Which of the following are not aromatic ?

Options

A. A, C, E
B. B, E, F
C. B, C, F
D. C, D, E

Answer

B

Explanation

Key Idea conditions for species to be an aromatic are :
(i) The aromatic structures follows Huckel's rule, i.e. species have `(4n+2) pi`-electrons in its structure. Where n = integer 0, 1, 2, 3, ..... So on.
(ii) Should be planar ring structure.
(A) It follows Huckel's rule and has planar structure thus, is an aromatic `( :' n=1, pi r^(-) = 6)`.
(B) It does not follow Huckel's rule ( `:'` has `8pi` electrons with `n=2`)
(C) It follows Huckel's rule and has planar structure. Thus, is an aromatic `( :' n=1, pi e^(-) =6)`.
(D) It follows Huckel's rule and has planar structure as it has `n=3` and `14 pi` electrons.
(E) It does not follow Huckel's rule, thus is not an aromatic compound `(n=1, pi e^(-)=4)`.
(F) It also does not follow Huckel's rule. Thus, is not an aromatic `(n=0, pi e^(-)=4)`
Hence, species (B), (E) and (F) are not aromati and option (b) is the correct answer.