   • Mesomeric Effect: Absent (nitro group not directly conjugated with the benzene ring).
   • Hyperconjugation: Present (C-H bonds adjacent to the benzene ring).
4. C₆H₅CH₂CH₂Cl:
   • Inductive Effect: Present (electronegative Cl).
   • Mesomeric Effect: Absent (no conjugation with the benzene ring).
   • Hyperconjugation: Not significant.
5. C₆H₅NO₂:
   • Inductive Effect: Present (nitro group).
   • Mesomeric Effect: Present (nitro group conjugated with benzene).
   • Hyperconjugation: Absent (lacks appropriate hydrogen atoms).
6. C₆H₅CH=CHC₆H₅:
   • Inductive Effect: Present (polarizable π bonds).
   • Mesomeric Effect: Present (both benzene rings contribute).
   • Hyperconjugation: Present (C-H bonds adjacent to double bonds).
7. C₆H₅CH(CH₃)COCH₃:
   • Inductive Effect: Present (CO group).
   • Mesomeric Effect: Present (CO group conjugates with benzene).
   • Hyperconjugation: Present (methyl groups).
8. C₆H₁₁CH₃:
   • Inductive Effect: Present (alkyl group polarization).
   • Mesomeric Effect: Absent (cyclohexane ring does not permit conjugation).
   • Hyperconjugation: Present (multiple C-H bonds).

Based on this analysis, the compounds demonstrating all three effects are: C₆H₅CH₂CH=CH₂, C₆H₅CH=CHC₆H₅, C₆H₅CH(CH₃)COCH₃. There are 3 such compounds. This count does not align with the specified range (4, 4), suggesting a potential discrepancy in the expected range.