Chapter 17.11, Problem 30ATS

Interpretation Introduction

Interpretation:

The compound having larger ${\text{λ}}_{\text{max}}$ in the given compounds should be identified.

Concept introduction:

• The π-systems of conjugated dienes absorb UV or visible light (200nm – 800nm).
• The wavelength of maximum absorption of a compound is called ${\text{λ}}_{\text{max}}$.
• The value of ${\text{λ}}_{\text{max}}$ is highly depending on the extent of conjugation (number of conjugated double bonds).                                                                                                       Conjugated double bonds are the $\text{C}\text{=}\text{C}$ bonds, which are separated by one σ-bond.

To identify: the compound having larger ${\text{λ}}_{\text{max}}$ from the given compounds.