Chemistry · Electronic displacement in a covalent bond: Inductive effect, electromeric effect, resonance and hyperconjugation

Its basic strength is more than 1 dimethyl amino naphthalene due to:

Its basic strength is \( 10^{10} \) more than 1 dimethyl amino naphthalene due to:

  • A. resonance
  • B. steric inhibitation of resonance
  • C. ortho effect
  • D. hyperconjugation

Step-by-step solution

Steric inhibition of resonance (SIR) occurs when bulky substituents near the amino group prevent the lone pair from delocalizing into the aromatic ring. This increases electron density on nitrogen, enhancing basicity. For 1-dimethylaminonaphthalene derivatives, such inhibition can cause a dramatic increase in basic strength, as much as 10^10-fold, because resonance stabilization of the conjugate acid is diminished. Options like resonance, ortho effect, or hyperconjugation do not account for such a large basicity difference.
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