Hückel's rule in organic chemistry, also known as the 4n + 2 rule
Hückel method, a method for the determination of energies of molecular orbitals
•
Hückel's rule, a method of determining aromaticity in organic molecules
Hückel's rule | Huckel's rule | Hückel method | Debye–Hückel equation |
The Hückel method can be derived from the Ritz method, with a few further assumptions concerning the overlap matrix S and the Hamiltonian matrix H.
It was pointed out by Henry Rzepa that the conversion of intermediate 5 to 6 can proceed by either a Hückel or a Möbius transition state.
Edgar Heilbronner had described twisted annulenes which had Möbius topology, but in including the twist of these systems, he concluded that Möbius systems could never be lower in energy than the Hückel counterparts.