Cycloheptatrienyl Cation and Aromaticity

Cycloheptatriene is a neutral monocyclic unsaturated hydrocarbon with seven carbon atoms. One carbon in the ring is sp3 hybridized, which breaks the continuous overlap of p orbitals. Even though the ring has three double bonds and 6 π electrons, cycloheptatriene is not aromatic because the p orbitals do not form one uninterr...

Cycloheptatriene is another neutral monocyclic unsaturated hydrocarbon with an odd number of carbon atoms.

It has six π electrons, fulfilling Hückel's 4n + 2 rule.

However, the intervening sp³ carbon disrupts the delocalization of these π electrons; therefore, neutral cycloheptatriene is not aromatic.