In high school books, Huckel's rule is used for determining aromaticity. We were taught this example
Huckel's rule is limited to monocyclic systems. We were taught to find aromaticity by -
- looking for a closed loop. The two loops that were pointed out have been drawn (in pink) in the diagram above.
- Applying Huckel's rule to it i.e counting the number of $\pi$ electrons and then applying the 4n+2 formula for aromatic compounds and 4n for anti.
No explanation was provided as to why this concept works on the grounds of 'this is out of syllabus'.
I have multiple questions regarding this 'closed loop' concept
- What is it really called?
- How does this loop methodology work?
- What would happen if the inner loop was aromatic and outer anti aromatic?
(the example has both loops anti)