question_answer

Which of the following is the correct order of stability of the given compounds?

(I)

(II)

(III)

A) \[I>II>III\]       

B)        \[III>II>I\]        

C) \[II>I>III\]        

D)        \[II>III>I\]

Correct Answer: A

Solution :

[a]                                   

(I) \[\Rightarrow \] Aromatic \[6\pi \bar{e}'s\] system in conjugation .

(II) Non-aromatic, \[8\pi \bar{e}'s\] system but ring is not planar, so not anti-aromatic but non-aromatic.

(III) \[\Rightarrow \] Anti-aromatic \[8\pi \bar{e}'s\] in conjugation .

Stability order: Aromatic > Non-aromatic > Anti-aromatic. \[(I)>(II)>(III)\]