Which of the following compounds are aromatic according to Huckel's rule?

Explanation

A. The compound has `8pi` electrons . It will be non-aromatic. Both rings are non-benzenoid.
B. The compound is aromatic. It has `6pie^(-)` delocalised electron (`4 pie^(-)+2` ione pair electrons), all the four carbon atoms and the NN atom are `sp^(2)` hybridised.
C. The compound contains `6pi` electrons but in the ring hence it is non-aromatic.
D. `10pie^(-)` obeying Huckel rule and the ring is planar . It is aromatic.
E. In this compound one six membered planar ring has `6pie^(-)` although it has `8pi` electrons in two rings. It is therefore aromatic.
F. It has `14pi` electrons in conjugation and in the planar ring , Huckel rule is verified. It will be aromatic.