Q12 · CSIR-NET Chemistry, June 2011
Paper: CSIR-NET June 2011 · Subject: Organic Chemistry · Chapter: General Organic Chemistry · Topic: Aromaticity · Marks: 2 · Difficulty: Easy
Among the carbocations given below 
(A) 
(B) 
(C)
(A) (B) (C)(a)A is homoaromatic, B is antiaromatic and C is aromatic.
(b)A is aromatic, B is antiaromatic and C is homoaromatic.
(c)A is antiaromatic, B is aromatic and C is homoaromatic.
(d)A is homoaromatic, B is aromatic and C is antiaromatic.
Answer
Answer: A ✓ checked by 4AB · confidence high
Explanation
A is the homotropylium ion: 6π through the CH₂ bridge, homoaromatic. B, the cyclopentadienyl cation, has 4π and is antiaromatic. C, the cyclopropenyl cation, has 2π and is aromatic (a).
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