Given below are two statements. One is labelled as Assertion A and the other is labelled as Reason R . Assertion A : 6 Annulene. 8 Annulene and cis - 10 Annulene, are respectively aromatic, not-aromatic and aromatic. ​​​​​​​ Reason R : Planarity is one of the requirements of aromatic systems. In the light of the above statements, choose the most appropriate answer from the options given below.

Step-by-step solution

In 10 -Annulene - the hydrogen atoms in the 1 and 6 position interfere with each other and force the molecule out of planarity If this annulene with five cis double bonds were planar, each internal angle would be 144 ° . Since a normal double bond has bond angle of 120 ° , this would be from ideal. This compound can be made but it does not adopt a planar conformation and therefore is not aromatic even though it has ten π electrons.