Chapter 11, Problem 11.52P

Interpretation Introduction

Interpretation:

The reason for the restricted rotation about the $\text{C}-\text{N}$ bond is to be explained. Also, the types of bonding involved are to be shown.

Concept introduction:

When bonds in a molecule can be expressed by different Lewis structures then resonance structures are used to depict the bonding in that molecule. This resonance structure has the same placement of atoms but different locations of bonding and lone pairs of electrons also one resonance form can be converted into another by moving lone pairs to bonding positions, and vice versa.

More important resonance structure selected as follows:

1. Always prefer smaller formal charge over the larger formal charge.

2. Always prefer the different non zero formal charge on adjacent atoms instead of the same non zero formal charge.

3. A more negative formal charge must be located on the most electronegative atom.