Which of the following pairs of structures are resonance structures:
(I) and
(II) and
(III) and
(IV) $(C_{6} H_{5})_{2}$ $CH$ – $and (C_{6} H_{5})_{2} C =$

Question

Which of the following pairs of structures are resonance structures: (I) and (II) and (III) and (IV) ( C 6 ​ H 5 ​ ) 2 ​ CH – and ( C 6 ​ H 5 ​ ) 2 ​ C =

TestHub · Accepted Answer

Resonance changes only electron placement, not atomic positions or sigma connectivity. In I , the lone pair/positive charge is delocalized between oxygen, carbon and nitrogen. II depicts the same symmetric aromatic triol through alternative pi-bond placement. III changes a carbonyl-containing ring system into a cyclic hemiaminal, changing sigma bonding. IV transfers a hydrogen between carbon and oxygen and is a tautomeric pair. Therefore only I and II are resonance pairs.

Chemistry - GOC Question with Solution | TestHub

Options:

Doubts & Discussion