Which of the following is antiaromatic?

Name: Exam Paper Generator | JEE NEET Paper Generator | Vedclass
Brand: Vedclass
Rating: 5 (35 reviews)

Question

(B) To determine if a compound is antiaromatic,it must satisfy the following conditions:$1$. It must be cyclic and planar.$2$. It must be fully conjug

Vedclass · Accepted Answer

Cyclopentadienyl cation

Vedclass · Answer

(B) To determine if a compound is antiaromatic,it must satisfy the following conditions:$1$. It must be cyclic and planar.$2$. It must be fully conjugated.$3$. It must have $4n$ $\pi$ electrons (where $n = 1, 2, 3, ...$).Let's analyze the options:$A$: Cyclopropenyl cation has $2$ $\pi$ electrons ($4n+2$ with $n=0$),so it is aromatic.$B$: Cyclopentadienyl cation has $4$ $\pi$ electrons ($4n$ with $n=1$),so it is antiaromatic.$C$: Benzene has $6$ $\pi$ electrons ($4n+2$ with $n=1$),so it is aromatic.$D$: Cycloheptatrienyl cation has $6$ $\pi$ electrons ($4n+2$ with $n=1$),so it is aromatic.Therefore,the cyclopentadienyl cation is antiaromatic.

Column-$I$	Column-$II$
$(A)$ Carbocation	$(1)$ Cyclohexane and $1$-hexene
$(B)$ Nucleophile	$(2)$ Conjugation of electrons of $C-H$ $\sigma$-bond with empty $p$-orbital present at adjacent positively charged carbon
$(C)$ Hyperconjugation	$(3)$ $sp^{2}$ hybridised carbon with empty $p$-orbital
$(D)$ Isomers	$(4)$ Ethyne
$(E)$ $sp$ hybridisation	$(5)$ Species that can receive a pair of electrons
$(F)$ Electrophile	$(6)$ Species that can supply a pair of electrons

Similar Questions

Total number of $\alpha$-hydrogen in the given compound is

Which of the following compounds has a center of symmetry?

The following compounds are identical with respect to:

Total number of possible stereoisomers of dimethylcyclopentane is $....$

Vedclass Test Series

Exam Paper Generator

Online Exam Module