Planar aromaticity of DNh-symmetrical systems as a perturbed two-dimensional (2D) rigid rotor

Energy levels for D _{N h} -symmetrical cyclic polyenes with planar aromaticity were obtained using two-dimensional (2D) rigid rotor as the zeroth approximation. The addition of nuclei was simulated by the cosine-type potential and treated at the first-order perturbation theory. The result is qualitatively equivalent to that obtained using Hückel’s molecular orbital theory. As an addition, the energetic shift between σ and π orbitals is obtained using the model of electron oscillating around the center of a positively charged ring.