In which of the following substituted amines will the rate of amine flipping be significantly slower at 25 °C compared to trimethylamine?

Question

TestHub · Accepted Answer

Concepts Used: Steric strain, Angle strain in transition state, Electronegativity effects (Inductive destabilization).

Detailed Step-by-Step Solution:

1. Amine flipping involves a sp² hybridized transition state with a bond angle of 120^∘.

2. In aziridines (3-membered rings), the ground state angle is ≈60^∘. Forcing it to 120∘ in the transition state creates massive angle strain.

3. Furthermore, the presence of an electronegative atom like Cl on Nitrogen increases the s-character of the lone pair, raising the inversion barrier (Bent’s Rule).

Correct Answer: N-chloro-2,2-dimethylaziridine

Chemistry - AMINES Question with Solution | TestHub

Options:

Doubts & Discussion