Chapter 17, Problem 17.1P

Interpretation Introduction

Interpretation: All possible resonance structures for the antihistamine diphenhydramine are to be drawn.

Concept introduction: Resonance structure is a blend of two or more Lewis structures. Resonance structures are represented by a double headed arrow between the structures.

Answer to Problem 17.1P

All possible resonance structures for the antihistamine diphenhydramine are,

Explanation of Solution

The given structure of antihistamine diphenhydramine is shown below.

Figure 1

The given structure contains oxygen and nitrogen atoms and these atoms are not conjugated with any double bond. Thus, the lone pairs of these atoms do not participate in the resonance. Hence, possible resonance structures for the antihistamine diphenhydramine are shown below.

Figure 2

Conclusion

All possible resonance structures for the antihistamine diphenhydramine are shown in Figure 2.