Hückel's 4n+2 rule (Hückel 1931, degenerate-perturbation theory on the cyclic MO ladder): a planar, fully-conjugated, monocyclic system with (4n+2) π-electrons is aromatic; with 4n π-electrons it is anti-aromatic (destabilised, will…
Hückel's 4n+2 rule (Hückel 1931, degenerate-perturbation theory on the cyclic MO ladder): a planar, fully-conjugated, monocyclic system with (4n+2) π-electrons is aromatic; with 4n π-electrons it is anti-aromatic (destabilised, will…