Steric Inhibition of Resonance

The most important condition for resonanace to occur is that the invovled atoms in resonating structure must be coplanar or nearly coplanar for maximum delocalisation. If this condition does not fulfil, involved orbitals cannot be parallel to each other and as consequence delocalisation cannot occur. Bulky groups present on adjacent atoms inhibit the planarity of atoms involved in resonance. this pehnomenon is known as steric inhibition of resonance. Steric inhibition of resonance has profound effect on Q. Arrange the following in the decreasing order of basicity: .

The most important condition for resonanace to occur is that the invovled atoms in resonating structure must be coplanar or nearly coplanar for maximum delocalisation. If this condition does not fulfil, involved orbitals cannot be parallel to each other and as consequence delocalisation cannot occur. Bulky groups present on adjacent atoms inhibit the planarity of atoms involved in resonance. this pehnomenon is known as steric inhibition of resonance. Steric inhibition of resonance has profound effect on Q. Which of the following is most acidic:

Assertion (A) : Ph overset (o+)(N_2) Br^(Θ) couples with N, N -dimethyl aniline (I) but not with 2,6, -dimethyl- N,N -dimethuyl aniline (II) Reason (R ): Due to steric inhibition of resonance , the p-position of (II) is not sufficiently activated fro the coupling reaction.

Assertion: Salicyclic acid is much strogest than its m-p -isomers and benzoic acid itself. Reason: It is due to steric inhibitation to resonance, as -OH group forces -COOH out of the plane of ring.

Assertion (A): 2,6-Dimethyl-4-nitrophenol (I) is more acidic than 3,5-dimethyl-4-nitrophenol (II). Reason (R ): It is due to the steric inhibition of the resonance of (-NO_(2)) group with two (Me) groups in (II).

Steric Inhibition Protection

Blocking enzyme action through blocking its active sites is (a) Allosteric inhibition (b) Feedback inhibition (c) Competitive inhibition (d) Non-competitive inhibition

Define resonance and resonance energy. What are the conditions for resonance?

An example of competitive inhibition of an enzyme is the inhibition of