Which of the following compounds are aromatic according to Huckel’s rule?
(A) The number of electrons in the compound are8. According to Huckle’s Rule it should satisfy the formula (4n+2) electrons. For n=1, it gives value of 6 and for n=2, it gives 10, thus the given compound is not aromatic.
(B) The lone pair on nitrogen and the two double bonds which are in delocalisation contribute to 6 eldectrons which is a Huckle Number and thus the compound can be stated as aromatic.
(C) There are 3 double bonds implying 6 electrons, which is according to Huckle’s Rule and thus can be considered aromatic. (but there are carbon atoms which are non-planar indicating otherwise)
(D) Naphthalene is planar and has 10 electrons which fits in Huckel’s rule, thus its aromatic
(E) In this compound the aromaticity is not valid as the number of electrons is only 8 which does not satisfy Huckels Rule
(F) The entire structure is planar, and the number of double bonds is 7 so electrons are 14, which fits for n=3 as an integer in Huckel rule so the compound is aromatic.