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Assertion (A) The compound tetraene has ...

Assertion (A) The compound tetraene has the following structural formula.

It is cyclic and has conjugated `8pi`-electron system but it is not an aromatic compound.
Reason (R ) `(4n + 2)pi` electrons rule does not hold good and ring is not planar.

A

Both A and B are correct and R is the correct explanation of A

B

Both A and R are not correct

C

Both A and R are not correct

D

A is not correct but R is correct

Text Solution

Verified by Experts

The correct Answer is:
a
Both assertion and reason are correct and reason is the correct explanation of assertion .
According to Huckel rule Aromaticity is shown by compounds possessing following characteristics
(i) compound must be planar and cycilc
(ii) Complete delocalisation of `pi` electrons in the ring
(iii) Presence of conjugated `(4n+2) pi` electrons in the ring where n is an integer (n=0, 1, 2,...) cyclo octatetraeng (given ) has a tub like structure . It loses planaritt\y. No. of `pie^(-)` delocalised = 8 and n is not integer. Hence, cyclotatetraene is a non-aromatic compound.
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