Chapter 1, Problem 49P

Interpretation Introduction

Interpretation:

The structure that is not a permissible contributing one amongst the given structures is to be determined; the remaining three structures are to be ranked in the order of their contribution to the resonance hybrid; and the electron movement that connects these three resonance contributors is to be shown using curved arrows.

Concept introduction:

According to the resonance concept, Lewis formulas that have different distribution of electrons in their structure can be written for a single molecule. Lewis formulas that confer to a resonance hybrid can be made easier to understand by using curved arrows to represent the delocalized electrons.

Each structure contributing to resonance must have an equal total number of valence electrons and the same value of net charge. Among the various Lewis formulas written for a molecule, the formal charges on individual atoms may vary. Each structure contributing to resonance must have the same number of unshared electrons.

When two or more structures satisfy the octet rule, the major contributor structure is the one with the smallest separation of oppositely charged atoms. The contributor structure with the least number of formal charges is more stable.